Science for Cultural Heritage: Technological Innovation and Case Studies in Marine and Land Archaeology in the Adriatic Region and Inland

VII INTERNATIONAL CONFERENCE ON SCIENCE, ARTS AND CULTURE

SCIENCE FOR CULTURAL HERITAGE Technological Innovation and Case Studies in Marine and Land Archaeology in the Adriatic Region and Inland

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www.ecsac.eu

VII INTERNATIONAL CONFERENCE ON SCIENCE, ARTS AND CULTURE

SCIENCE FOR CULTURAL HERITAGE Technological Innovation and Case Studies in Marine and Land Archaeology in the Adriatic Region and Inland

August 28-31, 2007 • Veli Lošinj, Croatia

Editors

M. Montagnari Kokelj M. Budinich University of Trieste, Italy

C. Tuniz ICTP, Italy

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SCIENCE FOR CULTURAL HERITAGE Technological Innovation and Case Studies in Marine and Land Archaeology in the Adriatic Region and Inland Veli Lošinj, Croatia 28–31 August 2007 eds. C. Tuniz, M. Montagnari Kokelj and M. Budinich Copyright © 2010 by The Abdus Salam International Centre for Theoretical Physics

ISBN-13 978-981-4307-06-2 ISBN-10 981-4307-06-8

Printed in Singapore.

EH - Science for Cultural Heritage.pmd

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1/4/2010, 2:30 PM

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INTRODUCTION M. BUDINICH1, M. MONTAGNARI KOKELJ1, C.TUNIZ2 1 University of Trieste and 2ICTP, Trieste – Italy

The Lo!inj series of Conferences (see http://www.ecsac.eu/) focus on interdisciplinary themes, with the aim to promote a forum involving researchers, scholars and students from natural and social sciences and humanities. This interdisciplinary dialogue and the active involvement of local communities and non-specialists, with particular attention to young people, is one of the main objectives of the European Centre for Science Arts and Culture (ECSAC, http://www.ecsac.eu/), the main organizer of the conferences. ECSAC has its headquarters in Mali Lo!inj, Croatia, while the Managing Committee and the Secretariat are based in Trieste, Italy, hosted by the Consortium for the Promotion of Study and Research in Physics, at the ICTP – the Abdus Salam International Centre for Theoretical Physics. ECSAC’s President, Paolo Budinich, at the same time President of the Trieste International Foundation for the Progress and Freedom of Science, has been one of the key figures in the process started in the 1960s to develop the “Trieste System” as an international institutional scheme that promotes advanced knowledge involving also scientists and students from developing countries. ECSAC, ICTP and the Trieste University, promoters of the Lo!inj Conference, belong to the Trieste System, as well as SISSA / ISAS - the International School for Advanced Studies, AREA Science Park and the Consortium mentioned above, who all supported the project. Besides these partners, the institutional representatives of UniAdrion - the Virtual University of the Adriatic-Ionian Basin (a net including both ECSAC and Trieste University) and IAEA - the International Atomic Energy Agency, as well as scientific scholars from many European countries have guaranteed the international dimension of the Lo!inj events. The 7th Lo!inj International Conference on Science, Arts and Culture was titled “Science for Cultural Heritage: Technological Innovation and Case Studies in Marine and Land Archaeology in the Adriatic Region and Inland”. It was inspired by recent studies on the ancient bronze Apoxyomenos, found in 1999 in Veli Lo!inj waters, carried out by the Hrvatski Restauratorski Zavod

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(Croatian Institute of Restoration) in collaboration with Opificio delle Pietre Dure, the famous restoration centre based in Florence, Italy.. The Conference was held on 28 - 31 August in Lo!inj and involved 50 scientists, archaeologists and restoration experts mainly from north-eastern Italy, Carinthia, Slovenia and Croatia, but also from other prestigious European centres. The aim of the conference was to discuss the contribution of physics and other sciences in archaeological research and in the preservation of cultural heritage. Considering that the mission of ECSAC is to promote the interaction among the diverse cultures of the peoples from the lands on the Adriatic and Ionian seas, the major themes were related to the history and pre-history of this region, from greek-roman archaeology on the eastern Adriatic coasts to the palaeoanthropology of the Neanderthals of the Vindija caves in Croatia, from the Roman city of Aquileia to the pleistocenic cave of Homo heidelbergensis in the Karst of Visogliano (Trieste), from the Roman ship Julia Felix of the Grado lagoon to the ancient bronze Apoxyomenos of the Veli Lo!inj waters. A variety of scientific disciplines provide tools and methods that are crucial to reconstruct humanity’s past and to preserve material remains that witness the evolution of human culture. Geology reconstructs the history of terrestrial environments, critical for the evolution and dispersal of humans. Chemistry explains reactions that modify materials left by human activities, including the destructive effects of pollution. Biology has a critical role in archaeology, particularly with the recent progress in the analysis of DNA in ancient organic materials. Physics has a special role in archaeology and cultural heritage, providing a variety of non-invasive analytical methods that can characterise ancient materials. These methods include new microscopes based on synchrotron radiation, high-energy ions, neutrons, lasers and other radiations or particles that can detect in-situ the structure and composition of art objects and archaeological remains, with resolution at molecular and atomic level. High resolution satellite imagery allows the prospection of archaeological sites over distances of several kilometres. Also the time dimension is critical in archaeology. Physicists have developed clocks based on natural radioactivity that provide chronologic information on time scales from centuries to million years, from the Middle Ages to the Pleistocene. Finally, the analysis of certain isotopes such as nitrogen, calcium and strontium provide information that can be used to reconstruct diets, diseases and migrations of ancient human populations. The conference has offered the opportunity to promote the debate among scholars and students from natural sciences, humanities and social sciences,

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considering the impact of the most recent scientific and technologic developments in applications to art and archaeology.

Acknowledgements We would like to extend our warmest thanks to the Mayor of Mali Lo!inj Gari Cappelli who always helped and sustained the organization of the series of conferences on Science and Culture (see http://www.ecsac.eu/) in the beatiful island of Lo!inj. This year in particular we would like to thank the Town Council of Veli Losinj who offered the newly refurbished theater, now Kulturni Dom, of Veli Losinj. This conference wouldn't have been possible without the unbelievable dedication, kindness and patience of Morena Petrich who was responsible for the secretariat and for all the organizative matters.

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CONTENTS Introduction Program

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Archaeological and Archaeometric Data in the Study of the Athlete of Croatia M. Michelucci

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Ion Beam Techniques for Analysis of Cultural Heritage Objects: Collaboration between the Ruđer Bošković Institute and the Croatian Conservation Institute S. Fazinić, I. Božičević, Z. Pastuović, M. Jakšić, D. Mudronja, K. Kusijanović, M. Braun and V. Desnica

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Study by Mobile Non-Destructive Testing of the Bronze Statue of the “Satiro” of Marsala G. Guida, D. Artioli, S. Ridolifi and G. E. Gigante

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Archaeometric Measurements with PIXE in Slovenia Ž. Šmit In Situ Chemical Composition Analysis of Cultural Heritage Objects Using Portable X-Ray Fluorescence Spectrometry D. Wegrzynek, E. Chinea-Cano, A. Markowicz, S. Bamford, G. Buzanich , P. Wobrauschek, Ch. Streli, M. Griesser, K. Uhlir and A. Mendoza-Cuevas Integrated Geophysical Techniques for the High-Resolution Study of Archaeological Sites M. Pipan and E. Forte Thermoluminescence Dating and Cultural Heritage M. Martini and E. Sibilia

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55

69

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New X-Ray Digital Radiography and Computed Tomography for Cultural Heritage F. Casali, M. Bettuzzi, R. Brancaccio and M. P. Morigi Cosmic Rays for Archaeology G. Giannini

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Some Examples of Examination, Characterisation, Analysis & Conservation Techniques Dedicated to Archaeological Artefacts J. L. Boutaine

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Presentation of DEMGOL: Online Etymological Dictionary of Greek Mythology E. Pellizer

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Building Up an Archaeological Restoration & Conservation Department in Friuli-Venezia Giulia F. Lo Schiavo

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Relative Sea Level Changes by Using Archaeological Markers: The INTERREG Italia-Slovenia Project “Alto Adriatico” S. Furlani, F. Antonioli and R. Auriemma

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Digitization and Multispectral Analysis of Artistic Objects: Exemplary Cases and Web Documentation G. Maino and S. Massari

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Actuopalaeontology: A Polyfunctional Tool for Archaeology G. Bressan, G. Fonda, S. Kaleb, R. Melis, M. E. Montenegro, P. Mourguiart, N. Pugliese, R. Riccamboni, A. Russo, N. Sodini and G. Tromba

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Robotics Tools for Underwater Archaeology G. Conte, S. Zanoli, D. Scaradozzi and L. Gambella

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Accelerators and Radiation for Art and Archaeology C. Tuniz

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The 14C Contribution to the Protohistory of Friuli (North-Eastern Italy) P. Càssola Guida

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Serpentinite Shaft-Holed Axes in the Caput Adriae: Preliminary Results and Perspectives Based on X-Ray Computerized Microtomography F. Bernardini, E. M. Kokelj, N. Sodini, D. Dreossi, S. Favretto, G. Demarchi, A. Alberti and F. Princivalle

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Mummies – A Special Report Results of CAT Scan Analyses of Egyptian Mummies in the Civico Museo di Storia ed Arte of Trieste M. V. Torlo

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ANGLE Software for Semiconductor Detector Gamma-Efficiency Calculations and Possibilities for Its Applications to Cultural Heritage Objects Characterization S. Jovanovic and A. Dlabac Hominid Fossils as Universal and National Cultural Heritage: An Essay on Past and Present Attitudes Towards the Ownership of Hominid Fossils and the Question of Repatriation P. V. Tobias

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PROGRAM OF THE CONFERENCE International Conference "Science for Cultural Heritage" Veli Lo!inj, Croatia, August 28-31, 2007

Tuesday, AUGUST 28, 2007 14.00 – 16.00 16.00 – 16.25

Registration Welcome and Greetings of the Authorities Chairperson: C. Tuniz (ICTP) P. Budinich, ECSAC M. Mu!i" , President of Council of Mali Lo#inj T. Morin, Local Community G.C. Ghirardi, Consortium for Physics M. Montagnari Kokelj, University of Trieste

The state of archaeometry in the Caput Adriae regions Chairperson: M. Montagnari Kokelj (University of Trieste) 16.25 – 16.50

16.50 – 17.15

17.15 – 17.40 17.40 – 18.05

M. Michelucci, former Director Archaeological Section Opificio delle Pietre Dure, Florence Archaeological and archaeometrical data in the study of the Athlete of Croatia S. Fazini", Ru$er Bo#kovi" Institute, Zagreb Ion Beam Techniques for Analysis of Cultural Heritage Objects: Collaboration between the Ru!er Bo"kovi# Institute and the Croatian Conservation Institute G. Gigante, University La Sapienza, Roma New archaeometric approaches to study large bronze statues %. &mit, University of Ljubljana Archaeometric measurements with PIXE in Slovenia Welcome Cocktail in Punta Hotel

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Wednesday, AUGUST 29, 2007 Scientific methods and techniques: new perspectives Chairperson: C. Tuniz (ICTP) 9.00 – 9.25 9.25 – 9.50 9.50 – 10.15 10.15 – 10.40 11.15 – 11.40

D. Wegrzynek, IAEA In situ chemical composition analysis of cultural heritage objects using portable X-ray fluorescence spectrometry M. Pipan, University of Trieste Integrated geophysical techniques for the high-resolution study of archaelogical sites M. Martini, AIAr Luminescence dating techniques for the cultural heritage F. Casali, University of Bologna New X-ray Digital Radiography and Computed Tomography for Cultural Heritage G. Giannini, INFN Trieste Cosmic Rays for Archaelogy

12.00 – 16.00

Archeological boat tour to the Athlete of Croatia finding site

16.25 – 16.50

J.-L. Boutaine, C2RMF, Paris Some exemples of examination, characterisation, analysis & conservation techniques dedicated to archaelogical artefactcs N. Sodini, Sincrotrone Trieste – University of Firenze Characterization of archeological wood by means of X-ray computed micro-tomography A. Mereu and R. Riccamboni, University of Trieste, DiSGAM Pen-based Technology in geosites field surveying: mapping, drafting and data collecting using a Tablet PC

16.50 – 17.15 17.15 – 17.40

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Archaeometry and society Chairperson: M. Michelucci (University of Pisa) 17.40 – 18.05 18.30 – 18.55

18.55 – 19.20

E. Pellizer, University of Trieste The other “Great Code” – Heritage of ancient Greek and Roman culture in an on-line, multilingual, dictionary F. Lo Schiavo, Superintendent Cultural Heritage Regione Friuli Venezia Giulia Building up an archaeological restoration & conservation department in Friuli-Venezia Giulia R. Costa, University of Trieste, Facoltà di Architettura Unesco Chair Trieste The master plans for Aquileia and non-invasive surveys

Thursday, AUGUST 30, 2007

Marine Archaelogy: the sea and its relics Chairperson: M. Budinich (University of Trieste) 9.00 – 9.25

9.25 – 9.50 9.50 – 10.15

10.15 – 10.40

S. Furlani et alii, University of Trieste Relative Sea Level Changes by using archaeological markers: the INTERREG Italia-Slovenia Project “Alto Adriatico” S. Massari, ENEA Digitization and multispectral analysis of artistic objects: exemplary cases and web documentation G. Bressan, S. Favretto, G. Fonda, S. Kaleb, R. Melis, M.E. Montenegro, N. Pugliese, R. Riccamboni, A. Russo, N. Sodini, G. Tromba, F. Vita (ATA Group) Actuopalaeontology: a polyfunctional Tool for Archaeology G. Conte, Polytechnic University of Marche Robotics tools for underwater archaelogy

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Land Archaelogy: Prehistoric sites and materials Chairpersons: G. Boschian (University of Pisa) and A. Coppa (University La Sapienza, Roma) 11.00 – 11.25 11.25 – 11.50

11.50 – 12.15

G. Boschian, University of Pisa Homo heidelbergensis environment and behaviour: the Visogliano site (Trieste) A. Coppa, University La Sapienza, Roma A new classification approach: Neural networks analysis by using the Self-Organizing Maps (SOMs) applied to human fossil dental morphology C. Tuniz, ICTP Dating human dispersal and impact during the Pleistocene

Land Archaelogy: Ancient humans Chairpersons: G. Boschian (University of Pisa) and A. Coppa (University La Sapienza, Roma) 16.00 – 16.25 16.25 – 16.50 16.50 – 17.15

17.15 – 18.40

18.40 – 19.05

P. Càssola Guida, University of Udine The 14C contribution to the protohistorical reconstruction in north-eastern Italy F. Bernardini et alii, University of Trieste Greenstone artefacts in prehistory: preliminary results and perspectives based on X-ray computerized microtomography M. Vidulli, Civic Museums, Trieste Mummies – a special report results of CAT scan analyses of egyptian mummies in the 'Civico Museo di Storia ed Arte' of Trieste (italian: Tomografia assiale computerizzata delle tre mummie egizie dei Civici Musei di Storia ed Arte di Trieste) S. Jovanovic, University of Montenegro Possibilities of ANGLE software for semiconductor detector gamma-efficiency characterization in neutron activation analysis of cultural heritage objects E. Cacciatore, Centro Regionale per la Progettazione e il Restauro della Regione Siciliana, Palermo Villa romana del Casale of Piazza Armerina. Restoration and Management

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Friday, AUGUST 31, 2007 Round Table: Archaeometry: from research to high formation Chairperson: M. Martini (AIAr) 9.00

F. Lo Schiavo, Superintendent Cultural Heritage Regione FVG G. Gigante, University La Sapienza, Roma M. Montagnari Kokelj, University of Trieste M. Tenconi, University of Padova C. Tuniz, ICTP Trieste F. Bradamante, University of Trieste J.-L. Boutaine, C2RMF, Paris G.C. Ghirardi, University of Trieste A. Coppa, University La Sapienza, Roma G. Giannini, University of Trieste R. Costa, University of Trieste Students of Uniadrion Universities

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ARCHAEOLOGICAL AND ARCHAEOMETRIC DATA IN THE STUDY OF THE ATHLETE OF CROATIA MAURIZIO MICHELUCCI

A few days after the bronze known as the Athlete of Croatia emerged from Lo!inj waters (fig. 1), the Hrvatstki Restauratorski Zavod (HRZ, the Croatian restoration institute) took the lead of the restoration project, involving in it also the Archaeological Division of the ‘Opificio delle Pietre Dure’ (OPD, a special institute of the Italian Ministry for Cultural Heritage).

Figure 1

OPD performed the preliminary inspections and gamma-graphic analysis in the training pool of Lo!inj Maritime Police (fig. 2) where the bronze was initially placed. These preliminary surveys (fig. 3) confirmed the good preservation of the artefact under the thick layer of organogenic concretions1 (fig. 4). Successively the long and difficult restoration process was performed in ! Photos kindly granted from journal “Archeologia Viva”, OPD, HRZ and by M. Michelucci.

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Figure 2

Figure 3

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See A. A LDROVANDI, S. PORCINAI, Indagine gammagrafica, in “Apoxyomenos - L’Atleta della Croazia”, edited by M. Michelucci, Firenze 2006, pgs. 110-112.

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Figure 4

the well equipped HRZ laboratories in Zagreb by Giuliano Tordi – who in the meantime retired from OPD – and Antonio "erbeti#, from HRZ. During the entire restoration process all operations were preceded and accompanied by a considerable number of chemical, physical and metallurgical analysis on samples of the statue performed in OPD scientific laboratories. Analysis focused on alteration and corrosion products as well as on the metallic alloy, especially in those areas which were more likely to be of interest for the casting techniques and the successive refinements processes underwent by the statue before its loss, as it clearly appeared since the beginning of the restoration process2. OPD sent some of the organic remains found in the interior of the statue to the Beta Analytic Laboratories of Miami (Florida) for 14C analysis. The results of this work are known: the big and beautiful bronze statue entirely freed from marine concretions was presented to the general public in 2

OPD - HRZ collaboration was constant and fruitful along the whole, demanding, restoration process, thanks to good relations, not only on the scientific plan, but especially of reciprocal esteem and friendship, between the superintendants heading OPD – G. Bonsanti and successively C. Acidini – and the Direction of the restoration works, i.e. F. Meder, HRZ Director, and M. Domijan, Chief Conserver of the Croatian Ministry of Culture.

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two big expositions in Zagreb and Florence – the latter in the prominent site of Palazzo Medici Riccardi (fig. 5) – together with a richly illustrated catalogue. The Florence exposition also concisely presented results of the scientific analysis.

Figure 5

This is one of the not-so-frequent cases in which the humanistic science of archaeology and the so-called ‘hard’ sciences happily and tightly joined their efforts in the critical interpretation of the found data and the subsequent analysis. There are some uncertainties still to be resolved by further experimentation and research, but this joint effort lead to common results on the statue meaning and dating, provenience, final destination and loss circumstances – data of paramount importance for the history of art, metallurgy and restoration. I will remember here some of them: the statue is surely a late republican Roman copy (someone prefer to say replica) of a Greek original. This dating results from a series of data critically considered. Alloy analysis on a series of duly mapped samples (fig. 6) didn’t give univocal data: as one can easily see from the attached table (fig. 7), those performed with the SEM/EDS method in non corroded areas indicated a percentage of lead between 1.6% and 3.3%, while those performed with the ICP/AES method on the same samples were

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definitely higher (16.2% to 20%). As it should always be the case, chemical analysis data need an adequate interpretation to assess their validity, especially

Figure 6

Figure 7

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when applied to cultural heritage elements. As it is well known, the ICP/AES method cannot discriminate among areas more or less affected by corrosion, as the results refer to the average value measured in the entire sample. This means that the higher solubility – and dispersion – of copper corrosion by-products in marine waters tend to indicate higher concentrations of lead than copper, altering the data of the original alloy composition. The SEM/EDS analysis is more selective and allows more precise investigations in areas not touched by corrosion processes; it consequently produces more reliable data on the original alloy composition. This is confirmed by the fact that SEM/EDS analysis on highly corroded samples – and thus affected from dispersion of copper alteration by-products – gave results similar to those of the ICP/AES method, indicating high percentages of lead3. It would be interesting to verify if previously published alloy composition data of bronze statues rescued from sea bed have allowed for these factors and methodological considerations. It is known that, since the middle of the Republican Era and for the entire Imperial Age, the alloy of big and small bronze statues in Rome was added with a considerable amount of lead in order to lower both fusion temperature and costs even if that implied a consistent degradation of the artefact quality, making it brittler. This was not true in archaic and classic Greek production nor in the first Hellenistic age, a technical fact that has considerable consequences on dating. We saw that the alloy composition of the Athlete of Croatia contains a low percentage of lead; if this scientific finding had been uncritically associated to the artistic style of the work, we would have been brought to consider the artefact as a Greek original of about 360 BC. However, like in a police investigation, other archaeological, analytical and technical factors have been taken into consideration, and their union brought to a much later dating of the bronze fusion. The data obtained from the 14C analysis of three organical finds discovered in the interior of the statue indicate chronological intervals going from the end of the 2nd century BC to the second half of the 2nd century AD. The latter datum comes from a burnt wooden splinter coming from the right leg – providing an important contribution to the dating of the shipwreck – while the former (110 BC to 70 AD) refers to a peach stone bitten by a small rodent, abundant remains of whose burrow have been found4.

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See C. G. LALLI, G. LANTERNA, D. PINNA, S. PORCINAI, M.RIZZI, I. TOSINI, Indagini diagnostiche, In “Apoxyomenos...”, pgs.117-118 See Appendici scientifiche, ibidem, pgs. 121-123.

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The fact that mice could have made their burrow – the lining has also been found, and was made of an herb that palaeobotanical analysis revealed to be typical of a ruin-like environment – within the statue indicates that the statue was abandoned, full of gaps and leaning on the ground. And it could not have been otherwise since a vast portion of the back of the right thigh – which sustains the whole weight of the statue – had a big gap due to a casting fault (fig. 8) making it impossible for the statue to stand.

Figure 8

The whole casting didn’t turn out well: this is testified not only by the above mentioned conspicuous gap on the supporting leg, but also by the large number of patches – some of which irregularly trapezoidal in shape and huge in size – applied on gas pockets, gaps, and craters widespread on the whole body surface (fig. 9).

Figure 9

The good composition of the bronze alloy heavily clashes, and with full evidence, with the nasty yield of the casting. All these data seem to have little in

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common, but they assume particular relevance if combined with other general archaeological and historical information: 1. in Greek sculpture, good bronze alloys, preserving the classic age composition, are rarely assessed even in the early imperial age (some bronze portraits – certainly of imperial age – have been cast with this alloy, almost without lead); 2. the usage of big, convex patches of irregular shape to correct casting faults in bronze statues spreads in the 1st century BC. 3. it is assessed that in the late 1st century BC, continental Greece experiences a generalized economic and social crisis as a consequence of Sulla’s plunders, repeated civil wars and lack of investments; on the other hand the Micrasiatic area undergoes economic expansion – its big towns, former capitals of the Hellenistic reigns, would have become, with a growing urban development, the metropolis of the middle and late Roman empire; 4. the only bronze replica – almost of the same size of the Lo!inj statue – comes from a gymnasium of the late 1st century AD in Ephesus, Anatolia (fig. 10).

Figure 10

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If we consider all these data and refer them to our statue, we get a general picture that brings to the following conclusions: the casting of the statue was poor because they wanted to use a good alloy which required a blast furnace reaching very high temperatures in an era when this happened rarely and only for smaller statues – like portraits, where the limited volume eased the casting operations: their technique, means, costs and maybe also their knowledge were and proved to be inadequate to succeed in the ambitious project of making a replica of an entire, big statue of the 4th century BC using the same bronze alloy of the original. The results was a statue full of faults which could not even stand because the supporting leg – the right one – could not carry all its weight due to a big casting gap on the thigh. At the end of the assembling and welding process of head and limbs, the statue, possibly rejected by the client, had to be laid down on the store floor of the foundry. There, after a while, a family of mice must have made its burrow within the statue itself, already partially freed by its casting earth. Mice are responsible for the indentations on the peach stone 14Cdated from 110 BC to 70 AD – more probably around the average dating of 20 BC. Clearly, the casting of our statue must have occurred earlier – but not too earlier – in a lapse of time going indicatively around the middle of the 1st century BC, in the Roman late Republic Era. As for the foundry, its original cultural background must have been undoubtedly Greek, but it should be geographically linked to one of the big cities of Asia Minor, in consideration of the historical and economical arguments mentioned above5. The presence of wooden splinters and carbon remains in the right leg and armpit should be attributed to one or more restoration works, which the poor 14C dating fix around 100 AD. Maybe, after many years of abandonment, the statue had found – or was about finding – a buyer in the northern Adriatic Sea and they tried to make it stand and give it a certain stability, consolidating the better they could (at the time) the elements that more needed it. Through the imperfect casting gaps they put a pin inside the right armpit and a wooden prop in the right leg in order to reinforce and support the welding of large plugs in two areas where the gaps and the concentration of casting faults did not grant enough stability. The traces of burning and even of carbonisation found on these wooden elements are the result of the welding of those patches, which should have had supporting as well as esthetical functions. From the examination of some samples, it has been possible to assess that the larger patches were made of a bronze alloy almost identical to that of the body of the statue (fig. 7). The fact that most of them have been lost – leaving in view the embeddings on the

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See M. MICHELUCCI, Prima del naufragio, in “Apoxyomenos...”, pgs. 60-61.

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surface of the statue where they were situated – can be explained by the poor staying power of the soft solder used to applying them. Very likely the statue was shipped from Asia Minor to the northern part of the Adriatic Sea after these restoration and make-up processes. The Adriatic was the sea Romans feared most, as it can be seen in some excerpts from the poems of Catullus and Horatius, and indeed, slightly before reaching its final destination, the ship carrying our beautiful, but heavy bronze statue, run into a storm near the isle of Lo!inj and had to throw it overboard to lighten and try to escape from the wreck (fig. 11). This expedient was rather common, as it can be deduced from sources describing similar cases. No traces have been found of the ship and we cannot know if their expedient had the desired result or if the ship wrecked some miles away, under the strength of the East-North-East winds. The Apoxyomenos, however, had to wait almost 2000 year to see the light again and

Figure 11

be admired on its pedestal and undergo a new – and much more effortdemanding – restoration work (fig. 12).

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Figure 12

Is everything clear, then? Some important uncertainties still remain, where archaeometric studies cannot help. The main doubt is what the Athlete is actually doing: everybody agrees that the statue shows a winner, with the strigil in his right hand after the match, but as the strigil did not survive, since the finding of the statue of Vienna, in Ephesus in 1896, archaeologists are split in supporting two incompatible hypothesis on the represented action: some believe that the athlete is wiping the oil and sweat off his left wrist with the strigil – hence he would be an Apoxyomenos, i.e., literally “the scraping one” – while others believe that he is cleaning the inside of the strigil with his thumb after having cleaned the entire body6. Some technical tests performed in Zagreb putting a modern copy of the strigil in the right hand of the statue (fig. 13) would need further analysis, as they were made with only one standard strigil, and not with several models of different shape and size – whose existence is attested around the middle of the 4th century BC. It also seems – at least from the images that have been published 7 – that the strigil they put in the right hand was not turned in all possible positions.

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Even the two archaeologists that studied accurately the statue for the Florence exhibit have different opinion on this subject: see N. CAMBI, L’Atleta che pulisce lo strigile and V. SALADINO, L’Atleta con lo strigile, in “Apoxyomenos...”, pgs. 21-51. See “Apoxyomenos...”, fig. 27.

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Figure 13

Up to this moment, however, these tests did not provide irrefutable results, maybe also because of the slightest movements of the arms due to the fall or – like in the case of the statue of Vienna – to a restoration highly admired at the time, but today to be considered as inadequate, if not even damaging to the artefact. However, some useful elements for solving the problem come from historical sources and... logic. It is evident that this statue must have been rather famous at the time it was casted – in the 4th century BC – and in all ancient times if at least seven big and small replicas of different materials survived till our days. While ancient authors indicate two other statues of athletes wiping themselves with the strigil, i.e. Apoxyomenoi, made by Daedalus from Sicyon (still in Asia Minor!) and Polyklitus the Younger, prior to the more famous statue of Lysippus there are no indications of one or more models of statue showing athletes cleaning their strigil. Even if the ex silentio argumentation is not conclusive, considering the incompleteness and defectiveness of the ancient sources we possess, this fact is nevertheless very meaningful. Another

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consideration could be added: if our athlete cleaned the strigil with his left hand, it would have been left-handed, a less probable hypothesis. The problem is not definitely solved but strong evidence make us believe that our Athlete – as well as his twin of Vienna – is indeed an apoxyomenos, even if we will never know if it comes from an archetype of Daedalus from Sicyon or Polykleitos the Younger 8 . It was for this reason that, in spite of some authoritative opinions saying the contrary, the statue of the athlete recovered from the sea of Lo!inj got this title in his presentation to the public in the Zagreb and Florence exhibits, beautiful again after a long and hard restoration9 (fig. 14).

8 9

See M. MICHELUCCI, in “Apoxyomenos...”, p. 19. In both exhibits the exposing criteria established by Branko Sila$in were absolutely innovative and – in my opinion – brilliant: the bronze statue – immerged in a pure white and almost blinding surrounding, with no shades at all – appeared as timeless and spaceless. Breaking the traditional concepts of illumination, using a strong, diffused light coming from indefinable surfaces, the many casting imperfections and the corroded areas of the surface almost disappeared, making pop up the exceptional image as a whole. Appreciated by the public, this exposing criterion has been often (but not always!) criticised by archaeologists, professionally interested in examining the technical and execution details and the casting faults more than the statue as a whole.

14

Figure 14

15

ION BEAM TECHNIQUES FOR ANALYSIS OF CULTURAL HERITAGE OBJECTS: COLLABORATION BETWEEN THE RU!ER BO"KOVI# INSTITUTE AND THE CROATIAN CONSERVATION INSTITUTE* STJEPKO FAZINI!†, IVA BO"I#EVI!, "ELJKO PASTUOVI!, MILKO JAK$I! Division of Experimental Physics, Ru!er Bo"kovi# Institute, Bijeni$ka c. 54, Zagreb, Croatia DOMAGOJ MUDRONJA, KATARINA KUSIJANOVI!, MARIO BRAUN Croatian Conservation Institute, Gr"kovi#eva 23, Zagreb, Croatia VLADAN DESNICA Laboratory for Science and Technology in Art, Department for Conservation and Restoration, Academy of Fine Arts, Ilica 45, 10000 Zagreb, Croatia Collaboration between the Croatian Conservation Institute (CCI) and the Laboratory for Ion Beam Interactions of the Ru%er Bo&kovi' Institute (RBI) in the field of analysis of cultural heritage objects is reviewed. This collaboration is based on applications of ion beam analytical methods for characterization of inorganic pigments, alloys and other materials in paintings, statues and other objects of cultural value that are under restoration/conservation process by the CCI specialists. Elemental composition of samples is determined by using ion beam analysis techniques such as Particle Induced XRay Emission (PIXE) and Rutherford Backscattering Spectrometry (RBS). The work is performed at the ion microprobe and other end-stations installed with the RBI Tandem accelerator facility. The methodology of work will be shortly presented and illustrated by one example of recently performed work.

1. Introduction The main analytical laboratory in Croatia dedicated to the analysis of cultural heritage and art objects operates within the Croatian Conservation Institute (CCI). Scientific analysis of artistic and cultural heritage objects is organized by the CCI through their Natural Science Laboratory with the main purpose to *

†

The work presented has been partially supported by the EU FP6 RBI-AF and IAEA CRO13050 projects. Corresponding author, e-mail:[email protected].

16

enable their better restoration and/or conservation. Chemical analysis of art objects may be an essential step in estimating their authenticity, origin and age; and for selecting appropriate restoration or conservation protocol. Due to a high historic and/or artistic value of such objects, one of the most important criteria for selection of analysis techniques is its capability for non-destructive investigation. The non-destructive character in this case means that the analysis process does not alter nor modifies in any way the investigated area. For objects or samples too large or too delicate and for artifacts on which sampling is not possible/allowed one has to apply a further criterion – that of non-invasiveness. Under the non-invasive term it is understood that any sampling or dismounting of the artifact is avoided and more generally that its integrity and its environment are preserved. Furthermore, since artifacts can often exhibit extremely different material composition and structure, analytical methods allowing sensitive and multielemental characterization are highly required. The CCI natural Science Laboratory has been equipped with microscopes enabling them to perform various microscopy techniques based on investigation of objects by using visible, infrared or ultraviolet light. In addition, CCI is equipped with the X-ray imaging system and with modern portable X-ray Fluorescence Spectrometer (XRF) used for in-situ chemical analysis of surfaces. Access to ion beam micro analytical techniques is provided to CCI through already long and successful collaboration with the Laboratory of Ion Beam Interactions (LIBI) of the Rudjer Bo&kovi' Institute (RBI), where elemental composition is analyzed by using ion beam analysis (IBA) techniques, such as Particle Induced X-ray Emission (PIXE) and Rutherford Back-scattering (RBS). One of the first successful collaborations between the LIBI staff and the CCI was between 1985-86, when the RBI participated in a project named “Secret paintings of Josip Ra(i' and Miroslav Kraljevi' – analysis by physical and chemical methods”. The project goal was to perform scientific analysis of paintings done by two important Croatian painters that were active at the period from the end of the nineteenth to the beginning of the twentieth century, to identify the methods and materials used by artists, to compare them, and to present results to the general public. It included analysis by X-rays, infra-red and UV light. RBI analyzed elemental constituents of pigments on 28 paintings. Analysis of pigments was very important part of the overall analysis. The project ended up with an exhibition (that presented all the scientific work) which was held at the Modern Gallery in Zagreb, between 6th March and 6th April 1986. Since then, a continuous collaboration between LIBI and CCI exists, where LIBI provides supplementary analysis of cultural heritage objects by using ion

17

beam analytical techniques. Short overview of the analytical methods used by LIBI will be shortly presented and illustrated by one example of recently performed work. 2. Ion beam analysis at RBI Through the Laboratory for Ion Beam Interactions, the Division of Experimental Physics of the Rudjer Boskovic Institute operates and maintains the Tandem Accelerators facility that physically consists of two electrostatic accelerators, associated beam lines and measurement end-stations. The facility is used for research and applications by various clients/collaborators in a range of fields, including nuclear and atomic physics, applications in materials science and development of advanced materials, archaeology and characterisation of cultural heritage objects, etc. The basis of CCI and LIBI collaboration is in the use of ion beam analysis techniques, such as Particle Induced X-ray Emission (PIXE) and Rutherford Back-scattering (RBS) for analysis of elemental composition of samples (objects). Nuclear reaction products

Charge pulse

! " rays

Recoil nuclei

Ion beam

Transmitted particles

X-rays

Forward scattered particles

Backscattered particles Secondary electrons

TARGET Light

Figure 1. Interaction of ion beams with target materials.

When energetic ion beam (of several MeV energy) hits a target (see Figure 1), individual ions penetrate through the target material in their incident direction, gradually losing energy until they stop at certain depth, which is typically at the order of 0.1 mm (depending basically on the ion initial energy and the target material). One of the most probable processes which takes place along the path of incoming ion (proton) is its scattering with electrons. As a result of this scattering, atoms are ionized, with electrons being ejected from atoms. The ionized atom tends to return to its original state, by filling created vacancy with electrons from the outer shells. The excess energy will be given to an emitted photon (X-ray emission) or an electron (Auger electron emission).

18

The energy of the emitted X-ray depends on the atom type and allows elemental characterization when x-rays are detected with appropriate detector. This is the basis of PIXE spectroscopy1. PIXE is multi-elemental non-destructive detection method capable to measure concentrations of elements from Na to U with the sensitivity down to the ppm scale. Another processes occur in the interaction of the primary ion beam with the material in the target (see Figure 1), resulting with the emission of gamma rays, secondary electrons, nuclear reaction products, or for example backscattered primary ions. Detection of these backscattered primary ions form the basis of the Rutherford Backscattering Spectrometry (RBS)2, which is useful method for determination of elemental concentration depth profiles in thin films, and is very often performed simultaneously with PIXE. If gamma ray detector is available, then one can at the same time employ the so called Particle Induced Gamma ray Spectrometry (PIGE) which is particularly useful for detection of some light elements3. Three end-stations have been used in the analysis of cultural heritage objects. Two of these end-stations are designed for small samples that has to be analyzed in vacuum. The first one is the general purpose IBA end-station (Figure 2a). This end station is equipped with the vacuum chamber and detectors for PIXE, PIGE and RBS measurements. Samples have to be inserted in the vacuum chamber, and are limited in size to several cm in diameter. The ion beam has dimensions between 1 and 5 mm, and this determines the size of the area to be analyzed.

Figure 2. Two end-stations for small samples for analysis in vacuum. The left side (a) shows the general purpose ion beam analysis end-station, while the ion microprpbe end-station is shown on the right (b).

The second end-station is the ion microprobe (Figure 2b), which is an instrument designed to focus ion beams to micrometer dimensions. The nuclear

19

microprobe facility at RBI has been in operation since 1991 and since then significant improvements in ion beam focusing, beam intensity, and detection systems have been made4. The recent upgrade, in which quadrupole dublet has been extended to quintuplet configuration, enabled focusing of protons and heavier ions to less then one )m. Focused beam can be scanned over the sample surface, covering analysis areas of up to about 1x1 mm. Samples for analysis have to be inserted in the vacuum chamber which is seen in the centre of the Figure 2b. Inside the chamber detectors for x-rays, scattered, recoiled and transmitted particles are located. As x-ray detector a 10 mm2 silicon drift detector (SDD) is used, which can, contrary to the conventional Si(Li) detectors, work with high count rates (more than 10000 cts/s) and does not need liquid nitrogen for cooling. Samples size can range from micrometer dimensions, up to 1-2 cm. The data acquisition system SPECTOR developed at the Institute5 enables recording of all signals from detectors together with the ion beam position in the moment of a particular event. This allows display of two dimensional images of information given by a particular detector. The third end-station is dedicated for measurements on samples which cannot be exposed to vacuum and cannot be sampled, i.e. for non-invasive and non-destructive analysis of objects. This is so called in-air end station, where ion beam is extracted through thin foil in the air, and an object for analysis is exposed to the ion beam in air. It is equipped with the sample stand that allows fine XYZ sample translation and positioning, and with Si(Li) x-ray detector for PIXE measurements.

3. Example: Analysis of pigments at the ion microprobe Non-destructive IBA methods can be applied for analysis of various materials, which are of interest to conservators during their work: paintings and pigments, illuminated parchments, metals and alloys, gold and jewelry, ceramics and glass, bones (posthumous remains) and objects made of bones, transcripts, wooden objects etc. As the main application of this method is directed to the characterization of materials, i.e. qualitative and quantitative determination of elemental composition, the results may yield diverse information about the state of a certain sample/object, its elemental constituents, help to clear the provenance question and enlighten the phases of production, and finally help conservators to choose the best methods and materials for work with the artifacts. The following example is given to illustrate the use of the ion microprobe for analysis of pigments.

20

The same conventional samples of paint layers cross sections embedded in polyester resin as prepared for optical microscopy investigations can be used for the analysis using the focused proton beam from the ion microprobe, with the objective to identify paint layers. During the last decade we have analyzed hundreds of such samples in relation to different projects6,7. Figure 5 shows typical samples with several paint layers as seen by optical microscope.

Figure 5. Typical samples as prepared for Optical Microscopy are suitable for nuclear microprobe investigation. The areas showed cover 0.4x0.6 mm. Minimal size of a sample needed is several )m.

Figure 6. elemental maps of Hg, S (+Pb+Hg), Fe, Si, Pb, Cu, Ca and Al in one of the microsamples taken during restoration from one of the paintings of the polyptych originating from the church ''Gospa od $unja'' at the island of Lopud near Dubrovnik.

Figure 6 shows elemental maps of Hg, S (+Pb+Hg), Fe, Si, Pb, Cu, Ca and Al in one of the microsamples taken from one of the three restored paintings, parts of a composition originating from the church ''Gospa od $unja'' at the island of Lopud near Dubrovnik. The whole composition is attributed to the

21

painter Matej Jun(i', based on known manuscript from 1452, where it was written that four Lopud inhabitants ordered and three months later paid to master Matej Jun(i' preparation of an altar with 12 paintings8. Figure 7 shows three investigated paintings.

Figure 7. Three investigated paintings.

Twenty one microsamples have been taken and analyzed together with insitu surface analysis done by using portable XRF. As a result, a number of pigments have been identified and information about restoration activities in the past were obtained. The following pigments were found in analysed samples: white: - lead white (2PbCO3.Pb(OH)2) - gipsum (CaSO4.2H2O) - barium white (BaSO4) – 19th century red:

- cinnabar (HgS) - red ochre (Fe2O3 x nH2O) - bolus (Al2O3 x SiO2 +Fe2O3) - organic red - alizarin (Al(OH)2) - minium (Pb3O4)

- azurit (2CuCO3 x Cu(OH)2) - (CaCuSi4O10) - ultramarin (2Na2Al2Si2O6 x NaS2) brown and yellow: - Iron oxide (brown and yellow ochre) black - organic black (C) metals: - gold (Au) blue:

22

- (Cu+Zn) – in compound characteristic for 19th century. Two dimensional maps of elemental composition confirmed that paintings were over painted with several layers, and that the last layer was done in 19th century, as can be concluded from the fact that some pigments and materials discovered at the beginning of 19th century were used. High concentration of calcium and sulfur proved the usage of gypsum like filling in the base, where the presence of aluminum and silicon indicated addition of some silicates, while the high content of lead shows extensive use of lead white in combination with other pigments like azurite. References 1. S. A. E. Johansson and J. L. Campbell, PIXE: A novel technique for elemental analysis, John Wiley & Sons, New York (1988). 2. W.K. Chu, J.W. Mayer, M.A. Nicolet, Backscattering spectrometry, Academic Press, New York (1978). 3. A. Savidou, X. Aslanoglou, T. Paradellis, M. Pilakouta, Nucl. Instr. and Meth. B152, 12 (1999). 4. M. Jak&i', I.B. Radovi', M. Bogovac, V. Desnica, S. Fazini', M. Karlu&i', Z. Meduni', H. Muto, ". Pastuovi', Z. Siketi', N. Skukan, T. Tadi', Nucl. Instr. and Meth. B261, 541 (2007). 5. M. Bogovac, I. Bogdanovi', S. Fazini', M. Jak&i', L. Kukec, W. Wilhelm, Nucl. Instr. and Meth. B89, 219 (1994). 6. S. Fazini', ". Pastuovi', M. Jak&i', M. Braun, D, Krsti', D. Mudronja, Utilization of Accelerators, Proceedings of an International Conference, IAEA Proceedings Series, STI/PUB/1251, IAEA, Vienna, (2006). 7. V. Desnica, K. $kari', D. Jembrih-Simbuerger, S. Fazini', M. Jak&i', D. Mudronja, M. Pavli(i', I. Perani', M. Schreiner, Appl. Phys. A92, 19 (2008). 8. J. Belamari' et al., The Gotic Century on the Adriatic Painting in the perspective of Paolo Veneziano and his followers, Gallery Klovi'evi dvori, Zagreb, Croatia (2004).

23

STUDY BY MOBILE NON DESTRUCTIVE TESTING OF THE BRONZE STATUE OF THE “SATIRO” OF MARSALA. GIUSEPPE GUIDA, DOMENICO ARTIOLI Istituto Superiore per la Conservazione, MiBAC STEFANO RIDOLIFI and GIOVANNI E. GIGANTE Dipartimento di Energetica, Sapienza Università di Roma

The bronze statue called the “il Satiro danzante” was found underwater in the Sicily channel in the 1997. The restoration at the Istituto Centrale per il Restauro was very long and careful, assisted by diagnostics procedures in order to help the conservative choice in the consolidation of the artefact and to know the age and provenance of the statue. The results on the alloys composition and structure are reported in this paper.

Introduction The study by means of destructive and non-destructive methods of investigation of the bronze statue of the “Satiro” had been possible because it was in restoration for a long period of time in the l’Istituto Centrale per il Restauro [1]. A complete diagnostic examination of a work under restoration is a practice becoming common, with some difficulties, in the conservative restoration of very relevant works [2]. The relative high cost of diagnostics limits, instead, the use in all cases, with remarkable risks and limitations overall for the aspects concerning the monitoring and maintenance of restored work. An extended program of investigations hasn’t, in fact, the only finality of conservation, but also of a better knowledge of restored work under the point of views of its material consistency and of a more precise historical identification [2]. In the case of a work, as the Satiro, accidentally recovered in the Sicily channel (outside by an historical context to which refer, then with a provenance and more uncertain historical context) the exams oriented toward the knowledge can have a greater importance then in other cases. This is the reason because in this paper the aspects of knowledge and identification of the work under study will be discussed in more details. Among the different approaches to the study of ancient metals the use of in situ non invasive techniques is rather recent thank to the growing potentialities

24

of mobile systems of non destructive testing and to the possibility to perform metallographic exams in situ; this kind of exam allow to study the production technology and to identify the techniques used in the casting a big bronze statue [4]. The non destructive approach has been privileged, but it is not to be neglected to verify always the results with destructive tests, making microsapling in hinder parts of the artifact. In the case of the Satiro the main open arcaeometric problems are: a) the age of the artefacts, b) its provenance, c) the casting techniques and the used surface treatments. 1. Measuring techniques and experimental apparatus A short description of experimental methods and apparatus is given in the next paragraphs. 1.1. In Field EDXRF spectrometer The Field Portable Energy Dispersive X-Ray Fluorescence (FP-EDXRF) technique is based on excitation of samples with X-rays and measurements of the energy of the secondary X-rays emitted by the samples themselves. The energy of secondary (also known as characteristic) X-rays depends on the chemical elements present in the sample being examined while the intensity of the energy is proportional to the abundance of the element under scrutiny. These surveys may be carried out prior or during the restoration work; however, as the methodology is totally non-invasive, it may be applied for purely informative purposes, regardless of intervention. The penetration of X-rays varies from a mere few (as in the case of gold) to several hundred microns (as in the case of light-weight matrix elements, for example those containing relevant amounts of organic compounds). The EDXRF examination is capable of detecting the composition of a metal alloy, in fact the high atomic numbers and the density of metal alloy facilitate the production of fluorescent X-rays of enough energy to be detected, even using a low intensity sources. The fluorescent lines emitted by all elements compounding the alloy appear within the spectrum, whereas low atomic-number elements are absent or minoritary in the matrix. A typical EDXRF-system is composed of three parts: a) an X-ray tube; b) an X-ray detector with electronics; c) an acquisition system with a multichannel analyser. The X-ray tube works at 30 kV and 0,1 mA. It is a light (air cooled) tube (less than 2 Kg of weight). The detector used a Silicon Drift Detector ( SDD) detector having a energy resolution of 139 eV at 6,4 keV. The detector is cooled with a Peltier build in circuit [5].

25

1.2. Metallography Metallography is the technique of preparing a metal surface for analysis by grinding, polishing, and etching to reveal microstructual constituents. After preparation, the sample can easily be analyzed using optical or electron microscopy. A skilled technician is able to identify alloys and predict material properties, as well as processing conditions and corrosion process due to the exposition to the different environments [6]. Metallographic specimens were "mounted" using a hot compression thermosetting epoxy resin. Mounting a specimen provides a safe and ergonomic way to hold a sample during the grinding and polishing operations. After mounting, the specimen is wet grounded to reveal the surface of the metal. The specimen is successively grounded with finer and finer grades of silicon carbide paper to remove damage from sectioning and then from each grinding step. After grinding the specimen was polished with a slurry of alumina, silica, or diamond on a napless cloth to produce a scratch-free mirror finish, free from smear, drag, or pull-outs and with minimal deformation remaining from the preparation process. After polishing, certain microstructural constituents can be seen with the microscope, e.g., inclusions and nitrides. Finally in order to reveal crystal structure (apart the non-cubic ones) were used suitable chemical or electrolytic etchant. 2. Results and discussion The starting point in the discussion on the obtained results is that, as is very common in the classic roman period, the statue is built soldering together different pieces. A careful examination during the restoration allow us to establish that a) head, b) chest, c) two legs, d) two arms are joint together by welding. The strong corrosion of the surface forbids the non destructive analysis of the alloys directly on the artefact after a scratching of the patina, that is a common practice on ancient bronzes that do not showing yet a thick degree of corrosion, as it is in the case of Satiro. It was chosen then to do few samples, however doing a mapping of the artefact surface with the aim to put in evidence superficial degradation phenomena of the alloy. 2.1. Alloys composition In table I are shown the results obtained on the samples, obviously done on the different pieces compounding the Satiro, in figure 3 are shown the withdrawals points. Taking only into account the results to be refer to the six pieces the first observation is that the alloys shown a similar composition, all featuring a high

26

lead concentration (14-21%) which, as will be confirmed following by the metallography, undergo a globular segregation. The head is constituted by high tin (11%) concentration alloy, in comparison with the other parts (4-6%), probably an intentional choice to obtain a better fluidity of the alloy. After all the hair alloy look similar, characterised only by lower lead concentration probably a liquefaction due to different behaviour during the melting and solidification phases. The first hair sample belongs to a piece melted apart. The lower iron concentration, the only marker allowing us to assess the purity of the row materials used, may suggest a greater care in the material selection, compared to that done for the other parts. The high artistic quality of the head, requiring a grater care, could therefore find verification. Table 1. Results of the EDXRF analysis on withdraw samples of the alloy from the Satiro. Position of the withdrawals head (rear inner folding in the right)

Cu

Sn

Pb

Fe

68,5

11,2

20,4

0,5

hair (inner side of the head)

76,6

9,8

13,6

0,4

hair (big piece detached)

73,8

9,3

16,9

0,4

left thigh (near the edge)

73,9

4,4

21,0

0,7

right thigh (external side )

70,4

6,4

21,7

1,4

left arm (inner side)

70,7

12,9

15,4

1,0

left arm (inner side)

72,2

12,7

14,1

1,0

right arm (external side)

69,1

8,7

21,1

1,1

right arm (inner side)

72,7

5,2

20,1

2,1

left leg (external side)

73,3

9,6

16,3

0,7

left arm (on the soldering)

49,5

7,4

42,5

0,6

right arm (on the soldering)

69,1

5,5

24,5

0,9

The sample taken from the welding show an increase of lead concentration, very evident in one of the two samples, pointing out the use of a copper alloy with a higher lead concentration. The results of the metallographic study of the samples taken by the head (figure 1), the left arm and the left thigh clearly showed a crystalline microstructure constitute by a dendritic array tending to a polygonal shape with the evidence of sliding planes. All the samples show a much corroded surface; this corrosion goes deep into being of an inter-dendritic type. In the case of the head it is in the interval 300-500 micron and for the left arm reach the 800 micron. Lead rounded globes of variable size and inclusions of different kind are always present. Table II shows the results of the analysis of the alloys obtained on the three metallographic samples; they are quite different from those on the withdraw samples. The superficial treatment of this sample could alter the results, for ex-

27

ample for the presence of lead globe. The obtained result confirms however that the alloys of the Satiro have a high lead concentration and a tin one in the normal range for an artistic bronze.

Figure 1. Images of metallographic sample taken from the head, right 100 !, left 200!. Table II . Results of EDXRF analysis on the three metallographic samples. Withdrawal position for metallography

Cu

Sn

Pb

Fe

Head (withdrawal from the nape)

80,7

8,2

10,9

0,2

Left arm

70,5

9,4

20,2

0,2

Left leg

71

8,5

20,5

0,2

Figure 2 . Left an example of corrosion phenomenon (green patina), left an example of sea origin concretion.

Figure 3. Position of some measuring points on the left leg of the Satiro.

28

2.2. Results of the superficial mapping with a EDXRF spectrometer With the aim to characterise the different corrosion phenomena on the Satiro surface and, maybe, identify the hexogen material adhering to it, (figure 2), a systematic surface mapping was carried out. The points were chosen using the visible alterations and their colour with the help of the restorers. In the three following figures (figure 3-5) the position of 26 points is shown and in table III there is a short description of their visual aspect.

Figure 4. Position of some measuring point on the chest, head and back of the Satiro There are several and useful results of the mapping that are not possible to include in this discussion. It was possible to identify particular alteration processes, such as that of point 18 (figure 6) in which the presence of iron and manganese allow to attribute the black colour to a digenesis phenomenon with minerals of the sandy floor.

29

Figure 5. Position of some measuring points on the hip and thigh of the Satiro. 3500

7000 Counts/channel

3000 2000 1000

Sn K!

Counts/channel

4000

Fe K !

Pb L"

2000

5000

Pb L" Pb L!

Pb L!

2500

6000

Cu K!

Mn K!

8000

Cu K !

Mn K!

3000

0 0

2

4

6

8 10 12 14 16 18 20 22 24 26 28 30 Energy (keV)

1500

Fe K !

1000

Sn K!

Sr K !

Cu K" Ni K !

V K!

Pb M

Sn K"

Zn K !

Fe K"

Ca K !

500

0 0

2

4

6

8

10

12

14

16

18

20

22

24

26

28

30

Energy (keV)

Figure 6. Two spectra of the left leg, point 18 colour dusty dark-black,

References 1. You can see a video in WWW pages at: http://www.youtube.com/ watch?v=aKiwY1pvEsU

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2. G.E. Gigante, S. Ridolfi , G. Visco , G. Guida, “Appraisal of the new approach to the archaeometric study of ancient metal artifacts by the use of movable EDXRF equipments”, proceedings of della “International Conference on Araechaeometallurgy in Europe, II 293-302 ISBN 88-85298-50-8 (2003). 3. R.Cesareo, G. E. Gigante, A.Castellano, J.S. Iwanckyk, “Portable Systems for Energy Dispersive X-Ray Fluorescence Analysis”, Encyclopaedia of Analytical Chemistry, R. A. Meyers Ed, ed. John Wiley & sons, 1332713338 (2000). 4. R. Cesareo, G.E. Gigante, P. Canegallo, A.Castellano, J.S. Iwanczyk and A. Dabrowski Nuclear Instruments and Methods in Physics Research B. 380, 440-445, (1996). 5. G. E. Gigante., R. Cesareo, Radiation Physics and Chemistry, 51(4), 689700, (1998). 6. G.Giardino, G.E. Gigante, G. Guida and R. Mazzeo, Sciences of Conservation & Archaeology, Shanghais, 10, 58-64 (1998). Table III – Description of measuring points in the mapping on the Satiro surface N°

Visual identification

Short description of obtained results

1 2 3 5 6 7 8 9 10

Near-white clear dusty green Green Near-white clear dusty green Nearly unpatinated iron grey Clear dusty green Blue-grey Grey-brown (clean spot) Clear brown Thick emerald green

11 12 13 14

Thick average green Dark glossy green Blue-grey (below calcareous concretions) Olive-green

Lead remarkable superficial enrichment Lead remarkable superficial enrichment Lead and zinc superficial enrichment Lead remarkable superficial enrichment Lead, iron and tin superficial enrichment Lead remarkable superficial enrichment Lead remarkable superficial enrichment, iron and vanadium Iron and vanadium remarkable superficial enrichment Lead, superficial enrichment, strontium, calcium, potassium and vanadium Lead, superficial enrichment, iron, manganese and vanadium Lead superficial enrichment Lead superficial enrichment

16 17 18

Inner point Dark-brown Dusty dark-black

19 20 21 22 23

Remedial plug Basin welding Cleaned area Black point on the chin Grey-brown point on thecheek Basin welding on the neck Outer spot of the welding Eye

24 25 26

Lead superficial enrichment, calcium, manganese, iron and vanadium Lead, zinc, tin remarkable superficial enrichment Calcium, iron and strontium Lead remarkable superficial enrichment, calcium, potassium, manganese, iron, zinc and strontium Calcium, potassium, iron and strontium Lead remarkable superficial enrichment Lead superficial enrichment, vanadium Lead remarkable superficial enrichment, iron enrichment Lead and iron remarkable superficial enrichment, calcium, vanadium, strontium Lead and iron remarkable superficial enrichment, zinc Lead and iron remarkable superficial enrichment, zinc Calcium, iron, strontium

31

ARCHAEOMETRIC MEASUREMENTS WITH PIXE IN SLOVENIA !. "MIT University of Ljubljana, Faculty of Mathematics and Physics, Jadranska 19, SI-1000 Ljubljana, Slovenia, and Jo!ef Stefan Institute, Jamova 39, POB 3000, SI-1001 Ljubljana, Slovenia The in-air proton beam of the tandem accelerator of the Jo#ef Stefan Institute is used for systematic investigation of the archaeological artifacts and objects of art. The review guides through the results obtained by the PIXE and PIGE methods on the investigation of medieval glass, metal objects of the Roman and medieval period, numismatics and painting pigments. The differential PIXE method for the evaluation of concentration profiles is briefly introduced.

1. IBA methods Ion beam analytical provides efficient methods for the analysis of cultural heritage objects. Irradiation with a particle beam produces nearly negligible irradiation damage, and the techniques based on the particle beam in the air allow simple handling of the objects irrespective of their size. Simultaneous measurements with different types of detectors enable a large range of elements that can be analyzed simultaneously: the method of proton induced X-rays (PIXE) can detect elements from about aluminum to uranium; the characteristic K-shell X-ray lines are used for the elements up to about tin, and the L-shell Xray lines for heavier elements. The limitation at the lightest elements is due to the X-ray absorption in the air and the inactive parts of the detector. Using helium flush in the interacting region and a thin-window X-ray detector, the light elements up to sodium can easily be detected, reaching oxygen and carbon with special experimental set-ups. However, the excited X-rays in this case originate from the very surface layer about one micrometer thick, which could easily be altered by corrosion and other chemical effect. It is then more convenient to analyze the light elements by nuclear reaction analysis; in order to overcome the Coulomb barrier of the nucleus, these have to be performed by projectiles of higher energies that penetrate deeper into the target. The method of proton-induced gamma-ray emission (PIGE) is based on the detection of

32

gamma rays excited by inelastic proton scattering or in resonant reactions via the compound nucleus. The elements between sodium and silicon emit gamma rays of energies between a few 100 keV and 2 MeV, which can efficiently be measured by intrinsic germanium detectors. The lightest elements emit more energetic gamma rays of a few MeV energy; the scintillation detectors provide a better counting efficiency in this energy range. Though all ion beam methods are limited to the sample surface (which requires special care for determining the bulk concentrations), they provide unique possibilities for studies of the surface structures of the objects. Rutherford backscattering analysis (RBS) can reveal the surface layers of heavy elements, while the light elements (notably hydrogen) can be determined by elastic knock-out (or recoil) by heavier projectiles (ERDA); both methods can be performed by an external particle beam in helium atmosphere. Depth profiling can also be made by resonant nuclear reactions. The deepest concentration profiles can be reached by differential measurement, i.e. by varying the projectile energy or the incidence angle, thus reaching different depths of the target. First archaeometric measurements at the Jo#ef Stefan Institute were performed occasionally, using an old Van the Graaff accelerator and a vacuum measuring chamber; they include an analysis of a series of Celtic coins [1] and studies of usewear layers on Mesolithic stone tools [2]; microbeam techniques were also used, in laboratories abroad [3]. In 1997, a new 2 MV Tandetron accelerator became operative at the Institute. Archaeometry was among the new applications, but since then in collaboration with the National Museum of Slovenia. The joint research is funded in various forms by the Slovenian Ministry of Science. Informal collaboration also involves other institutions, including the National Gallery of Slovenia, Slovenian Academy of Sciences and the Faculty of Arts. The experimental techniques involve mainly the PIXE-PIGE method in air, but also the micro beam was used; presently the RBS/ERDA techniques are used in helium atmosphere. The materials studied are glass, metals and painting pigments. The research politics is to perform measurements that would help answering some historic questions; though sporadic service measurements asked by the museum conservators are also carried out. 2.

Analysis of glass and ceramic materials

Excavations in Ljubljana provided a large amount of glass, characterized typologically as glass in the Venetian manner (à façon de Venise) and dated to the 15th and 16th century [4]. As historic records point to several glassworks operating in Ljubljana in that period, it was certainly challenging to study the glass chemical composition and distinguish the possible domestic production from the Venetian import. As the museum preferred measurements to be done

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without sampling, the analysis with ion beams was the only choice. The measurements involved about 370 glass fragments. Initially we planned to analyze the glass only PIXE [5]. The statistical treatment of a limited number of chemical elements clearly showed that the glasses of Ljubljana can be divided into two groups; different groups were obtained for the control groups of lateRoman glass and the potassium-based forest glass. However, as the contents of sodium, magnesium and aluminum are quite important for the glass characterization, we have further analyzed glass by PIGE for these light elements [6]. The results confirmed the classification of glasses from Ljubljana into two groups. At the same time we also analyzed a few examples of glass colored plates, undoubtedly imported, which appeared markedly different from the glass of Ljubljana. Further interpretation of our data was done in collaboration with prof. Koen Janssens of the University of Antwerp, who with his group analyzed a large amount of façon de Venise glass from Antwerp, Northern Europe and Italy. Comparing all these analyses together it was possible to show that the glasses of Ljubljana split into two groups due to two different types of the flux [7]. The same types of flux were identified in the original white glass (vitrum blanchum) from Venice and also among the Antwerp glass. The more precious glass, cristallo, was not produced in Ljubljana, as its production was monopolized, but it occurred in Antwerp, possibly due to the weaker political influence of Venice there. We subsequently analyzed a series of glasses from Celje, another Slovenian town, and identified the same types of the flux. This finding indicates that the glassworks in the 16th century Slovenia used the same type of flux as the Venetian glassworks, and that they probably imported it from Venice directly. The glassworks imported either flux and melted the glass themselves, or they imported raw glass as semi product. The answer to this question may be sought from the elements characteristic for the siliceous component of the glass, as the domestic glassworks probably exploited the local sources. The respective analytical method should have sensitivity in the ng/g region, which is inaccessible by ion beam methods. We have therefore performed measurements on a small series of glasses from Ljubljana and Venice, using the laser-ablation mass spectrometry (LA ICP MS) at the University of Warsaw; the glasses had to be sampled. Among the inspected features, the Zr-Hf correlations and the contents of rare-earth elements appeared insignificant for the two groups of glasses. Among the Coryell-type classification, which relies on different chemical properties of rare-earth elements, we found a promising grouping inspecting the ratio of Nd/Dy as a function of Zr [8]. A small group containing no glasses from Venice suggests a local source of silica.

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We analyzed a limited series of other types of glass, the early industrial glass from Slovenia and Art Nouveau glass from the museum funds. The current investigation involves glass from the archaeological site Gradi$%e above Ba$elj near Kranj; it had two population phases dated to the Late Antiquity and the Carolingian period in the 9th century. A large fraction of the glass fragments can be dated by the archaeological method; they coincide with the transition period when the flux made of plant-ash replaced the soda flux common in Roman glassmaking. The measurements showed only two small beads made with the pant ash; the rest being soda-type glass. This indicates glass of the Roman tradition prevailed in the area well into the 9th century. The analysis of ceramic materials includes the cream-colored earthenware produced in Slovenia in the early 19th century. The current work involves analysis of objects and fragments from the collections of the National Museum of Slovenia; terrain work with identification of the clay sources is also planned. The analysis of ceramic objects imposes two problems: the objects are covered by a glaze, so the bulk material can only be reached in spots where the objects were broken or excessively worn out. The clay material is rather pure, and the characteristic trace elements cannot be measured by the PIXE method. The classification, pointing to particular known workshops was attained according to the relative composition of light elements in the clay; their concentrations were determined by the combined PIXE-PIGE method. 3. Metals Analysis of metal alloys is one of the simplest PIXE applications. The calculation of concentrations can rely on setting the sum of all concentrations to unity, which is feasible if all elements in the object are detected. This condition is fulfilled in archaeological alloys that do not contain light metals, such as aluminum and beryllium. Since our early work [1] we developed a computer code that is based on a fast integration algorithm and incorporates secondary fluorescence effects [9]. Systematic studies of metals started with analysis of the Roman military equipment. The investigated objects included fragments of sword scabbards, daggers, belt plates, strap ends, plaques and medallions. Analysis of a gladius from the river Ljubljanica dated to the 1st c. BC showed brass scabbard fittings [10]. This finding stimulated dr. Janka Isteni% to investigate further the early spread of brass in the Roman world, specifically in the south-eastern Alpine region. Her idea was to analyze a series of well dated brooches and detect the appearance of brass [11]. The brooches were of the types Palmettenfibeln, Schüsselfibeln, Nauheim, Almgren 65, Alesia, Jezerine I and II. Brass started to

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appear in the Almgren 65 and became prevalent at the Alesia type brooches; bronze was again partly applied for the Jezerine brooches, probably due to the production in local workshops with a limited access to brass. This places beginning of the brass use to around 60 BC [12]. This is earlier than minting of brass coins; the first issues appeared in 46/45 BC, though a common use of brass for dupondii and sestertii was introduced in the reign of Augustus. Brass was an attractive material for the military equipment due to its golden appearance. The Romans produced brass by the cementation technique, melting together finely divided copper, carbon and zinc ore; this procedure was required, as the metal zinc would evaporate before the copper melts. The highest zinc concentrations obtained by this procedure were about 28%; the highest values we detected were about 22%, though most of the objects exhibited zinc concentrations of about 15-20% (Fig. 1). Objects of smaller zinc concentrations were also found, which indicates that the brass objects were recycled, occasionally with bronze. The corrosion processes can remove zinc from the surface; for reliable measurements it was necessary to gently polish the investigated area in a size of a few mm2. 0.20 h=0.5% n=29

0.15 den sity 0.10 0.05 0.00

0

5

10

15

Zn (%)

20

25

Figure 1. Statistical distribution of zinc in the Alesia-type brooches.

Among the other interesting finds from the river Ljubljanica we analyzed silver object from the Hoard of Vrhnika [13] (they were made of high-grade silver gilded in the sunken parts of the relief) and a medallion with the portrait of Augustus [14]. The medallion was made of a cheap lead-tin alloy with a low melting point, but it was silvered at the front side and fixed to the substrate by soldering. The solders were similar as used today, made of the tin-lead alloy. From the iconography, the medallion can be connected with the Augustus’ victory over Parts [14]. Upon requests of the museum conservators we analyzed a few daggers ornamented with silver and brass wire and niello. Identification of these materials was necessary for selection of the cleaning procedure. A heavy clay pot was discovered in the Roman site of Drnovo in 2003. Non-destructive X-ray and neutron radiographic investigations revealed that the pot contained a hidden treasure composed of coins of several objects. After the

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pot was open, two massive silver brooches (dated to the 3rd c. AD) were investigated by PIXE [15]. The surface composition showed that silver (7580%) was diluted with brass. Two grey spot were observed in the inner part of the bow. The analysis of these points showed a mixture of silver and white bronze, i.e. an alloy of copper, lead and a high amount of tin. This indicated that the core of the brooches was made of bronze which was plated by a thick silver layer. Corrosion layers are absent on the objects made of precious metals, which then represent ideal targets for PIXE analysis. However, gold objects of historical importance are rare and the transportation to the lab imposes certain responsibility on museum curators. We analyzed a Roman gold brooch that was found on the Alpine pass of Kranjski Rak [16]; it is one of the pair, the other being kept in Vienna. The analysis showed that the brooch was made of a rather pure gold, including the needle (now broken), which means that the brooch was made for votive purposes rather than for wear. One may conjecture that the needle made of a mechanically more resistant gold alloy would not break off. The other series of objects was from the Carolingian period – it involved the inventory from the grave 355 at the castle of Ptuj. The grave contained several silver and gold objects, the latter being a pair of earrings and a ring. The composition of the earrings was found completely different from that of the ring; it was tracked that one earring had been repaired in the past, replacing the hook with a new one of a less fine gold. The ring, originally made for a male finger, showed an inhomogeneous mixture of gold and silver. This is characteristic of electrum, and points to manufacture in the local workshops, probably in Moravia according to the stylistic analysis [16]. Non-destructive properties of IBA methods make them an attractive tool for investigations in numismatics, but the analysis involves the surface region of the coins only, about 10 µm thick. We realized this limitation during our early study of Celtic coins [1] where we made a cross scan of the coins cut to half; the coin cores were made of a less noble copper-silver alloy, probably result of the melting and cooling process of the alloy. If cuts of the coins are available, PIXE can be used to determine the bulk composition in combination with other methods, like EDS in electron microscope [17]. In spite of the limitations to the surface analysis, an interesting study was made on the silver coins struck in Slovenian mints in the period of 12th-14th centuries [18]. The coins were made of thin silver sheet, so the concentration gradients are small. The coins were mostly primary strikes and their composition reflects that of the ore. Gold and bismuth appeared as the discriminating elements and we were able to characterize the coins as being gold-type or bismuth-type. A large fraction of bismuth-type coins was struck in the mints of Carinthia and in the south-eastern part of modern

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Slovenia, which bordered to the Hungarian kingdom at that period. As silver mines were predominantly concentrated in Carinthia, this indicates a commercial flow of the Carinthian silver to the eastern mints and further to the Hungarian kingdom. These relations were stopped by the incursions of Mongolians after 1240, bringing the Slovenian mints do decline. 4. Pigments Proton beam in the air can successfully be applied for analysis of the paintings, since their dimensions usually do not fit to any measuring chamber. The measurements were performed by different standards of accuracy, as sometimes the detection of a few characteristic lines is sufficient for the pigment identification. For the high precision measurements we controlled the size of the air gap between the exit window and painting, as the argon signal from the air was used for normalization. The identification of the pigments was done systematically for the works of the Master HGG (Hans Georg Geiger) on occasion of the exhibition in the National Gallery [19]. The pigments identified were minium, red ochre and vermilion (cinnabar) for red, azurite for blue, massicot and yellow ochre for yellow, different copper-based greens (malachite, verdigris, copper resin), green earth, smalt and umbra black. All pigments were amply mixed with lead white. One painting contained traces of copper in every pigment, probably used as a desiccative. The analysis pointed out that some paintings ascribed to the Master HGG were very likely not his original works. Pigments were also identified in the textiles [20], obtaining additional information on composition of the fibers (vegetal or protein). A pilot study was made about the blue pigment used on the medieval manuscripts. Systematic measurements, extending during several recent years, were performed on the works of Slovenian impressionists. Evaluation of the results is still under way and was published only preliminary [21]. The impressionists used a variety of new pigments, which became available from the rapid development of chemistry at the turn of the 19th-20th centuries. For example, the lead white was gradually replaced by other white pigments, such as for example zinc white. 5. Differential measurements The analyzed target depth depends on the projectile energy. Varying the impact energy we can reach different depths of the target, and by proper numerical procedure we can evaluate the concentration profiles of certain elements. As the ionization cross sections vary rapidly with proton energy, the strongest

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contribution to the X-ray yields is from the very target surface, making the contributions from the inner parts of the target minute. The numerical procedures are then rather sensitive to small variations of the input data, and special procedures are required to stabilize them. We developed a stable algorithm replacing the matrix inversion by the least squares procedure [22]. The method is based on slicing the target into layers of constant elemental concentrations. The division points are selected according to the mean production depths of X-rays in the target. Plated metal targets represent the simplest application of the method. Some examples are shown in [9, 23], but a systematic study of tinned, silvered and gilded objects from the Roman and Early Medieval period is presented in [24]. The thickness of the plated layers was measured for the tinned and gilded objects, while the plated silver was too thick for penetration of 2.5 MeV protons. The gilding technique was identified as fire gilding according to the detected profiles of mercury. Paint layers can be profiled as well, though the task is more complicated due to the contents of light elements that are invisible by X-rays. The information on light elements has to be supplied independently; normally we specify the chemical compound to which the metal ions are bound. A specific example are frescoes, as their matrix of limestone can be monitored through calcium X-rays. We analyzed a test fresco prepared of known mineral pigments and a series of historic fresco fragments. These measurements also enabled us to study two different normalization procedures, based on setting the sum of all concentrations to unity and by measuring the incident proton numbers. For profiling of the oil paintings, the proton number has to be measured, as the pigments are embedded in an organic matrix. We studied the concentration profiles of the impressionist paintings, as it is known that their techniques applied thick pigment layers, often supported by pigment extenders [21]. The deduced profiles showed abundant mixing of the pigments with lead and zinc white. We were also able to resolve the pigments of the signature of Rihard Jakopi% from the background [25]. References 1. 2.

!. "mit, P. Kos, Elemental analysis of Celtic coins, Nucl. Instr. and Meth. B 3, 416-418 (1984). !. "mit, S. Petru, G. Grime, T. Vidmar, M. Budnar, B. Zorko, M. Ravnikar, Usewear-induced deposition on prehistoric flint tools, Nucl. Instr. and Meth. B 140, 209-216 (1998).

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3. 4. 5.

6. 7. 8. 9. 10. 11. 12.

13. 14. 15. 16. 17.

!. "mit, G. Grime, S. Petru, I. Rajta, Microdistribution and composition of usewear polish on prehistoric stone tools, Nucl. Instr. and Meth. B 150, 565-570 (1999). M. Kos, M. !vanut, Glass Factories in Ljubljana in the 16th Century and their Products, National Museum, Ljubljana 1994; M. Kos, 15th and 16th Century Glass, National Museum of Slovenia, Ljubljana 2007. !. "mit, P. Pelicon, G. Vidmar, B. Zorko, M. Budnar, G. Demortier, B. Gratuze, S. "turm, M. Ne%emer, P. Kump, M. Kos, Analysis of medieval glass by X-ray spectrometric methods, Nucl. Instr. and Meth. B 161-163, 718-723 (2000). !. "mit, P. Pelicon, M. Holc, M. Kos, PIXE/PIGE characterization of medieval glass, Nucl. Instr. and Meth. B 189, 344-349 (2002). !. "mit, K. Janssens, O. Schalm and M. Kos, Spread of façon-de-Venise glassmaking through central and western Europe, Nucl. Instr. and Meth. B 213, 717-722 (2004). !. "mit, K. Janssens, E. Bulska, B. Wagner, M. Kos, I. Lazar, Trace element fingerprinting of façon-de-Venise glass, Nucl. Instr. and Meth. B 239, 94-99 (2005). !. "mit, P. Pelicon, J. Sim%i%, J. Isteni%, Metal analysis with PIXE : the case Roman military equipment, Nucl. Instr. and Meth. B 239, 27-34 (2005). !. "mit, P. Pelicon, Analysis of copper-alloy fitments on a Roman gladius from the river Ljubljanica. Arheol. vestn. 51, 183-187 (2000). !. "mit, J. Isteni%, V. Gerdun, Z. Mili&, A. Mladenovi%, Archaeometric analysis of Alesia group brooches from sites in Slovenia. Arheol. vestn. 56, 213-233 (2005). J. Isteni%, !. "mit, The beginning of the use of brass in Europe with particular reference to the southeastern Alpine region. In: S. La Niece, D. Hook, P.T. Craddock (Eds.), Metals and mines: studies in archaeometallurgy: selected papers from the conference Metallurgy: A Touchstone for Cross-cultural Interaction held at the British Museum 28 30 April 2005 to celebrate the career of Paul Craddock during his 40 years at the British Museum, British Museum, London 2007, p. 140-147. J. Isteni%, The early Roman "Hoard of Vrhnika": a collection of finds from the river Ljubljanica. Arheol. vestn. 54, 281-298 (2003). J. Isteni%, Kleine Mitteilungen: A uniface medallion with a portrait of Augustus from the River Ljubljanica (Slovenia). Germania (Mainz) 81, 273-276 (2003). !. "mit, Analysis of a pair of silver fibulae. In: A. Mi$kec, M. Pflaum (Eds.), Buried Treasure / The Coin Hoard from Drnovo, National Museum of Slovenia, Ljubljana 2007, p. 76-79 !. "mit, M. Budnar, P. Pelicon, B. Zorko, T. Knific, J. Isteni%, N. Trampu#Orel, G. Demortier, Analyses of gold artifacts from Slovenia, Nucl. Instr. and Meth. B 161-163, 753-757 (2000). N. Civici, S. Gjongecaj, F. Stamati, T. Dilo, E. Pavlidou, E.K. Polychroniades, !. "mit, Compositional study of IIIrd century BC silver

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18. 19. 20. 21.

22. 23. 24. 25.

coins from Kreshpan hoard (Albania) using EDXRF spectrometry, Nucl. Instr. and Meth. B 258, 414-420 (2007). !. "mit, A. "emrov, Early medieval coinage in the territory of Slovenia, Nucl. Instr. and Meth. B 252, 290-298 (2006). I. Nemec, P. Bohanec, !. "mit, in T. Tr%ek-Pe%ak (Ed.), Conserving and Restoring the Works of Art of Master HGG, National Gallery of Slovenia, Ljubljana 2004, p. 36-40. !. "mit, Analysis of the textile fragments by the PIXE method, Diana 10, 147-148 (2004/2005). K. Kavkler, I. Nemec, A. Smrekar, !. "mit, T. Tr%ek-Pe%ak, Investigation of the Slovenian impressionist paintings by the differential PIXE method, in G. Arun (Ed.), Studies on Historical Heritage 2007, Yildiz Technical University, Antalya 2007, p. 305-312. !. "mit, M. Holc, Differential PIXE measurements of thin metal layers, Nucl. Instr. and Meth. B 219-220, 524-529 (2004). !. "mit, Recent developments of material analysis with PIXE, Nucl. Instr. and Meth. B 240, 258-264 (2005). !. "mit, J. Isteni%, T. Knific, Plating of archaeological metallic objects studies by differential PIXE, Nucl. Instr. and Meth. B 266, 2329-2333 (2008). !. "mit, M. Ur$i%, P. Pelicon, T. Tr%ek-Pe%ak, B. "eme, A. Smrekar, I. Langus, I. Nemec, K. Kavkler, Concentration profiles in paint layers studied by differential PIXE, Nucl. Instr. and Meth. B 266, 2047-2059 (2008).

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IN SITU CHEMICAL COMPOSITION ANALYSIS OF CULTURAL HERITAGE OBJECTS USING PORTABLE X-RAY FLUORESCENCE SPECTROMETRY D. WEGRZYNEK1, 2, E. CHINEA-CANO1, A. MARKOWICZ1, 2, S. BAMFORD1, G. BUZANICH3, P. WOBRAUSCHEK3, CH. STRELI3, M. GRIESSER4, K. UHLIR4, A. MENDOZA-CUEVAS5 1 International Atomic Energy Agency, Department of Nuclear Sciences and Applications , A-1400 Vienna, Austria, e-mail: [email protected], fax: +43 1 260028222 2 Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, 30-059 Krakow, Poland 3 Vienna University of Technology, Atomic Institute of the Austrian Universities, Stadionallee 2, A-1020 Vienna, Austria; 4 Museum of Fine Arts, Burgring 5, A- 1010 Vienna, Austria 5 Archaeometric Laboratory, Conservation and Restoration Cabinet, Havana's Historian Office, Havana, Cuba X-ray emission techniques play important role in the cultural heritage area. They provide information about chemical composition of an object upon bombardment of its surface with electrons, ions, or electromagnetic radiation. Their useful features include nondestructiveness, multielemental capability, and high sensitivity for inorganic components. Especially widely used is the X-ray fluorescence technique. It utilizes electromagnetic radiation generated by X-ray tubes or radioisotope sources. X-ray fluorescence equipment is relatively simple as compared to the charged particle-based spectrometers which are combined with scanning electron microscope or ion beam accelerator. X-ray fluorescence technique can be easily adapted for in situ measurements. A portable X-ray fluorescence spectrometer has been constructed utilizing commercially available, ready made components. The construction details of the spectrometer and examples of its application are given. The key features of the portable system are the use of polycapillary X-ray optics and a vacuum chamber attachment to enhance detection of low atomic number elements such as Mg, Al, Si, P, S, and Cl. The spectrometer was applied for chemical composition analysis of archaeological artifacts and works of arts from the collections of the Museum of Fine Arts (Kunsthistorisches Museum), Vienna, Austria. The investigated objects included ancient bronzes, coins, samples of pigments, and famous goldsmith work “Saliera” by Benvenuto Cellini (1500-1571). This work highlights also other projects related to the applications of nuclear analytical techniques in support of study and preservation of cultural heritage objects supported by the International Atomic Energy Agency and carried out in the Agency’s Member States.

Keywords: X-ray fluorescence, cultural heritage, non-destructive analysis, in situ.

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1. INTRODUCTION Elemental analysis of archaeological artifacts and cultural heritage objects can help to reveal ancient material usage, technology of preparation, identification of provenance and in some cases, can be used as an indirect dating tool. A highly valuable result of elemental fingerprinting can help identification of forgery by the detection of anachronistic materials. X-ray fluorescence (XRF) technique is of particular interest for archaeologists because of its multi-elemental capability, generally high level of reliability and most important, being non-destructive and portable [1-3]. Valuable artifacts in many cases have irregular shapes and are fragile making it sometimes a challenge to preserve their integrity during analysis. Over the past years, XRF has been successfully developed to meet the requirements. XRF is now widely accepted and routinely applied by researchers in cultural heritage studies and restorations. In order to support study of cultural heritage objects, a dedicated (trans)portable XRF spectrometer has been designed and manufactured in the IAEA Seibersdorf Laboratories. The spectrometer was applied for chemical composition analysis of bronze samples and pigments as well as for provenancing of works of arts in the Museum of Fine Arts (KHM – Kunsthistorisches Museum) in Vienna [4-5].

2. EXPERIMENTAL A portable X-ray fluorescence spectrometer was used for chemical composition analysis of archaeological artifacts and works of arts. The spectrometer was designed and manufactured in the IAEA Seibersdorf Laboratories in collaboration with the Atomic Institute of the Austrian Universities, Vienna University of Technology. The overall view of the spectrometer, positioned in the front of a modern painting, is shown in Fig. 1. The instrument utilizes ready-made components which include a lowpower, Pd-anode X-ray tube, high voltage power supply, thermoelectrically cooled X-ray detector, signal processing electronics, X-ray collimator, polycapillary focusing optics, two laser pointers, miniature CMOS camera, xyz translation stages, rotational vacuum pump, and a MS Windows XP personal computer running the data acquisition and evaluation software. A customdesigned, detachable measuring head of the instrument hosts the X-ray tube and a small vacuum chamber attachment. All the spectrometer components, except the vacuum pump, can be mounted on a custom-made transportable carriage frame.

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Fig. 1 Overall view of the portable X-ray fluorescence spectrometer. The spectrometer has been set up to directly characterize pigments on a test painting.

The X-ray fluorescence spectra of samples are excited using direct X-ray tube spectrum or a spectrum filtered through 50 micrometers thick Rh foil. The filtered mode is useful when analyzing polycrystalline type of materials to diminish the presence of interfering diffraction peaks and/or to improve the detection limits for certain elements. The X-ray tube is usually operated at 50 kV and 1 mA (50 W). The tube is powered by a manually controlled high voltage power supply. The accelerating voltage and current can be precisely adjusted within the ranges between 20.00 kV – 50.00 kV and 0.010 – 1.000 mA, respectively. The heat generated during the tube operation is dissipated through the tube housing, which is cooled down by a stream of air induced by build-in ventilator. When operated indoors, at room temperatures around 22 ºC, the tube temperature measured by an internal sensor never exceeds 30 ºC. The X-ray beam is collimated with a cylindrical, brass collimator (inner channel diameter equal to about 0.5 mm) or a polycapillary lens. For the polycapillary lens the effective beam spot diameter on the sample was measured by so-called knife-edge scan. The results of the measurements are shown in Fig. 2. The estimated full width at half maximum (FWHM) of the beam spot was equal to about 160 micrometers. The collimator and lens are mounted in a

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motorized holder allowing for fast switching between them without the need for any re-adjustment of the collimating/focusing device.

Fig. 2. Knife-edge scan over a beam spot obtained with polycapillary lens.

The detector is a silicon drift type (SDD). Its energy resolution is 140 eV at 5.9 keV and 3 microseconds shaping time. The detector active area is 10 mm2 and effective thickness is 450 micrometers. The principle of the SDD operation allows the detector to maintain very good energy resolution and stable peak position also at high counting rates up to 105 counts per second (cps). The SDD is very useful during in situ operation due to its thermo-electrical cooling (lack of a bulky liquid nitrogen dewar limiting the time of in situ operation) and also due to its high throughput. Very often the analyzed sample contains highly abundant matrix element, e.g. Fe or Ca, resulting in a signal which would saturate or significantly degrade performance of a standard Si(Li) detector preventing the analysis of major/minor and trace elements using the same measuring conditions. In case of routine sample analysis in laboratory environment the material may be processed to eliminate the highly abundant, interfering matrix elements prior the analysis. However, it is not the case during in situ operation or during a noninvasive analysis. Contrary to a typical Si(Li) detector the SDD can operate at high counting rates without noticeable X-ray spectra degradation, the peaks of major/minor and trace components of a sample are registered accurately during the same measurement. It simplifies the instrument operation and reduces the measurement time (all data are collected in a single measurement lasting a few minutes). Additional advantage of using common measuring conditions for all elements of interest is less complicated data evaluation. The amplified signal of the SDD (shaper output) is digitized in a portable analog to digital converter/multichannel analyzer (ADC/MCA) unit. The collected spectra are transferred for inspection, storage and further evaluation to a personal computer running MS Windows XP operating system.

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Fig. 3. Arrangements of the components in the vacuum chamber attachment.

The laser pointers and the miniature CMOS camera are used for precise selection of the irradiated area. With the aid of the xyz translation stages the instrument is aimed at a region of interest. The distance between the instrument and the sample is adjusted precisely so that the position of the X-ray spot on the analyzed object coincides with the point defined by two crossing laser beams. Only if the irradiated surface is at a proper distance the camera image shows one bright spot formed at the analyzed surface by the two crossing laser beams, otherwise, if the object is too close or too far, two spots are visible in the camera image. The pre-alignment of the laser pointers and the X-ray beam is done with a phosphor screen. Once the pre-alignment is completed it is valid until the collimator/polycapillary lens of the instrument is replaced. The alignment remains valid after switching between collimator and the polycapillary lens by using the motorized collimator/lens holder. The lasers can be switched off and in the camera image one can monitor the immediate vicinity of the analyzed region, otherwise difficult to observe due to relatively short distance (about 1-2 mm) between the instrument measuring head and the examined object. The whole procedure of positioning/selection of the region of interest can be accomplished without moving the sample. It is very useful during investigations of large objects, e.g. sculptures, wall paintings or other objects which can not be easily moved. For the analysis of small samples, e.g. coins, pieces of jewellery, small ceramic fragments, etc., the object can be mounted on a small xy translation table. The table is attached to the instrument measuring head. It allows for precise positioning of small objects without moving the instrument. The spectrometer is equipped with a compact vacuum chamber. The chamber is directly coupled to the X-ray tube. The chamber hosts the X-ray optics, detector, laser pointers, and a miniature CMOS camera. There is also an illumination photodiode installed to provide light for monitoring the vicinity of the analyzed region. A close up view of the chamber, with the front and top wall dismantled, and the arrangement of the instruments inside is shown in Fig. 3. Fully assembled chamber is equipped with a 7.5 micrometer thick Kapton window installed in the front wall. The window is transparent to X-rays and

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visible light. The air pressure in the chamber is maintained below 1 mbar by a rotation vacuum pump. The length of the path between the sample and the detector, as well as the path between the tube and the sample, still remaining at the atmospheric pressure is reduced to less than 2 mm. It reduces significantly the absorption of low energy X-rays in the X-ray tube-sample-detector path. The reduction of air path is necessary for efficient excitation and detection of the socalled low-Z elements, such as Na, Mg, Al, Si, P, S, and Cl.

Fig. 4. Detection limits of elements based on the measurements of the IAEA Soil-7 RM.

The detection limits of elements have been estimated by measurement of a well characterized sample in a form of pellet made of the IAEA Soil-7 Reference Material. The sample was measured for 1500 s live time at 50 kV/1 mA. The polycapillary lens was used to focus the unfiltered primary beam emitted by the Pd-anode X-ray tube. The obtained detection limits of elements are shown in Fig. 4.

3. APPLICATIONS The portable XRF spectrometer has been used to characterize chemical composition of several objects in the collections of the Kunsthistorisches (KHM) Museum (Museum of Fine Arts), Vienna. 3.1. Qualitative Analysis In Fig. 5 the spectrometer is shown during inspection of pigments in an Egyptian wooden stele, XXVI, Thebes 640B.C. The Egyptian blue pigment was identified by the presence of the peaks of Si, Ca, and Cu in the collected X-ray fluorescence spectrum.

47

a)

b)

Fig. 5. Direct in situ identification of Egyptian blue pigment (CaO·CuO·4SiO) in a wooden stele from XXVI, Thebes 640 B.C (Egyptian and Near Eastern Collection, Kunsthistorisches Museum, Vienna).

In Fig. 6 a richly decorated oriental saddle is shown. The presence of cinnabar, azurite, white, and lead has been confirmed. A qualitative analysis of the inorganic components is quite straightforward. It requires a proper energy calibration of the MCA which is usually achieved with measurement of two samples made of pure substances, e.g. titanium and molybdenum foils. Based on the positions of Ti-K! and Mo-K! peaks a liner relation is established between the channel number (x-abscissa) and the X-ray photon energy of the MCA spectrum display. When the energy calibration is done the positions of all the peaks present in the collected spectra can be expressed in kiloelectronovolts (keV), the characteristics peaks can be identified and associated with chemical elements present in the sample. Based on the peak proportions an experienced analyst may also estimate the concentration ratios of the identified elements. With additional information on the object, it is usually enough to confirm/exclude the presence of inorganic pigments, the use of specific technological process, reveal otherwise “invisible” patches of foreign inorganic substances younger than the original object, etc. In many cases the qualitative analysis will give enough information to answer the curator or restorer question. However, there are cases where precise knowledge about the chemical composition of the objects, its different parts, layers, or specific regions is of prime importance to determine the source of the material, to estimate the object age (indirectly), or to develop an optimum conservation strategy and to decide about the storage/exposition conditions. The determination of chemical composition of the sample (quantitative analysis) is

48

performed with the use of additional software. A few different approaches can be used, depending on the sample type, its degree of homogeneity, availability of standards and reference materials.

Fig. 6. Identification of pigments in an oriental saddle (Arms and Armour Collection, Kunsthistorisches Museum, Vienna).

3.2. Quantitative Analysis In a standard laboratory set up the chemical composition analysis is performed using well homogenized, specially prepared samples, e.g. pressed pellets or fused glass beads. In such a case the measurement geometry is well defined. For a well defined sample and measuring geometry the relation between the intensity of an X-ray peak and the chemical composition of the sample can be described analytically: E ' dI 0 $ )f (E, E , E ) ,( , c, c )dE (1) I = cG* (E ) K (E , E ) f (E , E , ) , ( , c, c K+

K+

!

max

Eabs

" % & dE #

K+

Abs

K+

j =1...n

Enh

K+

j =1...m

j =1...m

Eqn. (1) describes the intensity of an X-ray characteristic peak, IK!, excited in a multielemental sample with the use of polychromatic primary radiation as a function of the element mass fraction, c, and a number of other parameters including mass fractions of all other elements present in the sample, cj=1…n, geometrical constant (G), detection efficiency ("), intensity distribution of the primary radiation (dI0/dE), energy of the primary radiation (E), energy of the Xray peak (EK!), X-ray peak production cross-section (K), and the absorption and enhancement correction coefficients (fAbs and fEnh, respectively). The integral in Eqn. (1) goes over primary photon energies above the photoelectric absorption edge (Eabs) with the initial vacancy leading to the production of the characteristic peak up to maximum energy of photons (Emax) present in the primary excitation spectrum. The primary spectrum includes bremsstrahlung and characteristic radiation emitted by the X-ray tube, eventually modified by a filter or polycapillary optics. For samples similar in matrix composition and characterized by a limited variability of the analyte a simple linear relation between the analyte mass

49

fraction and X-ray peak intensity can be assumed. In such a case, for a given element and its characteristic peak, the absorption and enhancement correction coefficients can be regarded constant and sample independent. Also the integral becomes sample independent. All the sample independent constants can be merged together, including G and "(EK!), in one calibration coefficient, SK! : I K! = cS K! (2) Coefficient SK! is specific for a given characteristic peak and it is common for all samples characterized by similar matrix composition. For each analyte the coefficient SK! is determined by measuring a few calibration samples made of similar or the same material as the “unknowns” and characterized by other analytical techniques. Due to similarity of the calibration samples and the unknowns the interfering effects cancel out or are corrected by the calibration coefficient. It is also seldom that for each type of analyzed objects and analyte we find calibration samples very similar in matrix composition and characterized by other techniques to apply Eqn. (2). We would also like to determine the content of not just one or two elements but as many as possible. In such a case one can start with calibrating the spectrometer by using on Eqn. (1). A set of calibration standards prepared from pure substances, e.g. metal foils, oxides or other pure and stable chemical compounds is measured in well defined conditions (sample distance, incidence and exit angles, etc.). For each peak of interest a combined value of G"(EK!) is calculated, denoted as S’K!: (3) S K( + = c!

Emax

Eabs

I K+ ' dI 0 $ " K (E , E K+ )f Abs (E , E K+ , * , ) , c, c j =1...n )f Enh (E , E K+ , E j =1...m* , ) , c, c j =1...m )dE % & dE #

For other elements/peaks of interest not present in the calibration standards the corresponding values of S’K! can be obtained by interpolation. The concentration of elements in the unknown samples is done by solving a system of equations (at least one equation per each element to be determined): c= S K( + !

Emax

Eabs

...

I K+ ' dI 0 $ " K (E , EK+ ) f Abs (E , EK+ , * , ) , c, c j =1...n )f Enh (E , EK+ , E j=1...m* , ) , c, c j=1...m )dE % & dE #

(4)

The accuracy of calculations is better if the sum of the concentrations of elements is close to 100% or if the chemical composition of the sample matrix not detectable by X-ray fluorescence spectrometry is know and is included in Eqn. (4). The accuracy can be further improved taking into account the in-situ measuring conditions. It can be done by measurement of an additional reference

50

material (RM) sample with similar characteristics to the unknown in terms of composition, surface topology, grain size distribution, etc. The measurement can be used to correlate the known concentrations of elements in the RM, c’, with the ones obtained by solving Eqns. (4): (5) c! = kc The correlation coefficient, k, is then used to correct the concentrations

Fig. 7. Correlation between the determined and certified concentrations of elements in bronze standard samples.

determined in the “unknowns” of the type similar to the RM. Such approach allows for using one calibration for various materials with the aid of a few RM samples. Such approach was used for analysis bronze sculptures. In Fig. 7 a correlation is shown for bronze reference material samples. The method was applied for the determination of a bronze disk sculpture “Madonna and Child” by Donatello (Florence, 1444). The sculpture is shown in Fig. 8.

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Fig. 8. The portable XRF spectrometer positioned in the front of the Madonna and Child bronze disk sculpture by Donatello (Florence, 1444). The spectrometer has been set up to analyze the spot on the knee of the Child. The analyzed area, the red spot, has been marked with two laser pointers.

An X-ray spectrum of spot located on the forehead of the Child is shown in Fig. 9. Despite a lack of gold plating in this point one can notice the presence of gold. Relatively large peaks of Ca and Cl originate from patina.

Fig. 9. X-ray spectrum of a spot on the forehead of Child, from the bronze tondo “Madonna and Child” by Donatello.

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Several spots on the bronze sculpture were analyzed. By applying the model described by Eqns. (4) and taking into account the presence of Au and Hg in the gold plating layer the average composition of the bronze and the plating layer were obtained. The results are present in Table 1.

Bronze

Fe 0.1 - 0.2

Cu 65 - 75

As 0.03 - 0.2

Concentration, [wt. %] Sn Sb 15 - 27 4.1 - 9.2

Pb 0.5 - 1.3

Au -

Hg -

Gold 84-86 14-16 plating Table 1. Determined chemical composition of the bronze and gold plating of a bronze tondo Madonna a Child by Donatello (Florence, 1444).

Relatively high concentration of mercury in the gold plating layer confirm that the gold film was applied by using fire-gilding technique. The accuracy of the results obtained during in situ measurements is always less as compared to the results which could be obtained in a laboratory environment after sample preparation. It is in the range of 5% - 20% relatively. Also characterized with the portable X-ray fluorescence spectrometer was a precious goldsmith work, so-called Salliera by Benvenuto Cellini (1500-1571), see Fig. 10. The composition of the gold alloy was determined. As can be seen from the spectra presented in Fig. 11 the gold alloy is relatively pure with only minor presence of copper and silver. One can also notice the importance of selecting the proper measuring conditions for analysis of certain samples. In this case the use of Rh filter in the primary radiation path eliminates the presence of diffraction peaks in the XRF spectra and makes easier the interpretation of XRF data.

Fig. 10. Goldsmith work, so called Saliera, by Benvenuto Cellini (1500-1571). Determination of gold alloy composition.

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Fig. 11. X-ray spectra of the Saliera gold alloy. Top: direct excitation with not filtered X-ray tube readiation; bottom: direct excitation with 50 µm thick Rh filter in the primary radiation path.

4. CONCLUSIONS A portable X-ray fluorescence spectrometer has been designed and manufactured in the IAEA Seibersdorf Laboratories in collaboration with Atominstitute, Vienna, Austria. The spectrometer has been applied to chemical composition determination of pigments, alloys, and identification of inorganic components in the objects from the collections of Museum of Fine Arts, Vienna, Austria. The portable XRF technique allows for non-invasive identification and determination of inorganic components of analyzed objects. Other X-ray emission techniques, e.g. proton induced X-ray emission (PIXE) and electron probe micro-analysis (EPMA) are also applied for characterization of objects of cultural heritage in a nondestructive way. In recent years the International Atomic Energy Agency supported several regional and national technical cooperation projects and coordinated research programmes related to the utilization of nuclear related analytical techniques for the analysis and preservation of cultural heritage. The management and proper care of the cultural heritage is of importance for both the developed and developing Member States of the IAEA. Especially developing countries should take special care about their cultural heritage, which very often generates significant income due to the tourism and associated commercial activities. There is a need to share the knowledge about the advanced analytical techniques among the

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archaeologists, conservators, and museum curators. On the other hand the scientists and analytical specialist should get acquainted with problems and methods of the conservation science. The technical cooperation programmes and the general programme activities of the IAEA provide a platform for such collaboration on a regional and worldwide scale. LITERATURE 1.

C.R. Appoloni, M.S. Blonski, P.S. Parreira, L.A.C. Souza, Nucl. Instrum. Meth. in Phys. Res., Section A 580: 710-713 (2007).

2.

R. Cesareo, A. Castellano, G. Buccolieri, S. Quarta, M. Marabelli, P. Santopadre, M. Leole, A. Brunetti, Nucl. Instrum. Meth. in Phys. Res., Section B 213: 703-706 (2004).

3.

K. Castro, N. Proietti, E. Princi, S. Pessanha, M.L. Carvalho, S. Vicini, D. Capitani, J.M. Madariaga, Anal. Chim. Acta 623: 187-194 (2008).

4.

G. Buzanich, P. Wobrauschek, C. Streli, A. Markowicz, D. Wegrzynek, E. Chinea-Cano, S. Bamford, Spectrochim. Acta Part B 62: 1252-1256 (2007).

5.

K. Uhlir , M. Griesser, G. Buzanich, P. Wobrauschek, C. Streli, D. Wegrzynek, A. Markowicz, E. Chinea-Cano, X-Ray Spectrometry 37: 450 – 457 (2008).

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INTEGRATED GEOPHYSICAL TECHNIQUES FOR THE HIGHRESOLUTION STUDY OF ARCHAEOLOGICAL SITES * MICHELE PIPAN Department of Geological, Environmental and Marine Sciences (DISGAM), University of Trieste, via Weiss, 1 Trieste, 34127, Italy EMANUELE FORTE DISGAM - Exploration Geophysics Group, Near Surface Laboratory, via Weiss 1 Trieste, 34127, Italy We propose a combination of magnetic, electromagnetic (multi-fold ground-penetrating radar) and seismic (tomographic) methods and apply them to the study of three archaeological test sites. The buried archaeological remains in the areas of study are basically characterized by poorly known and variable size, geometry, location and physical properties. The integration of different geophysical techniques helps identifying, imaging and mapping anomalies of potential archaeological interest due to the sensitivity to different properties of the materials. The geophysical results are validated by archaeological excavations that uncover targets in the depth range between 1 to 5 meters from topographic surface.

1. Introduction Geophysical prospecting can provide archaeologists with crucial information about location, depth and characteristics of buried targets of potential archaeological interest. Such information helps archaeological teams in planning and optimizing excavations. Interaction between archaeological and geophysical teams is becoming common practice and successful results are reported by several authors (see e.g. [1], [2], [3], [7], [9], [10], [11], [15]). Nonetheless, the elusive nature of buried cultural heritage and the requisites for detailed site imaging and characterization, imposed by scientific research and engineering applications in areas of archaeological interest, drive geophysical research towards the implementation of advanced methods that can reduce uncertainties *

This work is supported by Halliburton-Landmark Academic Award to EGG-DISGAM, by PRINCOFIN 2006047924_003, by an Italian Ministry of Foreign Affairs’ grant in the framework of bilateral Algerian–Italian cooperation protocol.

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in high-resolution subsurface archaeo-geophysical studies. This study focuses on the integration of magnetic, electromagnetic (multi-fold ground-penetrating radar) and seismic techniques and on the test of the integrated techniques in selected archaeological sites where low contrast of physical properties and variable depth, size and shape of the targets create conditions of peculiar complexity for geophysical data analysis and interpretation. The primary objective is to perform a joint subsurface characterization based on the integrated interpretation of geophysical images and multiple geophysical information for each point in the volume of study. The task is accomplished through the application of 2-D multi-fold ground-penetrating radar (mgpr) methods, which provide 2-D and 3-D images as well as radar wave velocity fields and instantaneous radar trace attributes. Radar data are further integrated by magnetic measurements and, at one test-site location, by seismic tomography ([7]). The main benefits in the use of ground-penetrating radar (gpr) techniques are the unequalled imaging performances in the shallow subsurface, i.e. in the depth range of interest in archaeological studies (i.e. less than 20 meters at most sites; [5]). Multi-fold data acquisition and processing (see e.g. [2], [3], [4], [5], [6], [10], [12]) provide additional information and benefits, such as radar velocity field, radar wave attenuation as a function of offset, material characterization through radar trace attributes ([8], [14]), accurate localization of targets and image enhancement. Quantitative information, such as electromagnetic wave velocity and attenuation, can be linked to physical properties of the materials (dielectric constant, conductivity). Enhanced quality of the subsurface image, accurate target localization and shape reconstruction in 3-D and physical properties are crucial to reduce the intrinsic uncertainty in archaeo-geophysical data interpretation due to the unknown and highly variable characteristics of the buried targets. Recent improvements in data acquisition equipment and processing techniques resulted in outstanding outcomes of the application of magnetic methods to archaeological prospecting (see e.g. [1], (13]). The high sensitivity of modern magnetometers coupled with focusing of the analysis on small variations of the magnetic field (frequently less than 1 nT) allowed the identification of archaeological targets even in conditions where the contrast between magnetic susceptibility of archaeological targets and surrounding materials is very low. One important element in the successful application of magnetic techniques to archaeological studies is the geometrical patterns associated with buried foundations or remains of buildings, which make the interpretation of results unequivocal. Eventually, seismic methods are basically associated with insufficient vertical/horizontal resolution for archaeological applications. Nonetheless, ultra-high-resolution reflection methods, multi-component techniques and seismic tomography are opening the route towards an extensive use of seismics in archaeological prospecting, particularly where imaging

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capability is required beyond the depth range attainable by gpr methods (i.e. roughly depths greater than 20 m). We selected three test-sites to test mgpr methods integrated by magnetic and seismic techniques: one in Egypt (Medinet Madi, Fayoum), two in Italy (Aquileia, Udine). All of them are characterized by challenging subsurface conditions, mainly related to low soil-target contrast of physical properties. The results of the geophysical survey give evidence of subsurface anomalies of potential archaeological interest that were successfully validated by archaeological excavation.

2. Methods Multi-fold ground-penetrating radar, magnetic prospecting and seismic tomography are synthetically described to elucidate data acquisition and processing techniques applied in the study of the selected test sites. The interested reader will find more detailed descriptions of the methods in the cited scientific literature. 2.1. Multi-fold ground-penetrating radar (mgpr) Ground-penetrating radar (gpr) is a pulsed electromagnetic technique designed to detect dielectric discontinuities buried beneath the earth’s surface (see e.g. [16]). The basic system is composed of a couple of transmit and receive antennas, which are used to propagate wide-band electromagnetic radiation (in the range between 25 MHz and 2 GHz for most applications) and to detect the backscattering from targets. Arrival time and amplitude of the backscattered radiation are exploited to image dielectric discontinuities. Ursin [17] proposed a unified treatment of elastic and electromagnetic (EM) wave propagation in horizontally layered media and such formal equivalence allowed sharing procedures for analysis and data processing that are used in exploration seismology. Multi-fold gpr (mgpr) refers to the extension of the gpr method to multiple offsets, i.e. multiple transmit-receive couples separated by different distances [6], [10]. Such extension allows the application of techniques employed in multi-channel reflection seismics, with specific reference to image enhancement, focusing of backscattered radiation, target localization and evaluation of material properties from amplitude and arrival time of the backscattered radiation [18]. We used an ultra-wide band (UWB) system (RAMAC, Malå Geoscience) equipped with bow-tie shielded (250, 500 MHz) to test the mgpr method at the selected sites. A distance triggering device based on an electro-mechanical odometer was used to ensure constant 5 cm trace spacing. Average positioning

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accuracy was below 0.2% . Conventional single-fold methods [i.e. single and constant distance (offset) between transmit-receive antennas] were used in reconnaissance surveys at all test sites. We successively applied multiple common offset profiles, to obtain multi-fold sections with average 1200 % fold (i.e. 12 offsets for each data acquisition point). Data processing was based on the following sequence: velocity analysis, spherical divergence correction, predictive deconvolution, stack and post-stack time migration, band-pass filter, wavelet Transform (WT) based identification of weak reflectors in noisy background (deep contacts). The azimuth-offset analysis was performed on test profiles with different azimuth before mgpr data acquisition to select grid orientation and offset range.

2.2. Magnetic prospecting Magnetometry measures the Earth’s magnetic field and maps its variations in order to identify the location of subsurface sources of anomalies. The rapidly time-variant component of the geomagnetic field, mainly due to electric currents in the ionized layers of the upper atmosphere, imposes the use of at least two measuring devices to remove the time-dependent component. A practical solution is to measure the gradient of the geomagnetic field by keeping the two sensors at fixed and constant distance in space. We used a high-resolution cesium magnetometer with a sensitivity of ±0.01 Nanotesla (nT) to measure the total field and the vertical gradient between two sensors spaced 1 meter apart. Ten measurements per second were taken at walking speed and the use of markers, spaced 5 meters apart, allowed the correct georeferencing of each measured value. Time variation was removed from total field measurements by subtracting the average value calculated every 25 meters. Comparison of gradient and total field data confirmed the validity of total field correction. Total field data were thus mapped in a average range of ±5.0 nT from the mean calculated geomagnetic value. The values exceeding such range were basically associated with metal (iron) scraps or burned materials. A scale based on colour changes corresponding to 0.020 nT magnetic field variations was utilized to map total field measurements.

2.3. Seismic tomography Tomographic inversion aims at reconstructing the kinematical and/or dynamical characteristics of a medium through a detailed mapping of velocity and/or attenuation. We focused on the kinematical analysis and exploited direct arrivals of seismic waves, i.e. transmission through the volume of interest and

59

measurement of traveltimes from a set of source-receiver pairs to calculate the velocity field within a cone-shaped burial mound. The seismic source was a 2.5 kg hammer striking a cylindrical steel plate (12 cm in diameter, 3 cm thick). Data acquisition was performed at ground level to identify velocity anomalies related to the deeper sectors of the mound, where the funeral chamber was most likely located. We achieved a complete 2! angular coverage with dense angular sampling, namely 15° spacing among the 40 Hz geophones and the same angular value among the sources, the two arrays being staggered in space through a 7.5° shift. Traveltimes were picked from the first breaks of 398 raypaths selected out of a total of 576. 178 raypaths were discarded because they were associated with minimum offset source-receiver pairs that sampled only the shallow portion of the mound and provided no useful information for traveltime inversion. The computational grid for traveltime inversion was based on 400 square cells (1.2 m size). The selected cell dimension could be considered adequate to perform the localization of the funeral chamber, which was the primary objective of the study. We applied SIRT (Simultaneous Iterative Reconstruction Technique; [19], [20] , [21]) to reconstruct the velocity field. After picking of the arrival times, we traced curved rays through an estimated velocity model, segmented the raypaths into the pixels of the model, computed the time residual for each ray, and iterative back projected the time estimates to produce model updates ([19]). The inversion process was iterated 7 times, by performing cycles of forward traveltime computation, residuals determination, velocity field upgrading, until we obtained a RMS residual of 1.02% . This value corresponds to a global RMS residual of 0.38 ms, which is comparable with the precision in picking of first breaks. 3. Test site description 3.1. Test site A – Medinet Madi The site is located some 100 km to the south of Cairo (Egypt, Fig.1a), in the desertic area at the southern border of the Fayoum area. It is characterized by variable subsurface conditions, from regular layers of sandy loams produced by eolic deposition to localized build-ups of debris produced by demolished or fallen buildings, limestone blocks of variable size, adobe remains and vegetable fibres (palm leaves) used for shelters (Fig.1b). The mixture of sandy loam and adobe debris with high clay and organic matter content results in locally high conductivity (around 0.015 S/m from laboratory measurement). Conductive and chaotic materials are responsible for attenuation and scattering that locally reduce the penetration of radar waves and the amplitude of primary reflections.

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Figure 1. (a) Location map of test site A, Medinet Madi (Fayoum, Egypt); (b) Example of shallow stratigraphic conditions from archaeological excavation at the Medinet Madi site.

3.2. Test site B – Aquileia Aquileia was one of the largest towns of the Roman Empire and it is now one of the most important archaeological sites in northern Italy (Fig.2). The area, abandoned for centuries after destruction by barbarian invaders, was covered by a layer of fine-grained sediments (silty loams) of average thickness not less than 100 cm. The site selected for the test is a polygon of approximately 1500 m2 that borders the local cemetery to the south. Two sample cores obtained in a radius of 500 meters from the site show that the layer of archaeological interest is an allochtonous soil made of sediments ranging from sandy gravels to sandy pelites.

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Figure 2. Location map of test site B (yellow dot, Aquileia, Italy).

3.3. Test site C – Udine The site is a preserved late Bronze Age burial mound located in the alluvial plain of the municipality of Udine (Italy, [22]) and made of lenses of sediments n ranging from pebbles to clay. It has a conical shape with a maximum elevatio of about 4.5m above the surrounding ground level (Fig.3). The average diameter is 26.5m and the base area is about 550 square meters. We performed a complete topographic survey and obtained a Digital Terrain Model (DTM) of the mound, with precision in the range of ± 1 cm.

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Figure 3. Location map, image and Digital Elevation Model of test site C.

4. Results Multi-fold ground-penetrating radar and magnetic gradiometry give evidence of subsurface features of archaeological interest at test site A. The magnetic anomaly map (Fig.4a), obtained from data filtered in the range between ± 10 nT from mean geomagnetic field of the site, shows orthogonal alignments that are compatible with buried building remains and consistent with azimuth of the buildings exposed by archaeological excavation of neighbouring sectors. Vertical and horizontal slices of the mgpr data volume (Fig.4b,c) confirm the results of the magnetic survey and indicate that the top of the buried remains is located at an approximate maximum depth of 2.0 m from topographic surface, based on the velocity field obtained from mgpr measurements.

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Figure 4. Test site A: (a) magnetic anomaly map; (b) vertical cross-section of the mgpr reflection data volume (250 MHz); (c) horizontal cross-section of the mgpr reflection data volume (250 MHz, 25 ns two-way-time ! 1m depth)

A magnetic gradiometry reconnaissance survey was first carried out at test site B in order to focus the mgpr data acquisition on the magnetic anomalies of potential interest. The results show a peculiar pattern in the southern part of the explored sector, with a straight NNW-SSE path terminated by an NE-SW trending arch (Fig.5). Mgpr data obtained in this sector give evidence of sharp discontinuities located between 0.6 and 1.4 m from topographic surface (Fig.6a,b). Reflection coefficient analysis indicates that the deeper material is characterized by smaller dielectric constant. Such characteristic is compatible with a sediment-buried foundations/remains contact, where the latter can be made of limestone or brick and exhibit therefore smaller porosity and fluid content compared with the shallow unconsolidated sediments, as demonstrated by several similar cases in the Aquileia area. Eventually, horizontal slices of the mgpr data volume (Fig.6c) show reflection pattern that match the magnetic anomaly and support the hypothesis of a buried structure. The areal shape of

64

magnetic/mgpr anomalies is consistent with the perimeter of a circus, a hypothesis that is confirmed by the available documentary evidences.

Figure 5. Test site B: magnetic anomaly map.

Figure 6. Test site B: example of cross-section of the mgpr reflection data volume (500 MHz), (a),(b) vertical sections; (c) Horizontal section (25 ns two-way-time ! 1m depth).

The peculiar characteristics of test site C (burial mound) encouraged an integrated application of mgpr and seismic tomography to overcome the respective limits of penetration and resolution. Fig.7 is an integrated display of the seismic tomogram and two selected mgpr sections. The tomogram is obtained at present ground level and allows the identification of a remarkable

65

velocity anomaly (D) in the central-northeastern sector of the tumulus. The mgpr sections cross the mound approximately in NS and EW direction and intersect at the top of the tumulus. Clear radar reflector are interpreted in a vertical range (measured from the top of the mound) from 40 cm to nearly 500 cm. The archaeological excavation verified the deep anomaly identified by seismic tomography (D), which is associated with the funeral chamber. The shallow radar reflector are associated with layers and lenses of sediments laid down during construction and characterized by variability of grain size and composition.

Figure 7. Integrated display of mgpr reflection data (250 MHz) and seismic transmission tomogram at ground level.

5. Conclusions The integration of different geophysical techniques can reduce uncertainties in the interpretation of data from archaeological sites and improve both the quality of subsurface models and the amount of quantitative information extracted from the datasets. The geometric coherence of anomaly patterns in magnetic data is often a valid indicator of the presence of buried cultural heritage but even in the best defined cases it can provide only approximate information about burial depth and 3-D subsurface structure. Moreover, a quantitative characterization of

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the subsurface materials requires additional measurements to achieve a reliable inversion of physical (i.e. electromagnetic, elastic) properties of the materials. The proposed integration of magnetic methods with mgpr and seismic techniques provides an effective solution in terms of imaging capabilities and material characterization. Mgpr can image the subsurface with the highest resolution presently allowed by geophysical methods and it is therefore an ideal complement of magnetic methods in archaeological prospecting. Multi-offset radar data further allow estimates of dielectric constants and evaluation of conductivity of materials. The unequalled performance of mgpr is on the other hand limited where conductive materials (e.g. clay, salt or brackish water) are at the surface or in the top shallow layers. In such conditions, the penetration of radar waves is severely reduced and, in some cases, the application of mgpr is impossible. Seismic methods can overcome the limitations of gpr in terms of penetration, even though a resolution level compatible with archaeological applications requires the use of dedicated wide-band sources and measurement of the slower components of the wavefield (i.e. S-waves). Nonetheless, favourable topographic conditions allow the application of transmission tomography, which allows identification of anomalies (velocity, attenuation) related to elastic properties of the materials. The successful application of the integrated geophysical techniques to different subsurface conditions and buried targets shows the flexibility of the proposed method and the important contribution that geophysics can offer to the non-invasive study of archaeological sites. Acknowledgments This research was supported by a Halliburton-Landmark academic award, by PRIN-COFIN 2006047924_003, by an Italian Ministry of Foreign Affairs’ grant in the framework of bilateral Algerian–Italian cooperation protocol. We are grateful to Elena Barinova, Edda Bresciani, Paola Cassola Guida and Susi Corazza who coordinated the archaeological work at the test sites and helped in data interpretation.

References 1. 2.

Becker, H., and Fassbinder, J.W.E., 2001, Magnetic Prospecting in Archaeological Sites, Monuments and Sites VI, ICOMOS, Lipp GmbH Muenchen, ISBN 3-87490-675-2 Berard, B.A., and Maillol, J.M., 2007, Multi-offset ground penetrating radar data for improved imaging in areas of lateral complexity -

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5. 6. 7. 8. 9.

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11. 12.

13.

14. 15.

application at a Native American site, Journal of Applied Geophysics, 62, 167-177 Berard, B.A., and Maillol, J.M., 2008, Common- and multi-offset ground-penetrating radar study of a Roman villa, Tourega, Portugal, Archaeological Prospection, 15, 1, 32-46, DOI 10.1002/arp.319 Booth, A.D., Linford, N.T., Roger A. Clark, R.A., and Murray, T., 2008, Three-dimensional, multi-offset ground-penetrating radar imaging of archaeological targets, Archaeological Prospection, 15, 2, 93-112, DOI 10.1002/arp.327 Davis, J., and Annan, P., 1989, Ground-penetrating radar for highresolution mapping of soil and rock stratigraphy, Geophysical Prospecting, 37, 531-551 Fisher, E., McMechan, G.A., and Annan, P., 1992, Acquisition and processing of wide-aperture ground-penetrating radar data, Geophysics, 57, 495-504 Forte, E., Pipan, M., 2008, Integrated seismic tomography and Ground Penetrating Radar (GPR) for the high-resolution study of burial mounds (tumuli), Journal of Archaeological Science, 35, 9, 2614-2623 Lemke S. R., 2000, GPR attribute analysis, proceedings of SAGEEP 2000, 263-272 Neubauer ,W., Eder-Hinterleitner, A., Seren, S., and Melichar, P., 2002, Georadar in the Roman civil town of Carnuntum, Austria: an approach for archaeological interpretation of GPR data, Archaeological Prospection, 9, 135-156 Pipan, M., Baradello, L., Forte, E., Prizzon, A., and Finetti, I., 1999, 2D and 3-D processing and interpretation of multi-fold ground penetrating radar data: a case history from an archaeological site, Journal of Applied Geophysics, 41, 271-292 Pipan, M., Baradello, L., Forte, E., and Finetti, I., 2001, Ground penetrating radar study of iron age tombs in southeastern Kazakhstan, Archaeological Prospection, 8, 141-155 Pipan, M., Forte, E., Dal Moro, G., Sugan, M., and Finetti, I., 2003, Multifold ground-penetrating radar and resistivity to study the stratigraphy of shallow unconsolidated sediments, The Leading Edge, 22, 876-881 Schultze, V., Linzen, S., Schüler, T., Chwala, A., Stolz, R., Schulz, M., Meyer, H.G., 2008, Rapid and sensitive magnetometer surveys of large areas using SQUIDs - the measurement system and its application to the Niederzimmern Neolithic double-ring ditch exploration, Archaeological Prospection, 15, 2, 113-131, DOI 10.1002/arp.328 Senechal P., Perroud H. and Senechal G., 2000, Interpretation of reflection attributes in a 3-D GPR survey at Vallee d’Ossau, western Pyrenees, France, Geophysics, vol. 65, 1435 –1445 Witten, A.J., 2006, Handbook of geophysics and archaeology, Equinox Publishing Ltd, ISBN-10: 1904768601

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16. Daniels, D.J., (Ed.), 2004, Ground Penetrating Radar 2nd edition, The Institution of Electrical Engineers, ISBN 0 86341 360 9 17. Ursin, B., 1983, Review of elastic and electromagnetic wave propagation in horizontally layered, Geophysics, 48, 8, 1063-1081 18. Yilmaz, Ö., 2001, Seismic Data Analysis, Society of Exploration Geophysicists, Tulsa OK, USA, ISBN 1560800941 19. Brzostowski, M.A., and McMechan, G.A., 1992, 3-D tomographic imaging of near-surface seismic velocity and attenuation, Geophysics, 57, 3, 396-403 20. Menke, W., 1984, The resolving power of cross-borehole tomography, Geophys. Res. Lett., 11, 105-108 21. Tien-when, L., and Inderwiesen, P., 1994, Fundamentals of Seismic Tomography, Society of Exploration Geophysicists, ISBN 1 56080 028 3 22. Cassola Guida, P., and Corazza, G., 2002, Udine, S. Osvaldo tumulo protostorico. Scavi 2002, Aquileia Nostra, LXXIII, 754-757 (in Italian)

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THERMOLUMINESCENCE DATING AND CULTURAL HERITAGE MARCO MARTINI, EMANUELA SIBILIA Dipartimento di Scienza dei Materiali e INFN Università degli Studi di Milano-Bicocca Via Cozzi, 53 - 20125 Milano m,[email protected]

Thermoluminescence Thermoluminescence (TL) is the emission of light observed during the heating of insulating or semiconductor materials, provided that they have been previously exposed to ionising radiation (McKeever 1985; Martini e Meinardi, 1997; Chen and McKeever, 1997) This irradiation may take place in the laboratory or in a radioactive environment. Another possibility, which is exploited in dating applications, is when a naturally occurring material is irradiated by the radiation field of its natural surrounding. The exposure to radiation somewhat perturbs the initial stable configuration of the material and heating allows the release of the accumulated energy. The existence of thermoluminescence is linked to the internal ordered structure of insulators, and to the presence of defects in its lattice. The process can be described, in a simplified way, using the energy band representation of insulators and assuming the presence of two kinds of imperfection in the crystal, as shown in Fig.1. As a consequence of the exposure to ionising radiation, electrons and holes (a hole is a vacancy of an electron) are produced in pairs: they can be captured in specific defects called “traps”, whose energies are within the forbidden gap of the crystal. These traps are metastable, and usually the lifetime of the trapped charges, electrons and holes, is very long at room temperature. The higher the exposure to ionising radiation, the higher the number of trapped electrons and holes. When the temperature of the crystal is increased, the carriers are raised energetically and freed from their traps to the conduction band from which they can recombine one another, thus emitting TL.

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The curve representing the intensity of emitted light as a function of temperature is called glow-curve (Fig.2), and its shape and intensity depend on the material and on the characteristics of the irradiation field, i.e. the type and energy of radiation and its total amount. The study of the TL properties in a crystal is actually the study of the defects of its lattice and the understanding of the role played by defects and impurities in some physical properties of solids. TL is a very sensitive tool to detect imperfections even in very small quantities This last TL feature mentioned, i.e. its dependence on the amount of energy absorbed during irradiation, called “dose”, is important in the dosimetric applications of TL. (the SI unit for the energy absorbed due to the interaction of ionising radiation with matter, the dose, is the Gray (Gy ), corresponding to 1 Joule/kg). In many cases, in fact, the intensity of the TL is directly proportional to the absorbed radiation dose. Once the dose response is tested using calibrated laboratory irradiations, any unknown dose producing a given TL signal can be easily determined. Several artificial and naturally occurring materials show this favourable property, covering a very wide range of dose (10-2-108 Gy approximately). They are diffusely used in dosimetry and radiation protection practices and can be used to measure the doses due to professional exposure and those accrued as a consequence of nuclear accidents, as well as to monitor the dose inside nuclear plants. New materials have been developed to best fit the characteristics required by the main specific applications which are personnel, environmental, medical, retrospective and high-dose dosimetry (McKeever et al., 1995). Detection of TL signal The definition of TL itself suggests a rather easy way to detect it: what is needed is in fact an apparatus which is able to heat the samples under controlled conditions, and an efficient light detection system. In most cases, the very low level of the emitted signal and the difficulties in controlling and measuring precisely the sample temperature require the use of complex and specifically designed systems. This is particularly true when TL intensity is very low, like in dating applications or when basic studies on defect centres are carried out. In fig. 4 a schematic diagram of a TL measuring instrument is represented. Three main parts can be envisioned: the heating system, the detection system and the signal processing. The most common heating system is composed of a resistive planchet that heats up as a result of the passage of current through it. A common method of measuring the temperature is through the use of a thermocouple welded to the underside of the planchet. A photomultiplier tube (PMT) is normally used to detect the emitted TL. In fact the efficiency of high-

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gain, very sensitive PMTs allows the detection of very low level signals with a convenient signal-to-noise ratio. The recent development of high sensitivity light detectors, like intensified diode arrays and Charge Coupled Devices (CCD), has allowed the measurement not only of the amount of emitted light, but also of its wavelength (Martini et al.,1996), obtaining information about the centres involved in the recombination processes. An example of such spectra is reported in Fig. 3. Thermoluminescence dating Thermoluminescence dating is the only physical technique for determining the age of pottery presently available. It is an absolute dating method, and does not depend on comparison with similar objects. The application of thermoluminescence in archaeological and geological dating (Aitken 1985, 1990) is based on dosimetry: it stands on the fact that many naturally occurring TL mineral constituents of ceramics, including quartz and most feldspars, are able to act as dosimeters for the amount of ionizing radiation they are exposed to. This radiation mainly comes from the radioactive decay of uranium, thorium and potassium present in the ceramics itself and in its surrounding (typically the burial soil), at concentrations of a few part per million. The radioactive materials having long half lives of 109 years or more, the radiation flux is practically constant. An important point to single out is that, when pottery is fired, it loses all its previously acquired TL. Thus, after cooling, the natural radioactivity causes thermoluminescence to build up again so the older an object is the more light is produced (Fig. 5). The TL level measured in pottery is associated to the dose accumulated since it was fired in kiln , unless there was a subsequent reheating. Any heating at high temperature acts as a clock resetting event. This usually occurs when the items are heated over 400°C. In archaeology, thermoluminescence dating is specific for ceramics bricks, cooking hearths, incidentally or deliberately fired rocks such as flints or cherts. If the radioactivity of the pottery itself, and its surroundings, is measured, the dose rate, or annual increment of absorbed dose, may be computed. The age of the pottery, in principle, may then be determined by the relation Age = Absorbed dose / Annual Dose-rate Typically we are dealing with absorbed doses ranging from a few to a few tens of Gy. The dose-rate is usually within the range 1-10 mGy/year. Even if the principles on which TL Dating is based are rather simple, the practical procedures are not. The precise evaluation of both absorbed dose and dose-rate requires the consideration of various factors affecting the calculations. For example, one of this factors is the way in which the different types of

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radiation, α, β, or γ, are absorbed by the thermoluminescent minerals contained as small crystals in the pottery. The main dating techniques were developed on the basis of the differences in absorbing radiation by grains of different sizes. The so called "inclusion" technique (Fleming, 1970) considers only quartz crystal grains in the range 100200 µm extracted from the ceramic. The second major TL technique is the "fine grain" (Zimmermann, 1971) which uses all the material that can be extracted, for instance by drilling the sample. A grain size separation is then operated by settling the obtained powder in acetone suspension. It is possible to select a grain size range, typically between 1 and 8 µm. It must be mentioned that some complicating factors can occur, due to the specificity of the materials. In fact, while in dosimetry one can choose the best dosimeter available for a given radiation, in TL dating only the naturally occurring minerals can be used. The clay minerals have e usually low TL; a few of them are hardly thermoluminescent at all; some may not have a straight-line relationship between dose and TL. In addition, some of the accumulated signal may be lost due to thermal and anomalous fading (Wintle, 1973), where part of the TL is lost without thermal excitation, or it may exhibit a spurious, non radiation induced component (Martini et al., 1988). Also, if the sample was poorly fired in antiquity, the TL clock would not have correctly set to zero. The presence of one or more of these effects has great influence on the precision of the final result. If they are absent or small, or can be compensated or corrected for, then the error limits on the dates obtained are typically in the range ±4 to ±8% of the age. Dating applications TL might in principle be used to date any archaeological material containing thermoluminescent mineral and subjected in the past to an heating sufficient to erase any previous signal. Ceramics, due to its widespread diffusion in archaeological excavations, is the more frequent material submitted, toghether with bricks from historical buildings. The clay cores from lost wax metal castings may also be tested. Heated stone material, such as hearths, pot boilers, and burnt flints, can be dated as well, even if some regions are known to present problems for TL, like Indonesia and West Mexico: objects from these areas usually do not successfully yield TL dates, due to the very poor TL characteristics of the raw materials locally used. Possible applications of TL dating beyond man-made artefacts are geological field, where aeolian, fluvial, coastal and, in some cases, marine sediments can be dated. In these case the signal resetting is due to the exposure

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of sunlight during deposition. Also volcanic formations be dated. A few examples of application of TL Dating techniques in various archaeological fields are reported in detail in the next section. Excavation archaeology An interesting example in excavation archaeology is the case of Bet Gemal (Strus, 2003), an Israeli village inhabited from II century BC to the Islamic period (IX century AD). The site displayed exceptionally well preserved remains: a Roman-Jewish quarter, a Christian Byzantine settlement with several plants for oil and wine production (fig. 6) and an Islamic dwelling place. Each group of remains is relative to different chronological periods. The long occupancy of the site and the cultural and religious changes that took place resulted in a complex, cumbersome stratigraphy posing problems of absolute chronology, in particular regarding the duration of the different occupations. TL dating was performed on several domestic ceramics characteristic of the three periods. Supported by our results, listed in table III, the following absolute chronology of the site could be proposed. The Jewish occupancy had its break at the end of the I century AD, in the historic context of the Jewish-Roman Wars. For the two following centuries, the site should have been almost abandoned until the III century, when the repopulation of the site started and its prosperity grew; the remains of workshops of ceramics, wine and oil presses testify the economical prosperity of this phase. A successive development of the village occurred in the Byzantine period, linked to new constructions like a church and a further oil press that was functioning during the VI century. The last transformation of the village occurred during the VII century, after a destruction on a large scale probably due to the invasion of the Persian army in 614 AD or to the local Muslim victory over Byzantines in 643 AD. The destruction was followed by a general restoration of life, marked by the re-building of several houses and by new industrial and housing projects, until the final abandonment of the village somewhere in the IX century. The impressive stone structure depicted in fig. 6, the bigger of the three oil presses associated to the Byzantine phase, well testifies the economical importance of the site at that time. Another relevant application is the study of the chronology of the Cham civilisation, that developed in central and southern Vietnam from 6th to 16th century. In the frame of an Italian-Vietnamise Programme of Cooperation an extensive TL dating project of the MySon religious complex started in 2005. The site shows the remains of more than 70 buildings of different styles (Fig. 7) built in different periods but always with the same building technique. About

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300 bricks and ceramics have been sampled and the presently available results show evidence of a chronology much more complex than supposed by former scholars, especially for what concerns the important edification phases occurred during X and XI centuries. Historical buildings Since the stratigraphic techniques initially developed for archaeology, have been extended to architecture, the relative internal sequence of the various building phases of a monument can be usually precisely determined. Their absolute chronology is however sometimes problematic or controversial. In such cases, the contribution of the TL dating techniques could be conclusive (Galli et al., 2002). It must be reminded, however, that care has to be taken when associating the TL age of a brick to that of the structure it belongs to, because the event that is determined is the last firing of the sample. Voluntary human actions (rebuilding, transformation, decay and restoration) can modify the position of a brick in the stratigraphic sequence of a building. Moreover, in case of reuse of materials from pre-existing structures, dates are older than the building; in case of upkeep or mimetic restoration, dates are younger than the building. In case of fire, this event will be dated. The contribution of the archaeometric techniques to the study of ancient buildings is anyway very important. The main advantages of this kind of application are the availability of large quantities of material, the homogeneity of environmental radioactivity and the lesser extent of humidity fluctuation. TL dating in architecture should therefore give precision higher than in excavation archaeology, as confirmed by the statistical analysis preformed on about 1300 ceramic samples submitted to our Laboratory for dating over the last ten years (Martini et al., 2001). It could be appreciated that errors lower than 6% are much more frequent when dating buildings rather than excavated samples. As an example, we report the results recently obtained for the San Lorenzo Church in Milano The cathedral of S. Lorenzo in Milano (fig.8), the more ancient testimony of roman and palaeochristian architecture in Milan, is a complex architectural structure that shows evident traces of several building interventions often lacking of sure chronological attribution.. After performing a detailed stratigraphic analysis on both external and internal surfaces to fix the general building sequences, the different phases were dated with thermoluminescence and radiocarbon. TL was applied only to unbroken bricks and fictile tubes sampled in several wall structures of the complex.. Radiocarbon was used on wooden charcoal

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scrapes contained in the joint of mortars of walls. In absence of scrapes, calcium carbonates clots found in the mortars themselves were employed. In total , more than two hundred samples were analysed. The very good agreement of all the results relative to the original phase allowed to indicate the narrow period 390-410 A.D. for the foundation of the tetraconc, much storiographically significant than the previous ones, estimated on historical ground. Later medieval reconstruction phases, one of them interesting the dome during X century, have also been uncovered. Burnt flints The possibility of dating burnt flints by TL appeared soon a great challenge to contribute in studying sites whose age is beyond the upper limit of radiocarbon dating (about 40.000 years), and when organic materials are not abundant or not well preserved. Flint is dense siliceous sedimentary rock whose basic component is SiO2, occurring as silica, cristobalite/trydimite and α-quartz. Due to its hardness and conchoidal fracturing properties, it was largely employed in prehistory to manufacture a large number of artefacts (Fig. 9). Some of them were accidentally or deliberately heated and the burning is obviously essential for the erasure of the geological accrued TL. Goksu and co-workers (Goksu et al., 1974) highlighted the possibility of dating burnt flint, presenting at the same time the limits and the specific problems related to such materials: generally low TL sensitivity and sensitivity changes, spurious and regenerated TL and very low concentrations of radioactive elements, circumstance that attaches great importance to a precise evaluation of the ambiental dose-rate. Despite the problems encountered in this application, flint dating is widely used and the results played, for instance, a primary role in the revision of the chronology of the presence of Neanderthal man and of modern human in the Middle-East. We recently studied a group of 20 burnt flints from the prehistoric site of Fumane, in North Italy, Verona province (Martini et al., 2001). It is a huge cave, used as a shelter by ancient men, characterized by paleosurfaces extremely rich in bones and lithic objects. The study of this site is considered very important for the passage from Middle to Upper Palaeolithic and from Mousterian to Aurignatian age in Northern Italy and Europe. Some stratigraphic sequences of the site have been dated with radiocarbon but very few data regarding the human presence are available. The chronology obtained by TL, spanning from 79 + 11 ka to 57 + 12 ka BP, added key information to the archaeological and palaeoenvironmental history of this Pleistocene period, up to now poorly dated.

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Archaeological glasses The chemical-physical behaviour of silica glasses suggested the use of TL techniques as a suitable method to date these materials. Actually, because of the amorphous nature of glass, numerous factors reduce its thermoluminescence sensitivity. The main problems encountered in glass dating are a generally low TL sensitivity (TL emission per unit of dose) and the emptying of TL traps due to sunlight exposure or to t he low stability of TL traps at room temperature. Both effects result in a loss of TL signal. Moreover, changes in TL sensitivity often occur after repeated heating and irradiation of the same sample. Due to these difficulties, at the present state of the art only a few percent of the samples analysed could be successfully dated.. We focused our attention to a particular class of glass, the vitreous tesserae composing mosaics (Fig. 10). Our study was performed on samples chosen as representative of six sets of differently coloured glass mosaic tesserae. They all belong to wall mosaic decorations and were found in archaeological excavations or taken from mosaics to be restored, all well dated on archaeological grounds. The thermoluminescent emission of these vitreous materials, lacking a long range periodic structure, is due to the impurities present or added to the glass network (Al, Mn, Cr…), the colour centres acting as electron traps and recombination centres. In fact, a good natural TL emission was observed in almost all tesserae, the blue ones being generally characterised by higher sensitivity. Samples were submitted to different protocols for TL measurements, previously described hiavari et al., 2001) and their TL properties were investigated in deep. This allowed selecting eight tesserae characterised by suitable TL behaviour (high sensitivity, trap stability, low optical bleaching and limited changes in sensitivity after heating), that were submitted to dating. They presented a TL sensitivity comparable with that of ceramics materials. For the external annual dose-rates the mean values typical of the different provenance areas have been assumed, with errors taking into account possible wide variations. Under these assumptions, ages with overall errors ranging form 15 to 18% have been obtained. It is however noticeable the general consistency of TL dates with the archaeological ones. It is also remarkable that we could date eight tesserae over the nineteen analysed: the percentage of suitable samples was about 40 % against the 5% reported for glasses up to now (Chiavari et al., 2001).

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Clay-cores The first application of TL techniques to clay-cores dates back to 1974, when D.W. Zimmermann (Zimmermann et al., 1974) succeeded in testing the authenticity of core materials from a Bronze Horse of the New York Metropolitan Museum of Art. Further attempts devoted to dating, soon enlightened a series of difficulties, complications and limiting factors. First of all, the application is in principle possible only for the objects cast by lost-wax technique, using the remains of thermoluminescent clay-cores heated contemporarily to the casting itself. The possibility of dating such materials depends on its mineralogical composition, and particularly on the abundance of “good” thermoluminescent minerals like quartz and feldspars. A high concentration of carbonates and/or organic material is generally a disadvantage, for the associated spurious, not dose-dependent TL emission. Another phenomenon that is observed with higher frequency than in ceramics is the anomalous fading, a process which empties deep traps at room temperature. The evaluation of the environmental contribution to the annual dose-rate can be problematic, both for the often unknown “archaeological history” of the object to date and for the need to evaluate the shielding effect of the bronze layer on the external irradiation. Due to the sum of these circumstances, the achievable precision in dating bronzes is generally lower than in ceramics, the mean error being generally about +10% of the age. As a further remark, it must pointed out that dating the clay core is not dating the bronze statue itself, except when the correlation between the ages of the two objects is sure, or highly probable. It must be reminded that any TL dating refers to the last heating at high temperature experienced by the item to date: in case of restoration or repair performed by heating, this last event will be dated instead of the original one (Martini and Sibilia, 2003). The possibility of dating clay-cores is furthermore precluded if the object has been intensively radiographed before sampling out the core material. In such a case, unfortunately frequently recurring, the high energy X-ray exposure results in an accrued radiation dose that produces an additional TL emission, superimposed to the archaeological one. The evaluated palaeodose is consequently meaningless. Nevertheless, things are not always so discouraging, and often very satisfactory results can be obtained, like in the case of the Cellini’s Perseo (fig. 11) Benvenuto Cellini (Florence, 1500-1571) wrote that a "great cry of admiration" arose from the throng gathered to watch the unavailing of his Perseo in the Loggia dei Lanzi on April 27th, 1554. After about five hundred years of open air exposure, the state of conservation of the statue was critical,

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due to the polluted, aggressive urban atmosphere, transforming its historical patina from insoluble to soluble salts. It was therefore fully restored and again its disassembling gave access to its interior, where important fragments of claycore were found. In this case, TL dating was mainly performed to check the reliability of the technique, being the dating itself beyond dispute. The dating result, 1540+35 AD, is in very good agreement with the historical records, confirming the potential of such application, the reliability of the laboratory protocols and the accuracy and precision of instrumental calibrations. Conclusions TL dating of ceramic materials is nowadays a consolidated and powerful technique which supports the archaeological and archaeometric researches. Precisions as good as +5% in the evaluation of the age of various kinds of archaeological findings are often reached, allowing the solution of archaeological or historical problems arising from samples chronologically relatively close. A systematic comparison of TL dating results with those obtained by other absolute dating techniques like radiocarbon and dendrochronology and the dating of samples already well independently dated on archaeological or historical ground is highly recommended, in order to check and improve precision and accuracy of the laboratory experimental procedures.

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References 1. Aitken, M.J. Thermoluminescecene Dating, Academic Press, New York, 1985 2. Aitken M. J., Science-based Dating in Archaeology, Longman, London, 1990 3. Chen R. and McKeever S.W.S, Theory of Thermoluminescence and Related Phenomena, World Scientific, Singapore, New Jersey, London, Hong Kong, 1997 4. Chiavari C., Martini., Sibilia E. and Vandini M., Quaternary Science Reviews 20 (2001) 967. 5. Fieni L, Galli A., Martini M., Montanari C.,Sibilia E., Proceedings of the 34th Int. Symposium of Archaeometry, Zaragoza, 2004. 6. Fleming S.J., Archaeometry 12 (1970) 133. 7. Galli A., Martini M., Montanari C. and Sibilia E., Proceedings of the 33rd International Symposium on Archaeometry, Amsterdam, 2002. 8. Goksu H.Y., Fremlin J.H., Irwin H.T., Fryxell R., Science, 183 (1974) 651 9. Martini M. and Meinardi F., La Rivista del Nuovo Cimento, 20 (1997) 1. 10. Martini M., Paravisi S.and Liguori C., Radiation Protection Dosimetry, 66, (1996) 47. 11. Martini M., Sibilia E. , Proceedings of the International Conference Archaeometallurgy in Europe, Milano, 2003. 12. Martini M., Sibilia E. and Ferraro L., Proceedings of the 3rd International Conference on Science and Technology for the Safeguard of Cultural Heritage in the Mediterranean Basin, Alcalà de Henares, 2001. 13. Martini M., Sibilia E., Calderon T. and Di Renzo F, Nuclear Tracks, 14 (1988) 339. 14. Martini M., Sibilia E., Croci S. and Cremaschi M., Journal of Cultural Heritage, 2 (2001) 179. 15. McKeever S. W. S., Thermoluminescence of solids, Cambridge University Press, Cambridge 1985. 16. McKeever S.W.S., Moscovitch M. and Townsend P.D., Termoluminescence Dosimetry Materials: properties and Uses, Nuclear Technology Publishing, Ashford, 1995 17. Strus A., Khirbet Fattir-Bet Gemal. Two Ancient Jewish and Christian Sites in Israel, (LAS, Roma) 2003 18. Wintle A.G., Nature 245 (1973) 143. 19. Zimmermann D.W., Archaeometry 13 (1971) 29. 20. Zimmermann D.W., Yuhas S.M.P. and Meyers P., Archaeometry 16 (1974) 19

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Figures

Fig.1. Traps levels in an insulating crystal

Fig.2. Examples of TL glow-curves

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Fig.3 Ancient mosaic glass.Wavelength resolved TL spectrum

Fig.4: Diagram of a typical TL measuring system

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Fig.5: TL growth vs time

Fig. 6 Bet Gemal excavation site

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Fig. 7: A ruined tower at the MySon religious complex

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Fig. 8: Back view of S Lorenzo Church in Milano

Fig. 9 Archaeological flints

Fig.10: Byzantine mosaic glass tesserae

Fig. 11: Benvenuto Cellini, Perseo

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NEW X-RAY DIGITAL RADIOGRAPHY AND COMPUTED TOMOGRAPHY FOR CULTURAL HERITAGE F. CASALI , M. BETTUZZI, R. BRANCACCIO, M.P. MORIGI Physics Department, University of Bologna and INFN, Bologna, Italy X-ray detection systems for high resolution Digital Radiography (DR) and Computed Tomography (CT) have been developed at the Physics Department of the University of Bologna. The target of the research is the development of systems to be applied in cultural heritage conservation and industrial radiology. In the field of cultural heritage, different kind of objects (ancient necklaces, paintings, bronze or wooden sculptures) have to be inspected in order to acquire significant information as the method used to assemble, the manufacturing techniques or the presence of defects. These features could be very useful, for example, for dating works of art or determining appropriate maintenance and restoration procedures. Among the advanced methods available, 3D CT can be successfully used for the investigation of ancient works of art because it preserves their integrity and provides images of inner parts, otherwise not visible. Several high-resolution CT systems, to investigate objects of different sizes (from micro to macro), have been developed at our Department and will be presented in the paper. Some experimental results will be presented too as the micro CT reconstruction of Roman human tooth with carious, the cone beam CT analysis on an Egyptian cat-shaped coffin exhibiting the inner mummy, the CT of an ancient large globe (2 m of diameter) located in Palazzo Vecchio, at Florence, as well as some large painted tables of great artistic interest (i.e. a painting of Raffaello). KEYWORDS: X-ray tomography, micro-tomography, X-ray diagnostics, inner inspection, imaging, 3D reconstruction Contact: [email protected]

1. INTRODUCTION The first, natural, application of tomography was the study of the human body. The impact of this technique in diagnostic medicine has been revolutionary, since it has enabled doctors to view internal organs with unprecedented precision and safety to the patient. Thus, several medical CT systems were developed and today this diagnostic technique is well consolidated. The application of tomography to the Cultural Heritage and industrial fields represents instead an interesting innovation.

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Medical CT is optimized for the human body (composed mainly by water) and cannot be successfully used on dissimilar objects like those of interest in the field of cultural heritage. In order to perform good, non-destructive evaluations, the most suitable CT system (source, moving equipment, detector and elaboration software) must be carefully chosen to avoid obtaining meaningless results. For that purpose, several X-ray CT systems have been developed at the Physics Department of the University of Bologna designed for specific applications. For small objects (i.e. fossil teeth and ancient jewels) it is necessary to use radiation source having very small focal spot and high spatial resolution detectors. For big or thick objects it is necessary to use highly penetrating radiation sources, very efficient detection systems and very advanced mathematical methods for the reconstruction of the 3D images. Commonly X-ray tubes up to 450 kV are used but a certain interest in high energy CT (i.e. LINAC with more than 1 MV) is now growing up. The detectors developed and used, at our laboratory, are of one dimensional type (linear detectors) as well as two dimensional type (planar detectors). Linear detectors work with a “fan beam geometry” and one-dimensional projections are collected, while planar detectors permit to obtain two-dimensional projections in “cone-beam geometry” [1], [2]. By processing the acquired data with dedicated algorithms, it is possible to reconstruct the two-dimensional inner slice in case of linear projections and the whole 3D volume in case of the two-dimensional ones. Moreover, by means of a dedicated translation axis, the 3D volume can be achieved with linear detectors in scanning mode. Descriptions are given below on the different kinds of equipment developed, considering Cultural Heritage and Industry requirements as well.

2. FAN BEAM SYSTEM Intensified Linear Detector. An interesting innovative detector has been developed at the Department of Physics of the University of Bologna. The main objective was to obtain a wide and intensified linear detector that maintains high spatial resolution. The absence of intensified linear CCD on the market brought us to adopt an innovative solution for the problem: to change the format of a standard intensified CCD camera using a suitably sized coherent fiber optics image guide. By using an intensified camera, we obtained an intensified linear detector [3]. The main components are an intensified digital camera and a coherent linear-to-rectangular fiber optics guide coupled with the photocathode of the camera (see Figure 1). The innovative element of the system is the FO guide, consisting of seven coherent fiber optics bundles arranged in such a way to

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transform an almost linear area (128.8 mm x 1.45 mm) into a rectangular one. The FO guide output is directly coupled with the EBCCD’s photocathode. A layer of gadolinium oxysulfide (GOS) converts the X-rays into visible light on the input side of the FO guide. In this way an intensified multi-slice linear detector (5600 ! 35 pixels) was obtained. The system is able to make digital radiographies using doses equal to about 1/100 of the standard ones. The detector can be arranged either in Digital Radiography mode (DR) or in Computed Tomography (CT) mode by means of a high-precision translation and rotary mechanical device [3]. Figure 2 shows the CT of an osteoporotic bone [4] an of a tree. The spatial resolution is very high (about 30 microns) for such big samples so it is possible to detect the bone trabecula and the tree rings.

Figure 1. Diagram of the experimental set-up of the linear scanning system.

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Figure 2. CT of an osteoporotic bone (a) and of a tree trunk (b).

3. CONE BEAM SYSTEMS

When using a cone-beam CT system information can be retrieved as 2D cross-section images or 3D full-volume images allowing the inspection and the classification of the object; moreover, by processing tomographic data, a 3D numerical model of the sample can be obtained for virtual reality applications or digital archives storage. 4. Micro-CT system

A micro-CT system has been set up on the basis of an X-ray detector developed within the framework of a collaboration with the Geosphaera Research Center of Moscow [5]. The detector consists of a Gd2O2S:Tb phosphor layer (30 mg/cm2) deposited on the entrance window of a 2:1 glass fibre-optic taper. The small face of fibre-optic taper is then coupled to a cooled Charged Coupled Device (CCD). The CCD has 1024!512 useful pixels and a 12 bit ADC. Pixel size is 15!15 µm2; therefore the effective area of the

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detector is about 30!15 mm2 with a detection pixel size of about 30!30 µm2 [6]. The high resolution obtained (20÷30 µm) allows a detailed analysis to be made of the inner structure of fragments of fossils, artefacts and rocks. For example, the micro-CT system has been used in the analysis of paleobiological samples. In collaboration with the Anthropology Section of the National Museum “L.Pigorini” in Rome, a detailed program of micro-CT analysis has been set up for the investigation of paleoprimates [7]. Figure 3a shows the picture of a human molar from the necropolis of Isola Sacra, near Rome [8]. Tomography (Figure 3b) allows a 3D reconstruction of the tooth with a resolution of 30 µm (voxel side). Successively, through virtual cuts, parts of the volume can be removed to provide an inside view of the sample, enabling tooth lesions to be easily located (Figure 3c). A specific diagnosis of caries can be made with certainty based on the results of this analysis.

Figure 3. Picture of a human tooth. (a) 3D reconstruction of the tooth. (b) Virtual cut into the volume in order to locate the lesion (c).

Thanks to the high image resolution and definition of this detector, small rock samples can also be investigated in order to extract geological information. With this detector a rock samples can be analysed in order to study the included minerals as can be seen in Figure 4a and 4b.

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Figure 4 . Rock sample with minerals enclosed. Tomographic reconstruction (a), segmented minerals (b).

5. Intensified tomographic system for medium-size objects.

Another tomographic system is based on an innovative EBCCD (Electron Bombarded CCD) camera (developed by Geosphaera Research Center), which has a very high sensitivity (about 5!10-5 lux) and allows the detection of low-light images, reducing exposure time and irradiated dose [9]. This EBCCD camera consists of a 24 mm photocathode, a high voltage intensifier tube (ranging from 5 to 10 kV) and a CCD chip with 1024!512 useful pixels of size 13.3!13.1 µm2 each. Electrons extracted from the photocathode hit directly the substrate of the CCD that is sealed inside the tube. In this way an higher conversion efficiency and an higher gain (up to 2000) are obtained with respect to conventional image intensifier. A 12-bit ADC, on the border of the EBCCD electronics, provides the digital output. A diagram of the intensified CT system is shown in Figure 5.

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Figure 5. Diagram of the intensified CT system.

A micro-focus X-ray source provides a cone-beam source, which irradiates the object, projecting its attenuation profile on a 30x40 cm 2 GOS screen, placed in the entrance window of a large light-tight box. The light image produced on the screen is focused on the EBCCD photocathode by means of a lens. A programmable turntable rotates the sample with a fixed angular step and a set of digital radiographs of the object is collected at different points of view. The radiographic data are then processed and cross-section images of the object are reconstructed by means of specific mathematical algorithms. The set-up is similar to that of micro-CT system, but this intensified system makes it possible the investigation of bigger objects (several tens of cm of size) with a resolution of about 200 m, that is certainly better than that provided by standard medical CT scanners. Thanks to a collaboration with the Archaeological Museum of Bologna, this tomographic system has been used to inspect important archaeological samples, such as bronze objects of the Etruscan section and small mummies from the Egyptian Collection [10]. Among the samples investigated, particularly interesting is a catshaped coffin (Figure 6a). The size of the sarcophagus is 37.7!10!19.5 cm3 and it has a structure composed of different materials. CT data allow very fine distinctions to be made among materials with different densities, thus providing a large amount of information. Figure 6b shows a 3D reconstruction of the sarcophagus, while figure 6c shows how it is possible to extract the cat’s skeleton for a detailed analysis of the mummy.

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Figure 6. (a) Photograph of a cat-shaped coffin (Archaelogical Museum of Bologna). (b) 3D reconstruction (voxel side ~600µm). (c) Extraction of the cat skeleton, shown in white, from the volume. whole

Transportable CT system for large objects. As valuable works of art can be hardly moved outside the museum in which they are located, there is a strong interest in the development of CT systems specifically designed for Cultural Heritage analysis on-site. In order to fulfill this requirement our research group developed the transportable CT system shown in Figure 7, which has been conceived also for the investigation of large objects.

Figure 7. Scheme of the transportable CT system: the X-ray tube is on the right, the investigated object at the center and the detector on the left.

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The design of this system is very different from any commercial available CT machine. It consists of a portable 200 kVp X-ray source, a detector and a motorized mechanical structure for moving the detector and the object, in order to collect the required number of radiographic projections necessary for the tomographic reconstruction. The CT detector consists of a 450!450 mm2 scintillator screen (1 mm thick structured cesium iodide), optically coupled to a 2184!1472 cooled CCD camera (Apogee Alta U32). Visible light photons produced by the scintillator are then collected by the CCD camera, equipped with a photographic lens. Thanks to a 45° mirror, the camera is not placed directly on the primary beam for not damaging it and for decreasing the noise, due to the direct interaction of X-rays with the CCD. The CCD camera, the mirror and the scintillator are positioned in a light-tight box, mounted on a horizontal translation axis. The object is fixed over a rotating plate that is placed at a certain distance along the source to detector axis. If the size of the sample is larger than the Field Of View (FOV) of the detector, it is possible to move the detector along the horizontal axis and to translate the object in the vertical direction by means of a lifter. Thanks to a collaboration with the “Opificio delle Pietre Dure”, the most important Italian restoration institute in Florence, it was possible to transport and mount the CT system inside the shielded laboratory of the “Opificio”, where CT scans were performed on several works of art under restoration in the institute. One particularly interesting case is the famous panel painting “The Goldfinch Madonna (Madonna del Cardellino)” by Raffaello [11]. In Figure 8 a digital radiograph and a 3D tomographic reconstruction are shown.

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Figure 8. (a) Digital X-ray radiograph that shows the presence of: 1) nails used to assemble the pieces of the painting; 2) wooden inserts; 3) breaks of the wood with lacks of the original painted layers. (b) 3D tomographic reconstruction showing the discontinuities in the painted surface.

Another interesting tomographic analysis regards the big globe ended in 1571 by the Dominican monk Egnazio Danti and located in Palazzo Vecchio, at Florence, Italy (Figure 9). Within the restoration project (sponsored by the Municipality of Florence), a CT of the globe was achieved, for exploring the nature and the conditions of the inner structure [1], [12]. The main problem of getting a complete CT was related to the large size of this masterpiece (220 cm in diameter) and to the need of achieving an in situ analysis in a museum with a

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lot of visitors. For these reasons an ad hoc experimental apparatus was realized and set-up at Palazzo Vecchio. The diagram of the CT system is shown in Figure 10. The 3D CT reconstruction of the globe has clearly shown the entire inner structure that was never seen before (Figure 11), how it was deformed during time, how it could be restored. All the inner structure, made of iron with a total weight of about 350 kg, was estimated from the segmented 3D reconstruction.

Figure 9. The globe in the Room of Maps (Sala delle carte) in Palazzo Vecchio (Florence)

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Figure 10. Drawing of the used CT system .

Figure 11. Tomographic reconstruction of the globe internal structure.

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6. Conclusions

Digital radiography and computed tomography are two new and interesting fields of non-destructive evaluations and a tool for scientific investigations. It should however be pointed out that the CT technique is difficult and expensive. In fact, for having good CT images, many hundred of radiographies are necessary with the use of very expensive equipment for moving the objects with a precision of a few microns. The easiness with which CT can be performed in the medical field may be misleading: medical CT was optimized for the human body (composed mainly of water) and cannot be successfully used on bodies with different density. In order to perform good, non-destructive evaluations, the most suitable digital radiography or computed tomography system (source, moving equipment, detector and elaboration software) must be carefully chosen to avoid obtaining meaningless results. Different digital systems have been developed at the Physics Department of Bologna University for tomographic analysis of Cultural Heritage samples or for industrial applications. The developed systems have been tested on various objects. With a field of view of approximately 3 centimeters, a resolution of 30 microns has been obtained with the microtomographic instrument in the study of archeological teeth or with rock samples; while a resolution of 200÷300 microns is achievable by means of the intensified tomographic system investigating objects of medium size and density such as in the case of the Egyptian mummy. As valuable works of art can be hardly moved outside the museum in which they are located, a transportable CT system for large objects has been realized. This instrument has been tested several times: at Opificio delle Pietre Dure (Florence), at Royal Palace of Venaria Reale, at Palazzo Vecchio (Florence) and National Museum of Asmara (Eritrea) where a fossil skull (one million year old) was analysed. Last but not least, we studied and developed an intensified multi-slice linear detector (5600 ! 35 pixels) that can be arranged either in digital radiography mode or in computed tomography mode by means of a high-precision translation and rotary mechanism. The system is able to make digital radiographies using a dose equal to about 1/100 of those usually used, achieving very high resolutions (about of 22 microns with a 20 centimeters field of view [13]). This instrument has been tested on an industrial component and on a trunk of a tree. Here, growth rings are clearly visible in the reconstruction. Our experimentations show the high success of computed tomography applied to Cultural Heritage. Our studies strongly encourage to proceed with the researches.

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7. REFERENCES [1] – “X-ray and Neutron Digital Radiography and Computed Tomography for Cultural Heritage”, Franco Casali, Physical Techniques in the Study of Art, Archaeology and Cultural Heritage, Chapter 2, Vol. 1 (2006) 41- 123. [2] – “High Resolution Computed Tomography for Industrial Applications based on Coherent Fiber Optics Ribbons”, M.Bettuzzi, R.Brancaccio, A.Berdondini, M.P.Morigi, F.Casali, A.Flisch, A.Miceli, Proceedings of 5th World Congress on Industrial Process Tomography, pp. 958-964, 3rd-6th September 2007, Bergen, Norway [3] – "A new system for Digital Radiography and Computed Tomography using an intensified linear array detector", F.Casali, A.Pasini, M.Bettuzzi, R.Brancaccio, S.Cornacchia, M.Giordano, M.P.Morigi, D.Romani, Proceedings of International Symposium on Computed Tomography and Image Processing for Industrial Radiology, Berlin, June 2003, pp 317–324, BB 84–CD. [4] – “High resolution X–ray analysis of a proximal human femur with synchrotron radiation and an innovative linear detector”, M.Bettuzzi, R.Brancaccio, F.Casali, S.Cornacchia, E.Di Nicola, N.Lanconelli, L.Mancini, M.P.Morigi, A.Pasini, D.Romani, A.Rossi, IEEE Nuclear Science Symposium and Medical Imaging Conference, Roma,16–22 Ottobre 2004, Nuclear Science Symposium Conference Record, 2004 IEEE Volume 5, 16–22 Oct. 2004 Page(s):3312 – 3315 [5] – “An experimental micro-CT system for X-ray NDT”, M.Rossi, F.Casali, M.Bettuzzi, M.P.Morigi, D.Romani, S.Golovkin, V.Govorun, Proceedings of SPIE's 46th Annual Meeting (San Diego, California USA, 29 July- 3 August), SPIE, USA, 2001. [6] – "Development of high resolution X–ray DR and CT systems for non medical applications", F.Casali, M.Bettuzzi, R.Brancaccio, S.Cornacchia, M.Giordano, M.P.Morigi, A.Pasini, D.Romani, F.Talarico, Proceedings of International Symposium on Computed Tomography and Image Processing for Industrial Radiology, Berlin, 23–25 June 2003, pp.329–336, BB 84–CD. [7] – “Analisi di reperti fossili mediante microtomografia computerizzata.”, M.Rossi, F.Casali, D.Romani, L.Bondioli, R.Macchiarelli, L.Rook, II Convegno Nazionale di Archeometria (Bologna, 29 January-1February) Patron Editore, Bologna, Italy, 2001, p. 91-98. [8] – “Advanced methods in human osteodental paleobiology; The 'Isola Sacra Project'”, L.Bondioli, R.Macchiarelli, in International Symposium Humans from the Past: Advancement in Research and Technology, Roma, Italy, 1997. [9] – “Digital radiography using an EBCCD-based imaging device”Rossi M., Casali F., Golovkin S.V., Govorun V.N., Applied Radiation and Isotopes 53 (2000) 699-709.

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[10] – “Computed Tomography of an egyptian cat-shaped coffin with mummy”, M.Rossi, F.Casali, D.Romani, D.Picchi, Proceedings of the “5th Internationa Topical Meeting on Industrial Radiation and Radioisotope Measurement Applications” (Bologna, 9-14 giugno 2002) J.E.Fernandez e A.Tartari, Editrice Compositori, Bologna, 2002 [11] – Capitolo “Indagine tomografica”,Franco Casali, Maria Pia Morigi, Matteo Bettuzzi,, Rosa Brancaccio, Irene Bernabei, Andrea Berdondini,Vincenzo D’Errico nel Volume "Raffaello: il colore rivelato ..." a cura di Marco Ciatti, Cecilia Frosinini, Antonio Natali, Patrizia Rintano attualmente in corso di stampa. [12] – “X–ray computed tomography of an ancient large globe”, F.Casali, M.Bettuzzi, D.Bianconi, R.Brancaccio, S.Cornacchia, C.Cucchi, E.Di Nicola, A.Fabbri, N.Lanconelli, M.P.Morigi, A.Pasini, D.Romani, A.Rossi, Optical Methods for Arts and Archaeology Conference, edited by Renzo Salimbeni, Luca Pezzati, 13–14 June 2005, Munich, Germany. Journal: Optical Measurement Systems for Industrial Inspection IV. Edited by Osten, Wolfgang; Gorecki, Christophe; Novak, Erik L. Proceedings of the SPIE, Volume 5857OV–1, pp. 253–260 (2005). [13] – “High resolution X–ray analysis of a proximal human femur with synchrotron radiation and an innovative linear detector”, M.Bettuzzi, R.Brancaccio, F.Casali, S.Cornacchia, E.Di Nicola, N.Lanconelli, L.Mancini, M.P.Morigi, A.Pasini, D.Romani, A.Rossi, IEEE Nuclear Science Symposium and Medical Imaging Conference, Roma,16–22 Ottobre 2004, Nuclear Science Symposium Conference Record, 2004 IEEE Volume 5, 16–22 Oct. 2004 Page(s):3312 – 3315

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COSMIC RAYS FOR ARCHAEOLOGY GIANROSSANO GIANNINI† Physics Department, University of Trieste, Via Valerio 2, Trieste, 34127, Italy Cosmic rays are the natural phenomenon due to elementary particles reaching from galactic space the Earth atmosphere. Cosmic primary particles, mainly protons, produce showers containing many secondary particles of which some, called muons, are able to propagate to ground and even penetrate underground. By using suitable detectors deployed underground a sort of density variations radiography, related to buried structures of archaeological interest, can be obtained. Measurements with instrumentation built on purpose by a collaboration between physicists of the Universities and the INFN Sections of Trieste and Perugia have been performed at the Arcaeological sites of the Aquileia Roman Port and at the Claudus and Trajan Emperors Ports near Fiumicino-Rome, Italy.

1. Cosmic Rays Radiography A group of physicists of the Universities and the INFN Sections of Trieste and Perugia have developed a procedure called Muon Ground Radiography (MGR) which exploits the natural phenomenon of Cosmic Rays to obtain radiographic type images of underground buried structures of archaeological interest. The detectors for measuring muon intensity and angular distribution underground have been designed, built and operated in several archaological sites of which the experiences at the Ancient Roman Ports remains in Aquileia and at the Claudius and Trajan port area in Fiumicino near Rome are here reported. 1.1. Cosmic Rays from Galactic Space to Earth The Earth atmosphere is continuously reached by energetic elementary particles, mostly protons but also other heavier nuclei are present, from the galactic space in which they are accelerated to reach almost the speed of light. Primary particles, with a flux of about 1000 per second per square meter, upon hitting atmospheric atoms nuclei, produce showers, with many secondary

†

Work partially supported by Italian Nuclear Physics National Institute INFN-Trieste, and Regione Friuli Venezia Giulia L.R. n.3/1998, art.16, 2002.

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particles of which the most penetrating ones are called muons (Figure 1) and are able to attain sea level and even continue underground or in thick materials.

Figure 1. Galactic Cosmic Rays produce in the atmosphere showers with penentrating muons

The muon flux, of about 100 per second per square meter, will be attenuated depending on the amount of mass traversed. Measuring muon flux versus direction allows to determine the amount of material traversed above. 1.2. The Cosmic Rays detector Cosmic ray muons detection was achieved by building a device with high energy physics advanced technology based on scintillating fibers and bars with multianode photomultipliers, readout by compact VLSI electronics (Fig.2,3).

Figure 2. Muon Ground Radiography MGR Detector based on scintillating fibers and bars.

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The detector is housed in a aluminum waterproof cylinder (Fig.3) to be lowered underground in an excavated hole.

Figure 3. Galactic Cosmic Rays produce in the atmosphere showers with penentrating muons

1.3. Underground Radiography The Muon Ground Radiography concept is represented in Figure 4. By measuring the cosmic ray muon flux for few days there is enough statistics to reconstruct different density features in soil like stone, marble or cavities of down to about 10-20 cm in size .

Figure 4. The detector from ~ 15 m underground can radiograph a conical shaped volume above it.

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2. Cosmic Rays Archaeological Applications The first use of cosmic ray muons to detect density fluctuations in structures for archaeological purposes dates back ~40 years and is due to Luis Alvarez [1] for the search of new hidden chambers in the Chefren Pharaon Pyramid. This pyramid is somehow peculiar for not having two burial chambers like the pyramid of his father Cheope, and the one of his grandfather Snefru, but only one known chamber. This led to the hypothesis of a hidden chamber; and to find it the directional flux of cosmic rays inside the pyramid was measured using a muon detector based on streamer chamber. Considering the shape of the pyramid and its material density the conclusion was for no evidence of hidden chambers. More recently the technique of measuring the directional flux of cosmic muon underground was used in the determination of the shape of the cavity in Grotta Gigante (near Trieste, Italy) [2]. 2.1. Underground Radiography in Aquileia The first site selected by our Trieste-Perugia group was near the Roman Port in Aquileia (Fig.5), the second largest town in Italy at the time of the Roman Empire, known to have large amounts of unexplored archeological ruins.

Figure 5. Applications of comsic ray radiography in Aquileia, Italy

The precise place where to install the detector underground was near an already excavated area on the unexplored side. The decision followed a large area Laserscan from helicopter, covering ~10 km2, from which clearly appeared topographic features related to underground archaeological structures (Fig. 6)

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Figure 6. Laserscan topographic color coded rendering of Aquileia with archeological features.

The Muon Ground Radiography selected site near the Roman Port area with the protection hut for the detector and equipment is shown in Fig. 7.

Figure 7. The roman Port Area and the MGR equipment protection hut.

The data taking performed in the summer 2003 allowed to “see”, buried road sidewalks, column bases and walls (Fig. 8) in agreement with other measurements using Georadar prospection techniques in the same area.

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Figure 8. Cosmic ray muon ground radiography of the Roman Port in Aquileia Underground Radiography in Fiumicino

The town of Fiumicino near Rome is where the Claudius harbour and Trajan port were the largest ones of the Roman Empire in the Mediterranean Sea (Fig.9).

Figure 9. Some historical images of the port structures now mostly buried under Fiumicino.

The old structures are today almost completely buried underground and the most advanced exploration techniques are tried to find archaeological remains. Our group has performed exploration activities in 2004 with Laserscan,

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Ortophoto (Fig. 10) on a wide area (~15 km2), together with Georadar and cosmic ray muon radiography data taking in selected zones.

Figure 10. Ortophoto of the Fiumicino area showing the Trajan lake once the Trajan Port.

In the selected place a ~15 m deep hole was excavated (Fig.11) for lowering the MGR detector (fig.12)

Figure 11 . The excavation of the hole for installing the MGR detector underground.

The position for installing the detector was chosen because it was still unexplored but, being higher by ~ 5 m with respect to the surroundings (its even known as “Mount” Giulio), is most probably hiding interesting archaeological remains corresponding to commercial activities near the port as goods storage, water tank replenishing reservoirs for ships or cisterns.

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Figure 12. The MGR detector being lowered in the hole underground.

The large amount of data collected is still being analyzed by the Archaeological Authorities and the cosmic ray muon radiography method

Figure 13. The Cosmic ray muon radiography plot superimposed to georadar measurements.

worked well and allowed to indicate the position of buried walls near a cistern, but much more is expected to be obtained. References 1. 2.

L. Alvarez et al., Science Vol. 167 (1970). E. Caffau et al., Nucl. Instr. and Meth. A 385, 480-488 (1997).

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SOME EXAMPLES OF EXAMINATION, CHARACTERISATION, ANALYSIS & CONSERVATION TECHNIQUES DEDICATED TO ARCHAEOLOGICAL ARTEFACTS JEAN LOUIS BOUTAINE Centre de Recherche et de Restauration des Musées de France (C2rmf) Paris – France The examination, characterisation and analysis of archaeological artefacts requires various complementary techniques, in order to improve our knowledge concerning their component materials, their elaboration processes, their evolution and/or degradation according time, use and environment and thus to give indications for their restoration and/or conservation. The present paper will give some guidelines relative to the importance and the usefulness of such techniques. This will be illustrated by some examples taken among recent works on artefacts from various geographical origins, various ages and different materials. Moreover, some examples of techniques of consolidation of archaeological artefacts will also be presented. A comprehensive bibliography is attached.

1. Why science & technology for cultural heritage? The problems to be solved can be of one or other of the seven following types: 1. Determination of the nature of the component materials of an artefact 2. Dating 3. Determination of the creative process of a material or of the artefact itself 4. Evaluation of the suffered alteration processes and estimation of their importance 5. Diagnosis of previous modifications or restorations 6. Assistance to the conservator/restorer 7. Forecasting and optimisation of the short and long term destiny in the present conservation conditions (i.e. preventive conservation) To resolve one or several of these issues the conservation scientist and the conservator need a palette of non destructive and non invasive techniques of examination, characterisation or analysis of archaeological artefacts and their conservation, in order to improve our knowledge concerning their component materials, their elaboration processes, their evolution and/or degradation

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according time, use and environment and thus to give indications for their restoration and/or conservation. 2. Some preliminary remarks Deriving from my professional experience, firstly, in an applied physics laboratory working for cultural heritage institutions, and secondly, as head of the Research Department of the Centre for Research & Restoration of the Museums of France (C2RMF), I want to insist on some points which are not often mentioned in the community of conservation science: 2a Necessity of crossing results from methods based on different physical or chemical processes. Due to the broad diversity of materials, and as the artefacts have often various, complex and undetermined compositions, as their elaboration processes are often unknown or at least uncertain, it is generally useful or necessary to combine various examination, characterisation and analysis methods, in order to get pertinent information (Ciliberto [1], Janssens [2], Creagh [3], van Grieken [4], Pollard [6]). 2b Cutting edge technologies must not conceal classical everyday work techniques: Two examples: Digital photography During a conference [8] in Malacca (Malaysia) in 2004, a very interesting paper was presented, relative to the potential of a commercially available digital camera, modified in order to make also infrared photography. This permitted to extend the range of the useful wavelength up to 1000 / 1100 nm. As the performances (sensors resolution and zoom lens range) are regularly improving in commercially available digital photographic cameras, such a protocol could be largely used. This is an excellent illustration of “low cost technology” adapted to cultural heritage examination (infrared photography is an important tool in this area). Alternatively, at the C2RMF (Paris), recently (since December 2003), a new development relative to a digital multi-spectral photography protocol occurred [9] The equipment and the protocol adopted permit one to realise sequentially, with the same operating conditions: classical photography, infrared photography, UV fluorescence photography and raking light photography. The equipment consists in a Hasselblad H1 type still digital camera, auto-focus with adapted lens (f = 80 mm), Imacon CCD detector 4000 x 5000 pixels, practical

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equivalent sensitivity up to 200 ISO, useful wavelength ! " 1050 nm (N.B.: for silver halide films, ! " 900 to 1000 nm), used with a video monitor. Such an equipment is used for laboratory or in situ examination, for instance: paintings of the Galerie d’Apollon, Musée du Louvre (Paris) before restoration. In this case the sketch was 12 m in length, and distance from object to camera: 25 m. For UV fluorescence one uses a classical flashlight without protective cache, with 3 to 5 flashes. For IR photography one uses a filter transparent to infrared, the sensor being modified on C2RMF request, with the infrared absorbing filter being dismounted, and set on demand, outside the camera. X-ray fluorescence analysis One must not forget commercially available portable XRF devices and focus on PIXE or synchrotron radiation techniques to realise elemental analysis of cultural heritage components. 2c Nobody is in a position of mastering the more suitable techniques for various sets of cultural heritage artefacts, so there is a necessity of working in networks. Here are some successful examples of European networks active in this area: Progetto Finalizzatto « Beni Culturali » - (CNR Italy) http://www.area.cs.cnr.it/cnr/pf/beni.html CHIMART (CNRS France) http://www.c2rmf.fr/pages/page_id18509_u1|2.htm Red Tematica de Patrimonio Historico y Cultural (CSIC – Spain) http://www.rtphc.csic.es/ COST G7 http://alpha1.infim.ro/cost COST G8 http://www.srs.dl.ac.uk/arch/cost-g8 ENVI-ART - COST D42 http://www.echn.net/enviart EU-ARTECH http://www.eu-artech.org 2d One must be vigilant of not concentrating all the efforts on famous artefacts and, as a consequence, ignore and/or leave to irremediable degradation less prestigious artefacts collections which could eventually be more significant milestones of the mankind history

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2e One should also always consider the potential use and/or transfer of technology of examination and analysis techniques developed in technical research centres dedicated to various industrial materials (glass, stone, wood, cast metals, ceramics…) 3. Examination, characterisation, analysis of cultural heritage artefacts Some demonstrative examples of study-restoration-conservation of famous cultural heritage artefacts can illustrate these remarks. All of them were subjects of successful multidiscipline projects: 1.

Satiro danzante di Mazzara del Vallo (Sicilia, Italy) [26] The bronze statue of the "Satiro danzante“ was fished out in the Canale di Sicilia in1998, on a bed of 500 m. It represents a mythological figure, a demon, part of the train of Dionysus, god of the wine. The artefact (2.50 m height) could be an original from the Hellenistic era (IV – III Century BC), or a more recent replica from the end of 1st Century AD. The statue is now kept in the Museo del Satiro, a Mazara del Vallo. (Scientific team; Giorgio Accardo – Istituto Superior per la Conzervazione ed il Restauro - Roma)

2.

Nebra sky disc, Halle (Germany) [27] The Himmelsscheibe von Nebra (sky disc) is a bronze disc of around 300 mm diameter, patinated blue-green and inlaid with gold symbols, excavated in 1999, near Nebra, Sachsen-Anhalt (Germany), dated to c. 1600 BC, associated with the Bronze Age Unetice culture. Copper came from Eastern Alps and gold from Carpathian basin. The disc and its accompanying finds are now in the Landesmuseum für Vorgeschichte of Sachsen-Anhalt - Halle (Germany). (Scientific team: E. Pernicka – TU Bergakademie Freiberg)

3.

Leopards weight of Shahi Tump (Balochistan), National Museum, Karachi (Pakistan) [28] & [29] The artefact was discovered in a grave, in the Kech Valley, in Balochistan, southern part of present Pakistan. It belongs to the Shahi Tump – Makran civilisation (end of 4th millennium – beginning of 3rd millennium BC). Height: 200 mm; weight: 13.5 kg. The shell (e = 3 mm) has been manufactured by lost-wax foundry of a copper alloy (12.6 % Pb, 2.6 % As), then it has been filled up through lead (99.5 %) foundry. The shell is engraved with figures of leopards hunting wild goats, made of polished fragments of shellfishes. No identification of the artefact’s use has been

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given (Fig. 1). (Scientific team: B. Mille, D. Bourgarit (C2RMF), R. Besenval (Musée Guimet –Paris) 4.

Venus Genitrix, or Aphrodite – Roman marble replica (1st Century AD) of a bronze Greek original (5th century BC) - Louvre Museum [30] & [31] The examination (gamma radiography and UV photography) before restoration has been conducted in order to understand previous restorations (Scientific team: B. Bourgeois (C2RMF – Versailles), B. Rattoni (CEA – Saclay) & D. Bagault (C2RMF – Paris))

5.

Canthare with storks – Boscoreale treasury, close to Pompei, Vesuvio eruption 79 AD, Musée du Louvre - Paris [32] The radiographic examination permits to establish conclusions relative to the manufacturing and the shaping of the artefact: different techniques were used in addition to each other, twofold shell, casting, then hammering, machining, stapling and brazing (Fig. 2). (Scientific team: D. Robcis & T. Borel (C2RMF) – Paris).

4. Some examples of conservation techniques ARC-Nucleart in Grenoble (France) is a co-enterprise CEA – Ministry of Culture – City of Grenoble – Rhône-Alpes Region. This Centre, achieving research and conservation / restoration, masters different techniques of consolidation of archaeological artefacts: sterilisation using gamma irradiation, NUCLEART process based on high energy gamma polymerisation, PEG (polyethylene-glycol) impregnation, lyophilisation. So, the Centre is in a position to choose the more appropriate technique for a given kind of artefact (nature of the materials, state of degradation, size…). The techniques are complementary and can be applied to artefacts made of materials like: dry wood, stone, water logged wood, leather, basketwork [125] to [130]. Some examples can illustrate the large scope of archaeological objects which can be treated by one of this palette of conservation techniques (Fig. 3, 4 & 5). 5. Conclusion After this very brief summary of the applications of science & technology to the study, the restoration and the conservation of cultural heritage artefacts, the reader can take benefit of the following wide list of references.

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their triacylglycerols: application to archaeological remains, Analytical chemistry, 79, 16, 6182-6192, (2007) 118. M. Regert, Elucidating pottery function using a multi-step analytical methodology combining infrared spectroscopy, chromatographic procedures and mass spectrometry, in: Theory and practice of archaeological residue analysis, [Ed] H. Barnard and J. W. Eerkens. British Archaeological Reports S1650, pp. 61-76 (2007) 119. M. Regert, Produits de la ruche, produits laitiers et matières végétales : quels vestiges pour appréhender les substances naturelles exploitées par l’homme pendant la préhistoire?, in J.P. Poulain [Ed] L'homme, le mangeur et l'animal. Qui nourrit l'autre ?, Les Cahiers de l'OCHA, Paris, 12, 50-64 (2007) 120. F.H. Schweingruber, Trees and wood in dendrochronology, Springer, Berlin (1993) 121. M. Kaennel, F.H. Schweingruber, Multilingual glossary of dendrochronology, Paul Haupt Bern, available at Swiss federal institute for forest, snow and landscape research, Birmensdorf (Switzerland) (1995) 122. J.H. Townsend, K. Eremin, A. Adriaens, Conservation science 2002, proceedings of a COST G8 meeting, Edinburgh (May 2002), Archetype Publishing, London (2003) 123. B. Brunetti, AM. Johansson, Science and technology for the conservation of the European cultural heritage – Research infrastructures, Report EUR 20483 (2003) 124. A. Denker, A. Adriaens, M. Dowsett, A. Giumla-Mair, COST action G8: non-destructive testing and analysis of museum objects, Fraunhofer IRB Verlag, Stuttgart (2006) 125. R. Ramière, Le laboratoire NUCLEART et le Centre d'étude et de traitement des bois gorgés d'eau à Grenoble, in Musées et collections publiques de France, Association générale des conservateurs des collections publiques de France, Paris (1987) 126. Q.K. Tran, R. Ramière, A. Ginier-Gillet, Impregnation with radiationcuring monomers and resins, in Archaeological wood: properties, chemistry, and preservation, 217-233, American Chemical Society, Washington (1990) 127. H. Bernard-Maugiron, A. Ginier-Gillet, X. Hiron, Le traitement des bois humides : bateaux et sarcophages, Les dossiers d’archéologie, 153, 24-31 (1990) 128. Q.K. Tran, X. Hiron, E. Damery, Traitement de la pirogue néolithique P6 de Paris-Bercy : de l’extraction à la conservation muséographique, Proc. 6th triennial meeting of the ICOM-CC working group on waterlogged wood, York (United Kingdom) 9-13 Sep 1996 129. P. Velay, Du chantier au Musée Carnavalet, Archeologia, 370, 18-19 (2000) 130. G. Chaumat, Q.K. Tran, P. Descalle, Densification de répliques en plâtre en vue d'une exposition à l'extérieur, in Le plâtre: l'art et la matière, Créaphis, Paris (2001)

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Fig 1 - The Leopards weight from Shahi Tump - Photography and 30 MeV accelerator tomodensimetry showing the copper shell and the lead filling

Fig 2 - Canthare with storks – Boscoreale treasury, close to Pompei, Vesuvio eruption 79 AD, Musée du Louvre - Paris – Photography and X-ray radiography showing details of the manufacturing process

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Fig 3 – Shoe - XIVth Century, leather, Brandes (Isère) lead-silver mine, Musée de l’Alpe d’Huez, consolidation process: lyophilisation – Photography before and after consolidation and restoration

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Fig 4 – Virgin - XIVth Century, wood, Flavigny sur Ozerain (Côte d’Or), consolidation process: Nucléart

Fig 5 - “Trébuchet” (balance) box - 575-660 AD, yew, boxwood & bronze, 190*70*40 mm, the bronze weights show the effigies of emperor Justinius II (565-578) & empress Sophia, excavated in 1994 from the shipwreck of La Palud I Port-Cros Island, Musée historique de Marseille, consolidation process: lyophilisation

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PRESENTATION OF DEMGOL: ONLINE ETYMOLOGICAL DICTIONARY OF GREEK MYTHOLOGY E. PELLIZER University of Trieste, Italy

What is known as Western Culture was built over the course of three millennia on the basis of two “Great Codes.” Encoded in the Germanic and Neo-Latin languages that spread over a significant part of the globe, these “Codes” engendered numerous literary and figurative works (as well as philosophies and even theologies) in the traditions of various nations. As shown by Northrop Frye, one of these “Codes” had its origin in the Jewish tradition, in the Torah itself and in the various elaborations of this text, as represented by the writings of the most important and widespread monotheistic religions (the Bible, the Koran, etc.). This “Code” influenced primarily Protestant, German- and English-speaking cultures. The other, however, indubitably goes back to the Greco-Roman tradition, which was preserved and transmitted from antiquity to modern times, endowing Europe with a huge patrimony of fictional tales, both religious and - to use a convenient label “mythical” texts. Today, modern information technology offers students, teachers and scholars unprecedented and unfettered access to this vast store of mythological, literary and historico-religious material in the form of multimedia and multilingual dictionaries and encyclopaedias. Combining ease of use and rapid access, these tools provide an advanced system for exploring the semiotic analysis of texts and other materials as well as for evaluating the impact of ancient myth on the figurative arts in contemporary culture. The Research Group on Myth and Mythography (GRIMM), based out of the University of Trieste’s Department of Sciences of Antiquity "Leonardo Ferrero," has furnished a considerable body of work intended for inclusion in a wide-ranging project known as the Online Etymological Dictionary of Greek Mythology (DEMGOL). Stemming from the doctoral dissertation of Carla Zufferli (University of Trieste), this work is being carried out by Ezio Pellizer (University of Trieste), with contributions from Francesca Marzari (Siena), Luisa Benincampi (Trieste), Alberto Cecon (Trieste) and other GRIMM

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members; Francesca Marzari and Françoise Létoublon (Grenoble) are working on the French translation (HOMERICA Group, Grenoble); Álvaro Ibáñez (Granada), José Antonio Clúa Serena (Barcelona) and Diana de Paco Serrano (Murcia) are working on the Spanish translation. Other versions are currently being planned, including versions in English and Portuguese. Publication of the Dictionary on the World Wide Web is being undertaken by Giovanni and Nevio Zorzetti on the University of Trieste’s “Hirema” (Historical Resources Management) Laboratory, deploying an application in the Java scripting language that allows contributors to edit and translate the text in a collaborative environment and to bring completed work immediately on-line. The project was conceived as an update of Carnoy’s Dictionnaire etymologique, which is now obsolete and which tends to seek out “Pelasgic” etymologies, often explaining obscura per obscuriora; it also improves upon Room’s Classical Dictionary, which is popular with the English-speaking public but limited in size, addressed to non-specialists, and deficient in both citing the main sources of myths and providing full and reliable etymologies (cf., e.g., the etymon of Antigone). Each entry in DEMGOL includes essential information on the character of the myth and mentions the ancient Greek and Latin sources of major relevance, without attempting to replace the many dictionaries of mythology now widely available. Furthermore, it is generally more detailed in the matter of minor and less well-known figures; in these cases, the main ancient sources are quoted with the aim of providing a historical perspective for the mythological accounts. This is followed by a meticulous study of the most plausible etymologies of the names of the heroes, heroines, gods, animals and monsters of Greek myth. The working methodology of the Dictionary is based on a careful analysis of the etymologies suggested by the scholars in the past, starting from Pape and Benseler’s list or the entries of Roscher’s Lexikon, now more than a century old, and continuing through the most recent research of Frisk, Chantraine, Wathelet, Zamboni, Salvatore, von Krafft and so on. The most plausible and linguistically substantial of these suggestions are chosen, and, wherever possible, Mycenaean attestations of anthroponyms or individual etymological components of those names are mentioned. At present, the work is undergoing continuous scholarly revision and careful editorial control, as the entries are uploaded to the database where they can be consulted immediately on the World Wide Web. In this way, the opportunities for expanding, revising and improving each entry are great, since it is easy to make additions, corrections and new entries or add new images remotely by computer. As of September 2008, there are about 890 entries in

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Italian, with over 700 translated into Spanish and 400 into French. For the yet un-translated French entries, an experimental system of “Controlled Automatic Translation” is being carried out by computer experts working with a team of scholars at Grenoble’s HOMERICA Centre. If this proves successful, this system will be extended to the on-going Spanish version, as well as the planned English and Portuguese versions. Currently, each entry contains dozens of images and links to other relevant websites; soon, however, hundreds of mythological images will be available on a global scale, mainly for modern and contemporary art and graphic art. Finally, testing is being carried out by an international committee of scholars and referees (A list is given on the first page of the GRIMM website, http://www.units. it/~grmito/ - GRUPPO). Because of the quantity of images and links that connect certain entries to other websites - pointing up the broad influence that Greek mythology has had on the culture of modern Europe and still has on contemporary society -, DEMGOL has great promise as a tool both of educational development and scholarly outreach, even at great distances. Even scholars who tend to favour material culture in the study of ancient civilizations will understand the importance of such a versatile analytical tool: it can be extremely useful in reconstructing the narrative or thematic structures of a huge deposit of cultural materials stratified through the development of Greco-Roman, medieval, Renaissance and modern culture, in terms both of the literary and folk forms of imaginative production, and of the iconic forms of European figurative art (above all in a Warburghian perspective that is open to the contribution of ethno-anthropological research). The structure of the work itself allows the reader to consult partial sections, such as the “Vocabulary of Symbolic, Hybrid and Monstrous Animals,” or a category of myths related to astronomy (“catasterisms”) recording the numerous heroes, heroines or animals transformed into constellations. To this end, the iconographic apparatus in DEMGOL should prove of great use (IMAGES section). Thanks to the structure and the capabilities of the electronic database, these images can be multiplied to such an extent that it will be possible to offer a very wide survey of the iconic forms that myth has assumed diachronically in figurative art in Europe, from the Middle Ages and the Renaissance to today. Unlike other paper or computer tools now in existence, DEMGOL pays particular attention to the presence of this cultural heritage in contemporary graphic art and art, on a global and worldwide scale. Needless to say, the entries available in DEMGOL today (which is already useful and operative, even if incomplete: over 1000 items have been planned)

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are linked to one another internally, allowing the reader to consult the Dictionary quickly and effectively, both for research and instruction, in three major languages spoken in Europe as well as in South America, Frenchspeaking Canada and the Philippines. DEMGOL has also been recommended by INTUTE (http://www.intute.ac.uk/), a website which gives information on “high-quality Internet resources for education and research.” For example: if one wished to expand and extend a study of the “mythical” models of some famous figures of ancient statuary - such as the famous Apoxyòmenos of Lo!inj -, DEMGOL provides an easy and quick way to research the typology of the young man of ephebic age, like Hyacinthus and Narcissus (fig. 1). Similarly, if one wished to see what the ancient Greeks meant by “Satyr,” DEMGOL makes it easy to go back to the images of the famous Satyr of Mazara del Vallo, with an meticulously researched etymology. The effectiveness of this tool is even greater in the study of mythical themes, however, which, while mostly Hellenic, entered into the astrological (and partly astronomical) traditions of the Western and Arab worlds. Of course, everyone knows that Jupiter, Saturn, Mars and Venus are late-Latin translations of planets that for centuries were called Ares and Aphrodite, Zeus and Cronos, and that nearly all the constellations have Greek names. By selecting DEMGOL’s category “catasterisms,” visitors can explore the numerous myths that can be “read” in the stars, viewing Canis Minor (Maira or Mera, fig. 2), Hydra or Cetus (Kétos) or sea monster (fig. 3): Villa Farnese, Caprarola. There is no need to linger long on the importance of this tool for the scholar who would like to deepen his or her knowledge of the vague, unclear and imprecise notion of “myth”—a concept that covers a series of cultural realities being studied by modern anthropologists, theologists and historians of religion, making use (at least beginning with Lévi-Strauss) of theoretical and methodological tools similar to those used by students of the “exact” sciences, such as linguistics and cultural semiotics. When studying the two (or three) millennia that have witnessed the development of the cultures of medieval and modern Europe in the Mediterranean, DEMGOL can be used as a kind of compass for navigating the (hopefully calm!) seas of culture and science in the contemporary world, as a consideration of the fundamental heritage of themes and structures, tales and images in the study of its origins, in religion, philosophy, literature, art and science, is absolutely indispensable. So far, GRIMM has received funding from the following sources: a grant from the Rhône-Alpes region of Grenoble (2006, EU 25.000=), along with funding from the Italian Ministry of Scientific Research (2005-06, EU 13.600=)

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for the entries related to the vocabulary of symbolic, hybrid and monstrous animals, as part of a research work of national interest (PRIN) in alliance with Siena, Turin and Palermo. In the past, GRIMM relieved upon a smaller funding stream, allocated by Fondazione CRTrieste (2004, EU 2.000=). Currently, GRIMM is seeking funding for postdoctoral grants that will allow us to finish the translation of DEMGOL into English and Portuguese, to enrich the iconographic apparatus and to complete the editing of numerous other entries on minor mythological characters, which will soon number over 1000. GRIMM is a not-for-profit endeavour, and is intended to involve young scholars and students in collaborative, interdisciplinary research projects promoting the popularization of European culture and distance learning.

Images:

Figure 1. The ephebe of Losinj (Apoxyòmenos)

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Figure 2. Canis Minor

Figure 3. Cetus: fresco of Villa Farnese in Caprarola (Viterbo)

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BUILDING UP AN ARCHAEOLOGICAL RESTORATION & CONSERVATION DEPARTMENT IN FRIULI-VENEZIA GIULIA FULVIA LO SCHIAVO *

1. Foreword The application of “hard sciences” to archaeology and in general to cultural heritage is certainly not a new topic, since the National Council of Research (CNR), due to the initiative of Luigi Donato, dedicated in the Fifties an Institute to Le Scienze Sussidiarie dell’Archeologia (“Sciences subsidiaries to Archaeology”). From this pioneering period onwards, the CNR Institute enhanced his activity not only following all fields of Cultural Heritage (the present name is: Istituto per le Tecnologie Applicate ai Beni Culturali, “Institute for Technologies applied to Cultural Heritage””) but also interlacing and optimizing the research, according with the new discoveries and orientation of Cultural Heritage and its conservation, improvement and opening to the public. From this point of view, to interconnect the “hard science” to the peculiar situation of Friuli-Venezia Giulia Cultural Heritage – and particularly to archaeology, is a basic necessity. Many of the original themes identified of this International Conference are, right in this moment, under the highest attention and immediate application of

*

At the time of the Conference, the present author was acting Superintendent of the Archaeological Heritage in Friuli-Venezia Giulia, at the same time having the main responsibility in Tuscany. In April 2008 this interim assignment was suspended. Nevertheless, since this paper was officially delivered at Velj Losinj and is based on experiences matured both in Tuscany and in Friuli-Venezia Giulia, it is correct to keep the original text. I am greatly indebted to the restorers of Friuli-Venezia Giulia Superintendence: Antonella Crisma and Luisa Zubelli, Daniele Pasini and Gianni Gallet, and to Franca Maselli Scotti, former acting Superintendent, Director of Aquileia Museum and territory, responsible for Archaeological Heritage in Trieste and Gorizia provinces, excellent archaeologist and great friend.

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the Soprintendenza per i Beni Archeologici (Superintendence for Archaeological Heritage) of Friuli-Venezia Giulia, among which: 1. MARINE ARCHAEOLOGY, including the problem of waterlogged wood and the restoration of any handmade object recovered from under water; 2. ANALYSIS & RESTORATION OF ANCIENT BRONZES AND METAL MADE OBJECTS; not to forget mosaics, stucco works, glass and fayence objects, pottery, and so on; 3. ENVIRONMENTAL & CLIMATIC IMPACT ON CULTURAL HERITAGE, including the problem of conservation in the sites chosen for the exhibitions; 4. SCIENCE FOR GREEK AND ROMAN ARCHAEOLOGY IN THE EASTERN ADRIATIC. 5. It is also necessary to add SCIENCE FOR PREHISTORIC AND PROTOSTORIC ARCHAEOLOGY IN THE EASTERN ADRIATIC, highly important because less self-protected and in worst conditions of conservation for the stratification of centuries of life and use of the site. 6. MOBILE LABORATORIES FOR CULTURAL HERITAGE ANALYSES, and many other matters. The natural conclusion from these premises, taking advantage by all possible interconnections and acquired experience, is to trace the outline of an Archaeological Restoration and Conservation Department for the Friuli-Venezia Giulia region and, here, to present a project of high and mutual interest, from the points of view of the human sciences, of the hard sciences and also of the enjoyability by the people and by the tourists.

It is evident that there are too many things to say to such a stimulating audience. Therefore, after many positive discussion with my dear friend and colleague Manuela Montagnari, I selected one single aspect that summarizes all the others. Now I’ll explain my point and then I’ll illustrate it through many examples. 2. The point Science and archaeology = equal = conservation, restoration and management

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Archaeology is the science investigating the past. = equal = Archaeology is a Science-based discipline About the difference between “hard” and “soft” science, there is not much to say: it is out-of-date, based on “ignorance” and must be totally revised. “Human” science is a far better term than “soft”, but “human” do not include ancient history and archaeology, that are true sciences, in the investigation and in the reconstruction of the past: the best comparison is medical science methodology: working on the basis of diagnosis, prognosis, therapy and deriving prophylaxis. On the contrary, without science, we are in the domain of invention, romance, legend, that we all appreciate, while reading a relaxing book, but that we are not discussing now and that cannot be accepted in the field of conservation of our precious Cultural Heritage. There are two “chains” of actions: the “Discovery Chain” on the field, that is mostly archaeology and that is not going to be discussed here, with the exception of its consequence: Survey/Discovery, Excavation, Documentation, Diagnostic, Restoration and Conservation, leads to: the Culture of Management. The second chain is the “Exhibition Chain” in the Museum: Documentation, Diagnostic, Restoration, leads to: the Culture of Management. Both “chains” lead to the Culture of Management. “Management” is a stronger word than the Italian manutenzione (“maintenance, upkeep, care”) and an unfortunately highly despised idea – and practice –, that implies cleaning, checking and monitoring, in the broader sense, the state of health and/or disease of the cultural heritage: using a medical work, this is prophylaxis. It is evident that a negligence in the field of prophilaxis is cause of illness and ultimately of death, for human beings as well as for monuments and objects. Paola Pelagatti (Pelagatti 1994), former responsible of Southern Etruria Superintendence invented this concept, and Giorgio Bonsanti (Bonsanti 2004),

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former director of the Opificio delle Pietre Dure in Florence wrote recently a short important paper on the subject. Archaeology as a Science-based discipline do not allow to select at random the object of an action, of a study, of a research: the statistical base and the population behavior are essential before any selection and all along any intervention. On the contrary, the criteria of selection of a work of art for restoration/ conservation is mainly based on its age, value, importance of the author, its meaning in the history of art and also in the history of a place and of a social group. It is looking after the excellence that the selection is made and not on the basis of a context. The archaeological method of restoration/conservation, aiming to understand the whole and operating only in consequence of a full analysis, as well as a doctor in front of a sick person, follows in some way an opposite method with respect to the uniqueness of a work of art. 3. Publication. Archaeology and restoration/conservation, as any other Science-based discipline, need careful studies, notes, experiments registered, written and published. Publication are due both to scientists and to the broad public, on the principle that everybody needs to know and that no discovery is such if nothing is not thoroughly explained. This wide argument is not going to be discussed here (Lo Schiavo 2006). 3.1. Examples in Tuscany: 3.1.1. Archaeological Research nowadays: the example of the Etruscan Sanctuary of Poggio Colla-Vicchio (Firenze). Archaeological research on the site of Poggio Colla is going on successfully since many years, lead by P. Gregory Warden, of the Southern Methodist University of Dallas, author of many studies, papers and volumes (Warden 2008 with previous bibliography). The exciting results of the research concern a rich Etruscan sanctuary on the acropolis, where a temple was built near a natural crevice and hundreds of offerings made of gold, iron, bronze, stone and pottery were buried and scattered all around.

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As an example of field survey in extension the research through a new magnetometer was used on the nearby site of Podere Funghi, where in 2000 an Etruscan furnace had been located, but the discovery of many pottery sherds on the ground suggested the idea that other similar structures should be present. The magnetometer, needing only regular rows of small superficial holes to insert the bar of the apparatus, enables to check quickly and cheaply wide extension of land (Warden 2007). At Poggio Colla, the traditional methods of excavation are coupled with the highest sophisticated technologies of documentation. A field laboratory is run in parallel with the excavations, assisted by the specialists of the Conservation/Restoration Centre of the Superintendence for Tuscany Archaeological Heritage in Florence, through the close collaboration of the Superintendence archaeologist responsible for the territory of Mugello, Luca Fedeli, allowing the participation and training of the students. 3.1.2. Il Cantiere della Navi di Pisa e Centro di Restauro del Legno Bagnato (“Pisa Ancient Ships Yard and Restoration Centre of Waterlogged Wood”). The archaeological research at S. Rossore-Pisa, where a heap of wrecks and other remains (up to now about 30) dating from VIth BC to VIIth AD were discovered, are by now a well known subject: an archaeological non-stop enterprise from the excavation to the restoration/conservation of all finds (Camilli 2006 with previous bibliography). To discuss at length the pioneering techniques of conservation of waterlogged objects, not only wood, but also basketwork, metal objects, pottery, and so on, would be a perfect topic for a second International Conference in the framework of Archaeology = equal = Science, but exceedingly wide; in many occasions there were anticipations on these subjects (Camilli a cura di 2004). It is important to stress that the archaeological enterprise works from the very beginning in connection with at least 20 different scientific institutions and universities in Italy and in Europe: Istituto Centrale del Restauro (ICR-MiBAC) Roma; Scuola Normale Superiore, Pisa; ARCO, Laboratorio di archeobiologia, Museo Civico di Como; Dendrodata s.a.s., Verona; Istituto per la Conservazione e Valorizzazione dei Beni Culturali (ICVBC) CNR, Firenze; Istituto per la Valorizzazione del Legno e delle Specie Arboree (IVALSA) CNR, Firenze; Dipartimento di Archeologia, Università di Pisa; Dipartimento di Agronomia, Università di Pisa; Dipartimento di Chimica e Chimica Industriale, Università di Pisa; Dipartimento di Scienze e Tecnologie Forestali e Ambientali, Università di Firenze; Dipartimento di Agronomia, Università di Genova; Dipartimento di

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Scienze della Terra, Università di Firenze; Istituto per le tecnologia applicate ai Beni Culturali (ITABC) CNR, Roma; Insegnamento di Archeologia Marittima, Università di Roma III; LENS, Firenze; Escuela Española de Arquelogìa, Roma; Museum für Antike Schiffart, Mainz; NucleArt, Grenoble (Camilli …; the updating on the activity of the Restoration Centre for the Waterlogged Wood can be found in the site http://www.cantierenavipisa.it and on the on-line review Gradus). The Restoration Centre for the Waterlogged Wood is originated by the Conservation/Restoration Centre of the Superintendence for Tuscany Archaeological Heritage in Florence, working particularly since 1966 on an international level and responsible for exceptional exploits, such as the restoration of the Riace bronzes, the Cartoceto bronzes (Rastrelli 2006) and, recently, the Amazons Sarcophagus (Bottini, Setari a cura di 2008) and the Minerva from Arezzo (Cygielman, a cura di, 2008). Another important department is the Archaeoanthropology and Archaeozoology Laboratory (Pacciani 2008). 3.2. The Restoration Laboratory at Aquileia. Aquileia is a world by itself. A great Roman town, a true capital in the north of Italy, rich and important for cultural level, trade connections, works of art, roads, aqueducts, splendid public and private buildings decorated with mosaics, stucco and sea-shells decorations and moreover with statues, fountains, inscriptions. Since the very beginning of the archaeological research, restoration/conservation was a non-stop enterprise. The site where the analyses and conservation techniques take place is an elegant two-storied house, in the same complex and within the same enclosure of the Archaeological Museum, following the two cloisters where the mosaics and epigraphs are exhibited, in front of the manager’s and administrative office of the Museum and of the Archaeological Park. It is large enough and displays appropriate equipment to allow a lively activity. In time, the mass of objects duly restored exceeded the dimension of the Museum cases and also exponentially grew what we use to call “the second choice Museum” (Museo di seconda scelta), a wide deposit where the objects are set side by side, at the students’ and scholars’ disposal. Actually, in the Restoration house of Aquileia there is material enough to fill up not less than three Museums. The main problem is that, considering that findings go on without interruption, mostly because of rescue excavations happening day by day, since the modern town of Aquileia overlays the Roman colony, not to forget the Forum restoration, which means at first the complete excavation of the area and

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of the foundations of the structures, the few restorers – though excellent – are unequal to the huge task. We are speaking of four persons, one of which is mostly attending a local political appointment, and only one of a high specialization level. In consequence, they are working on various materials: pottery, glass, metals, stones, but their best accomplishment, about which they acquired a notable renown, are the mosaics. 3.3. The Restoration Laboratory at Trieste. Three restorers are active in Aquileia and only one in Trieste, highly specialized, mostly dedicated to pottery but also working with good results on mosaics, and attending to the conservation and management of the many archaeological sites existing in the town. The Laboratory is housed in the rich and well equipped kitchen of the Palazzo Economo, an elegant middle class residence, where from the beginning all the Superintendences of Friuli-Venezia Giulia and later on also the Regional Direction for Cultural and Landscape Heritage is located. A second smaller Laboratory is dedicated to the works of art and a second bigger one is in Udine. The kitchen of Palazzo Economo is an interesting and well preserved XVIIIth Century example with porcelain stove and decorated walls, and with a copper and iron oven, more a museum room than a modern laboratory for conservation. 3.4. The Restoration System. It is evident that four restorers, in a building packed up with archaeological materials and an historical kitchen are not enough to ensure the restoration/conservation of the Archaeological Heritage of Friuli-Venezia Giulia, mostly because this heritage is growing early through the planned excavations under the direction of the Superintendence archaeologists and through the excavation “in concession” (in concessione) under the direction of the different Italian and foreign Universities archaeologists (Lo Schiavo, a cura di, 2008). On the other hand, in Villa Manin at Passariano (Udine) there is a Regional Restoration and Cataloguing Centre. At the moment, the more developed specialization is dedicated to paper, books and bindings restoration, through a High Training School, while to archaeology is dedicated mainly a cataloguing activity.

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The ideal project would be to join the two institutions in order to build up a new strengthened system, a “Restoration System”: 1. 2. 3.

4. 5. 6.

new wide deposits to house the archaeological materials as it is discovered, where to carry out the diagnostic activity; in the same site, also first aid and planning of specialized restoration activity can be made; distribution of the materials to different specialized laboratories in the Region, in Italy or abroad if necessary, according to the kind of material and state of preservation; parallel training of students from different Universities and parallel archaeological cataloguing; temporary or permanent exhibition of the results in local museums; parallel popular and scientific paper- and digital- publications.

The Restoration System should be accessible to various Superintendences and to various Universities, according to different projects, followed and shared, step by step by the scientist, taking advantage by the possible applications to experiments to various materials. Financing should be participated by the Ministry for Cultural Heritage and Activities, the Region Friuli-Venezia Giulia, the Provinces, the local municipalities interested in the conservation and exhibition of their heritage, bank or banking association and a system of sponsorships, local industries and firms. Sponsorship and administration should be autonomous, guaranteed by banks or banking associations acting as treasury for the investors. If necessary, the Restoration System can become a Foundation. Even if I do not minimize the difficulties, I am convinced of the practicability and feasibility of this ideal: let us hope that somewhere and somehow, at least as an experiment, can develop and grow up, to the advantage of the Archaeological Heritage.

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RELATIVE SEA LEVEL CHANGES BY USING ARCHAEOLOGICAL MARKERS: THE INTERREG ITALIASLOVENIA PROJECT "ALTO ADRIATICO” * STEFANO FURLANI DiSGAM, Università degli Studi di Trieste,via Weiss 2 34127 Trieste, Italy FABRIZIO ANTONIOLI ENEA, Special Project Global Change, via Anguillarese 301 00660 S. Maria di Galeria, Rome, Italy RITA AURIEMMA Dipartimento Beni Culturali, Università degli Studi di Lecce, via D. Birago 64 73100 Lecce, Italy Six submerged archaeological sites located along the NE Adriatic coast (Italy, Slovenia and Croatia) and dated ~2.0 ka BP were studied. In particular, we provide new precise measures measured with respect to the present sea level of submerged archaeological and geomorphological markers (notches), that are considered good sea level indicators. The interpretation of their functional heights, related with sea level at the time of their construction, allows to obtain data on the relative changes between land and sea. These data have been compared with the predicted sea level rise curves, using new mathematical models for the glacio-hydro-isostatic contributions associated with the last deglaciation. The northeast Adriatic (Italy, Slovenia and Croatia) is an area of subsidence and we use the calibrated model results to isolate the isostatic from the tectonic contributions. This indicates that the Adriatic coast, from the Gulf of Trieste to the southern Istria, has been tectonically downlifted by no less then ~ 1.5 m since Roman times.

1. Introduction Sea-level change is the sum of eustatic, glacio-hydro-isostatic and tectonic factors. The first is global and time-dependent, while the other two vary according to location. The glacio-hydro-isostatic part along the Italian coast was recently predicted and compared with field data, at sites not affected by significant tectonic processes [48]. The aim of this paper is to provide new data on geoarchaeological and geomorphological markers to study the relative sea level rise during the late *

This research has been partly funded by the EU Project Interreg IIIA, Phare CBC Italia–Slovenia.

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Holocene along the coastlines of North-eastern Adriatic (Slovenia, Croatia and Italy) surveyed in the Interreg IIIA Italy-Slovenia Project. Archaeological and geomorphological indicators represent a powerful source of information from which the relative movements between land and the sea can be evaluated. Archaeological evidence in micro-tidal areas, such as the Mediterranean Sea, can provide significant information for the study of relative sea level changes during historical times. Ancient coastal structures require a precisely defined range of functionality related to the sea level at the time of construction. Slipways, fish tanks, piers and harbour constructions, generally built before ~2 ka BP, provide a valuable insight of the regional variation in sea level in the last 2000 years [48, 49 and references therein]. Quarries carved along the coastlines and located near fish tanks and harbours or villas of the same age can provide additional data, both on the past water level and on their own functional elevation above sea level, although the quarries are not very precise indicators [24]. In this paper, we examine archaeological evidence from the North-eastern Adriatic coasts (Italy), where the development of maritime constructions reached its greatest concentration during the Roman times and where many well preserved remains are still present today. The best preserved sites were examined providing new information on their relations to the mean sea level in the I century A.D. Isostatic and tectonic contributions to this change are estimated from observational and model considerations to establish the eustatic change over this period. In addition we present new data on late Holocene sea level and on the vertical rate of tectonic movements in the Gulf of Trieste (Italy), in Slovenia and Croatia (Fig.1). These provide a key for the understanding of the geodynamic evolution of the Mediterranean basin. Unpublished archaeological markers such as docks, piers and pavements (all presently submerged), and geomorphological markers, such as core stratigraphy, as well as tidal notch data, were used as benchmarks recording the relative vertical motion between land and sea since their construction or formation. The heights of the selected archaeological markers were measured with respect to the local sea level. The interpretation of their functional heights provided new evidence on the changes. These data, together with their relative error estimation (elevation and age), were compared with predicted sea level rise curves using a new prediction model for the Mediterranenan coast. This model consists of a new esl function (the ice-volume equivalent sea level change, [43]) that assumes a small continuous melting of the Antarctic ice sheet until recent times. The accuracy of these predicted values is a function of the model parameter’s uncertainties defining the earth response function and the ice load

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history (esl). This new model is more accurate if compared to the previous one by [48], especially in northern Italy, because of the inclusion of an Alpine deglaciation model [50] and because of improved Scandinavian and North American ice sheet models [51]. The results provide new data on the sea level rise and tectonic rates in the North-eastern Adriatic coast during late Holocene. 2. Geodynamic setting The Alpine Mediterranean region marks the broad transition zone between the African and the Eurasian plates and its tectonics are a result of the evolution of the related collisional plate boundary system [52, 33, 21]. Thus, the geodynamics of this region are driven by lithospheric blocks showing different structural and kinematic features including subduction, back-arc spreading, rifting, thrusting, normal and strike slip faulting [53, 59, 60]. The recent dynamics of the region are shown by the distribution of seismicity that outlines the plate boundaries and the quasi-aseismic domains such as the Adriatic and Tyrrhenian areas. These areas have been interpreted as rigid blocks or microplates or as undeformed sedimentary basins, limited by lithospheric-scale structures such as subduction fronts and large strike slip fault systems [20, 70]. Instrumental and tectonic data show a complex deformation pattern related to the kinematics of the Adriatic region, which has been interpreted as a block (Adriatic block) that is independent -or partially independent from the African plate [1, 80, 79, 63, 62]. Although this region displays an active deformation and its kinematics are still debated, interpretations of recent GPS observations considered this area as a unique crustal block rotating counter-clockwise [72]. This block moves independently from the African plate and displays a NorthSouth shortening in the central and eastern southern Alps at 1-2 mm/a and a northeast-southwest shortening between 1.6 and 5 mm/a along the Dinarides and Albanides. A comparison between the motion predicted by the rigid-rotation of Adria and the shortening observed across the area of the largest known earthquake that struck this region (the 1976 Friuli earthquake) suggests that the 2.0 ± 0.2 mm/a motion of Adria is absorbed in the southern Alps through thrusting and crustal thickening, with very little or no motion transferred to the north, and a northward-dipping creeping dislocation whose edge is located within a 50 km wide area beneath the southern Alps [17]. The geological features of the region is characterized by a thick carbonatic succession dating from Upper Jurassic in the Central part of the Istrian peninsula to Lower Eocene, which continued during the Lower-Mid Eocene with turbiditic flysch deposits [16, 77, 31].

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3. Recent movements Along the North-Eastern Adriatic coast the MIS 5.5 geomorphological marker does not outcrop [22]. These deposits, which have been observed in boreholes between 85 and 117 m below sea level in the northern Emilia-Romagna region, provide evidence that a significant tectonic subsidence occurred during the last 125 ka. The amount of the subsidence rates, however, is not straightforward, since large uncertainties exist both in terms of age and position of the paleoshorelines of the sampled deposits. Given all the above uncertainties, subsidence at a rate of ~1.0 mm/a can be estimated for this area. Two further sites located in the northern Adriatic (Veneto and Friuli), display lower subsidence values (-0.7 and -0.2 mm/a [22]) with respect to those markers located in Emilia Romagna, being located close to the Po Plain, thus witnessing a crustal flexure due to the Southern Alpine and Dinaric contraction. Pirazzoli [60] surveyed some sites in southern Istria and northern Croatia, which display a well developed notch at -0.5/0.6 m, while Fouache et al. [25] extended the investigations to Northern Istria, finding archaeological and geomorphological markers at around the same depths and related to some Roman age remains as well as to submerged notches. Lambeck et al. [48] summarized late Holocene data for the Emilia, Veneto and Friuli coastal plains using lagoonal markers sampled and dated in cores at different depths. The results show tectonic subsidence with lowering values from west to east at 1.1, 0.45, 0.37 and 0.28 mm/a. Benac et al. [5] have provided a detailed description of marine notches between -0.5 and -1.0 m in the Gulf of Rijeka, possibly downward displaced by the co-seismic deformation occurred during an earthquake around 1000 years BP. 4. Materials and Methods 6 archaeological markers and several tidal notches were surveyed along the North-eastern Adriatic coast (Table 1). The surveying involved four steps: measurement, correction, error bars and comparison. Measurements of the elevation of the submerged archaeological markers with respect to the local sea level at the time of survey. Values reported in Table 1 are the mean values of multiple measurements collected in correspondence of the best preserved parts of the investigated structures. Correction of surveyed data via the Trieste tide gauge data collected at the time of surveys. Data are reported in Table 1. Error bars for the elevations and age values of the archaeological markers have been provided. Their functional heights have been evaluated on the basis of accurate archaeological interpretations provided by the staff of archaeologists. Age errors have been estimated from the architectural features; elevation errors have been

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derived from the measurements, corrections and estimation of the functional heights (Fig. 2). The comparison of predicted and observed sea levels sea level elevation predicted by the new Lambeck model with respect of the current elevations of the markers (i.e. the relative sea level change at each location). At the sites where the elevations of the markers are in agreement with the predicted sea level curve, we hypothesized tectonic stability of the locality. On the contrary, when the elevations of the markers differ from the predicted sea level curve, we hypothesized that the area is subjected to tectonic subsidence.

A Site name

B Coordinates

C Survey date (yyyy/mm/dd, h)

1 Stramare

45°36'07'' 13°47'24'

2005/07/16 h 13:40 GMT

2 Punta Sottile

45°36'08''' 13°43'10'' 45°35'34'' 13°42'53'' 45°31'57'' 13°38'41'' 45°29'59'' 13°30'13'' 45°29'59'' 13°30'13'' 44°54'40'' 13°46'29'' 44°54'39'' 13°46'35''

2005/05/25 h 19:55 GMT 2005/11/10 h 15:10 GMT 2004/10/26 h 10:30 GMT 2005/10/17 h 13:00 GMT 2005/10/17 h 13:30 GMT 2004/10/27 h 12:30 GMT 2004/07/05 h 14:20 GMT

3 Jernejeva draga San Bartolomeo 4 Sv. Simon San Simone 5a Savudrija/Salvore 5b Savudrija/Salvore 6a Briunj 6b Briunj

D E Type and Archaeolo measured gical age height (m) (yr BP) Walking 1900±100 surface, -1.66 Pier, 1950±50 -1.65 Vivaria 1900±100 dock, -0.70 Pier, 1950±50 -1.40 Pavement, 1950±50 -1.18 Pier, 1950±50 -0.10 Pavement, 1950±50 -1.20 Dock/Pier, 1950±50 -1.10

F Tide (m)

G Corrected Height (m)

+0.06

-1.60

H Functional height (m) 0.0 a.m.s.l.

I s.l. change (m)

References

+0.25

-1.00

-0.10

-0.80

+0.40

-1.00

-0.32

-1.50

-0.40

J

-1.60 ± 0.60

This paper

0.60 a.m.s.l.

-1.60± 0.60

0.60 a.m.s.l.

-1.40 ± 0.60

Auriemma et al. (2007, in press) This paper

0.60 a.m.s.l.

-1.60± 0.60

Degrassi (1957)

0.0 a.m.s.l.

-1.50 ± 0.60

This paper

-0.50

1.00 a.m.s.l.

-1.50 ± 0.60

0.00

-1.20

0.60 a.m.s.l.

-1.80 ± 0.60

+0.10

-1.00

0.60 a.m.s.l.

-1.60 ± 0.60

Fouache (2000) and this paper Degrassi (1957) Fouache (2000) Degrassi (1957) and this paper

Table 1. Measurement data and inferred sea levels for archaeological sites in the NE Adriatic region. A: Site names and numbers and the latter are also shown in Fig. 1. B: WGS84 coordinates of the surveyed sites. C: Year, month, day and hour of measurement. D: Field measurements (before correction). E: Age of the archaeological sites. F: tidal correction applied for tide amplitude at the time of surveys. Tide values at each location are computed with respect to the Mean sea Level of Genova, using data from the local reference tide gauge data of Trieste, which are the archaeological sites nearest to the permanent stations, and including tide time delays at each site. G: Corrected elevation of archaeological structure surveyed as derived from data in columns D, F and G. H: Functional height of the marker used with respect to mean sea level. I: Estimated relative sea level change. Errors are within the tide amplitudes of ± 0.60 m for the Adriatic sea. J: References. For more information about the tide gauge of Trieste, also see http://www.univ.trieste.it/~dst/OM/OM_mar.html

Elevation measurements -with respect to the current sea level at the time of the surveys- were performed through the use of optical and mechanical methods (Salmoiraghi Ertel automatic level or invar rod). All the measurements of the archaeological features’s depths were made in times of low wave action and they were related to the sea level position for that particular moment. Since the investigated archaeological structures (fish tanks, harbours, piers) were used year-round, we assumed that the defining levels correspond to the annual mean conditions at the time of construction. The measurements are therefore reduced to the mean sea level applying tidal corrections at the surveyed sites, using the data of the nearby tide gauge at Trieste. Elevation measurements are given [76]

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with respect to the Italian reference plane network of the Istituto Geografico Militare (Genova Mean Sea Level 1942, [27]). The estimation of the tide amplitudes and their correction is a crucial element for the northern Adriatic sea; the measurement of the markers’ elevation must be properly corrected for tides, as they here show the largest values in the whole Mediterranean basin (up to ~1.8 m and mainly produced by meteorological variability in a closed basin, as opposed to the normal values of max ~0.45 m , from the Tidal Data Base of the Italian Istituto Idrografico della Marina). For the above mentioned reasons, local tide amplitudes were also estimated using data from the nearby permanent tide gauge located in Trieste (recording since 1890). In order to estimate the sea level change in each location, and to compare the observed results in different locations, we defined the functional heights of the archaeological benchmarks. This parameter is defined as the elevation of specific architectural parts of an archaeological structure with respect to an estimated mean sea level (tidal sea level) at the time of their construction. It depends on the type of structure, on its use and on the local tide amplitudes. Subsequently, functional heights also define the minimum elevation of the structure above the local highest tides. To improve the interpretations, we also measured the functional heights at some modern harbour structures (piers and docks) located along the coasts of the Gulf of Trieste, comparing them with those measured at the archaeological sites located in the nearby areas. For example, we assumed that the pavements at the top of the piers were in the range 0.5/1.0 m above sea level. Subsequently, as the tide amplitude is up to ± 0.9 m in the Gulf of Trieste, during particular meteorological events, the top surfaces of some small piers or docks can be nearly submerged during maximum tides. On the other hand, the seafloor in some basins can become dry during the lowest tides. It is worth noting that the architectural features and functional heights of modern piers and docks are in agreement with those of Roman age. This information can also be deduced from previous publications [23, 24, 32], from historical documents (Vitruvius, [32]), from the remnants of Roman age shipwrecks (which provided data on the size of the ships or boats and their draughts [69, 75, 14] and through rigorous estimation of the functional heights of the piers, by using and interpreting different type of markers on the same location [49]. As far as we know, navigation during Roman times was mainly seasonal (mare clausum from October to March) and the Roman ships that used these coastal structures had draughts of ~0.5 m, which fit the features of the observed archaeological markers. The use of these structures, their age and

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conservation, the accuracy of the survey and the estimation of the functional heights were all used in considering the observational uncertainties at each site. 5. Data The archaeological sites we surveyed were already known by the scientific community, although most of them have never been used before for geomorphological studies and they had not been surveyed using direct underwater observations. Since this is a critical point for a rigorous estimation of the relative sea level changes based on archaeological markers, surveys were performed to provide new and affordable data for our geophysical and geomorphological goal. 5.1. Geomorphological markers The North-eastern Adriatic coast is the result of the Holocene submersion that was largely completed about 7 ka calibrated (cal) BP. Afterwards, the sea level rose only slowly up to the current elevation. With the exception of storm or tsunami deposits found nearby Pula [2] at an elevation of about +0.7 m, along the North-eastern Adriatic coasts, no marine notches or fossils have ever been found at elevations higher than the current sea level. Tidal marine notches are considered to be good markers of coastal tectonic movement. Pirazzoli [67]observed submerged marine notches in Croatia at ~-0.6 m and Fouache et al. [25] studied and measured some submerged notches along the Istrian coast at the same altitude. These notches have been attributed to Roman age. Benac et al. [5] measured the submerged notch on the Gulf of Rijeka at a depth between -0.5 and -0.6m and in Bakar Bay between -1.03 and 1.15m (Fig. 3). These Authors measured notch depth with respect to the local Biological Mean Sea Level and they ascribed the recent position of the notches to rapid coseismic subsidence following an earthquake in AD 361. In view of these observations and with the aim of providing new measurements on the whole NE Adriatic area, we surveyed the Northern limestone coast of Istria and the Gulf of Trieste (Italy), providing high-density measurements. South of this area, further data were collected in the Kornati islands of southern Croatia as well as in Montenegro (Fig. 3). If we take a close look (east to west) at the the Gulf of Trieste (Italy), we observe that at Miramare there is a well carved notch at an elevation of -0.6 to 0.8 m (tide corrected). Only ~6 km west from Miramare, its elevation increases to -0.9 m. Between Sistiana and Duino (Italy), toward North-west, the depth of the notch continues to increase from -1.3 m, going down to -2.5 m, as measured at six different locations (Fig. 3). In accordance with the local tide

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amplitudes (the highest in the whole Mediterranean sea) the width and amplitude of the notch are ~1 m (with a well defined tidal notch shape (Fig. 4). Unfortunately, biological organisms have not been preserved, preventing dating of the notch. A submerged tidal notch [67, 25, 5] runs south of the previously described one along the coastlines of Istria and Croatia at an average elevation of -0.6 m. South of the Gulf of Rjeka, towards Montenegro, the present day tidal notch was not observed. A submerged notch was instead found at an altitude of about -0.5 m. Fig. 3 illustrates this notch’s distribution and elevation. Our observations show that the present day notch is absent along the limestone coasts of the Northeastern Adriatic, between Duino (Italy) and Kotor (Montenegro), while a submerged notch was observed at about -0.6 m below the present day sea level. 5.2. Archaeological markers In addition to the above mentioned gemorphological markers, descriptions and data were also provided for seven coastal Roman age archaeological sites (see Fig. 1 and Table 1) that were well related with sea level. 5.2.1. Stramare (Muggia, Trieste) At Stramare, near the Ospo Stream mouth, the terrace behind the narrow beach is characterized by many traces of protohistoric and Roman habitation, found despite the damage caused by the modern industrial district [9, 10, 11, 12, 54, 55, 64, 65, 66, 81]. The lower terrace continues below the current sea level. In ancient times, the terrace was a land extension protecting the left side of the Ospo Stream mouth. Probably, the pars rustica or the pars dominica of a maritime “villa” once faced this open area. On the west side, this terrace was contained by a wall that was very similar to the emerged ones. The upper side of this wall is currently 1.6 m above the present day sea level (Table 1). The wall was built with thick stone slabs laid facing the ground with its foundation 0.5 – 0.6 m under its actual upper surface. At the time of its construction, the wall’s foundation level, now at 1.66 m below the sea level (-1.60 corrected for tide, pressure and wind), would have emerged at least for part of the day. On the northern and eastern sides, the terrace slopes down to 3.0 m: this elevation difference most likely marks the old seashore, and it is sheltered by large stone blocks, some close together, some scattered. Shards of amphorae and common ware of Roman imperial age occur in this submerged terrace but it’s difficult to establish this building’s chronological range and its use (Fig. 5 site 1, Table 1).

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5.2.2. The pier at Punta Sottile SW (Muggia, Trieste) The Punta Sottile Pier was discovered in the 1980s [28, 29, 81, 61, 13] and it was recently excavated. The structure lies 40-50 m off the coastline. The first portion of the pier is made up of blocks belonging to the shore platform that, in this area is very regular such that the break lines could be wrongly interpreted as an artificial structure, and, partially, it is composed of cut blocks arranged and flanked in the areas where there is no shore platform (Fig. 5 site 2). The pier is 12 m long from its foot and 2.5 – 2.6 m wide. It was built with the so called “a cassone” technique, typical of the landing structures of the Eastern Adriatic Sea. Its façade is made of opus quadratum, with large 3 m long parallelepiped sandstone blocks containing a nucleus made of rubble and joined (in places) by transverse blocks. There are two overlapping layers of blocks: the first one is placed on a foundation that follows the marly shore platform. The foundation is made of a small heap of stones, pebbles, ceramic shards; the last of which allowed a safe dating of the time of pier construction, i.e. back to the central decades of the Ist century A.D. The sea-bottom is 1.1 m and 2.2 m deep at the pier foot and at its head, respectively, slowly sloping westwards, whereas the actual upper pier surface lies on a sub-horizontal plan between 1.15 m and 1.4 m. We hypothesize the former existence of a third layer which would have resulted in a near horizontal surface of the pier that joined the shore platform behind it (Fig. 5 site 2). This leads us to the assumption that the original pier depth was about 1 m, while the walking surface was possibly between at 1.1-1.0 m. If we therefore add the initial depth of -1.65 m (corrected to -1.00 m) to the functional height, the data corresponding to the relative sea level rise equals to 1.60±0.60 m (Fig. 5 site 2, 9A). 5.2.3. Jernejeva Draga/San Bartolomeo (Ankaran, Slovenia) A large fishery was discovered and excavated (this paper) in the S. Bartolomeo bay, situated very close to the Italian-Slovenian border [37]. The structure is composed of two large docks and most probably a pier. Its total length is 135 m, with a width of 50 m, while the west side is 80 m long. The docks are today contained in an embankment made of disconnected stones, but in Roman times the embankment probably had façades, at least on the inner side. Its eastern side is the main sea level indicator: it is an embankment for the eastern dock, a pier and a quay at the same time. Its shape is arched, but its foot is straight, 30 m long and 2.6 m wide. The pier has two (external) façades built near the close by stone blocks and the rubble of heap of stones. The actual pier surface seems to have lost one or two rows of blocks since its construction and if two large fallen blocks on the north side are placed one over the other are indicative of the

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elevation of the ancient walking surface at -0.7 m which corrected (-0.80 m) and added to the functional height (0.60 m) indicates a sea level rise of 1.40 m (Fig. 5 site 3, Table 1). The suggested age of the S. Bartolomeo fishery is the beginning of the Imperial Age because of its analogy with other similar structures and of the amphora shards found between the stones of the embankment (Fig. 5 site 3). 5.2.4. Sv. Simon/San Simone (Izola, Slovenia) The splendid structures of the S. Simone bay “villa” and its harbour (the largest one on the Istrian coast and measuring over 8000 square metres) have been well known since the 16th century AD. Unfortunately, these structures were filled with concrete in the last decades [18, 19, 73, 74, 75, 7, 41, 6, 36, 57, 37]. The building includes a quay, a pier, a breakwater and other working areas. The pier starts from the South-west quay corner and is today only visible in the foundations of the modern wharf. The pier is 55 m long and 2.5 m wide and, in different stretches, it shows three layers of large (~2 m long) yet differently sized stone blocks. The lower layer is larger, in accordance with the Vitruvian construction rules, and on its upper layer, large mooring rings were probably placed, as recalled by the 19th and early 20th century observers. Today, the pier surface lies at a corrected height of -1.0 m and if the functional height was at least ~0.6 m, a sea level change at an average value of ~1.60 m can be estimated. The archaeological findings from the excavations at the “villa” allow us to date the most important habitation phase as being the 1st and 2nd centuries AD (Fig. 5 site 4). 5.2.5. Savudrija/Salvore (Croatia) The bay is sheltered by two large piers stretching out from opposite seashores. The 1990s excavations allowed us to conclude that the piers were built with large local stone blocks to protect the quay, which was 70 m long. Two inscriptions - one of which was dated back to the first half of the 1st century AD - were retrieved from the harbour area. These inscriptions suggested the presence of many buildings, both residential and commercial [19, 39, 40, 34, 56]. We collected measurements from two different areas: the first is an underwater terrace, in front of a quite well-preserved building standing on the beach (the so called cistern); the terrace is contained by quite large blocks lying on the shore platform at a corrected height of -1.50 m. Neither the function nor the date of this terrace are known. We assume that it was a shipyard or other functional working area connected with the buildings behind it and emerging above sea level only sometimes during the day. The second measurement is

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from the southern pier which was built “a sacco”, i.e. with walls of large overlapped blocks in several layers (up to three conserved in the inner side) and stone rubble within it; this pier is higher than the others and it is located at a corrected height of -0.50 m below the present day sea level. For this 51 indicator, we estimated a functional height of at least 1 m above sea level, because it was probably a breakwater built to protect the inner basin of the harbour. Thus, a functional height of 1 m can be estimated as a minimum value (Fig. 5 site 5). 5.2.6. Brijuni/Brioni (Croatia) On Brijuni island in Verige Bay (Val Catena) lies the archaeological area of a splendid Roman “villa” with its harbour. The latter was active up to the late Roman period and its break-waters, quays and piers are all presently below sea level. Recent archaeological excavations performed during the ’90s documented the shapes of the underwater structures and specified the period of use [19, 78, 35, 71, 56, 57]. We performed measurements on the surface of the fishery foundation which was built using large stone blocks. Its shape is rectangular and it is 12.5 m long and 5 m wide. In the middle of its eastern side, some kind of steps following the natural slope of the sea floor reach the lower layer. Nowadays, the pavement surface of the fishery is at -1.20 m (tide, wind and pressure corrected) and indicates a relative sea level change of -1.80 m. Because of the depth (which is the same as the quay behind the piers) or because of the architectural typology and building technique, we cannot exclude that this may have been a thermal area (no longer active) built along the coastline, with steps at its entrance. Additional measurements were made at one of the two piers that close the Bay of Verige. This pier’s upper surface is currently located at -1m (Fig. 5 site 6) and for this site, a sea level change of 1.60 m can be estimated. 6. Data The theory used for describing the glacio-hydro isostatic process has been previously discussed [47] and its applications to the Mediterranean region has been most recently discussed in Lambeck et al. [48, 49] and Lambeck and Purcell [50]. The input parameters into these models are the ice models from the time of the last interglacial to the present and the earth rheology parameters. These are established by calibrating the model against sea level data from tectonically stable regions and from regions that are sensitive to particular subsets of the sought parameters: data from Scandinavia to constrain the northern European and Eurasian ice models [42, 51], a re-evaluation of the North American data for improved Laurentide ice models (Lambeck et al., unpublished) and data from far-field sites to improve the ice-volume equivalent sea-level function [46]. Iterative procedures are used in which far-field data is used to establish the global changes in ice volume and mantle rheology and near-field data is used to constrain the local ice sheets and mantle rheology. The

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procedure is then iterated again, using the near-field derived ice models to improve the isostatic corrections for the far-field analysis. The Mediterranean data, being from the intermediate field, has been previously included in this analysis mainly to establish constraints on regional mantle parameters and the eustatic sea level function (loc. cit.) and on rates of tectonic vertical movements [45, 3]. In this paper we have used the most recent iteration results for the ice models [51] which includes improved ice models for the three major ice sheets of Europe, North America, Antarctica and Greenland back to the penultimate interglacial, as well as mountain glaciation models including the Alps [50]. This last addition impacts primarily on the sea-level predictions for northern Italy and Slovenia. The time-integrated ice volumes are consistent with the ice-volume equivalent sea-level function previously established [46, 44]. The Italian data discussed in Lambeck et al. [48] has not been used in arriving at the new model parameters. The adopted earth model parameters are those that have provided a consistent description of the sea-level data for the Mediterranean region. The Mediterranean data alone has so far not yet yielded solutions in which a complete separation of earth-model parameters has been possible, nor in which these parameters can be separated fully from eustatic- or ice-model unknowns but the combination used here provides a set of very effective interpolation parameters that describe well the observational data and that allow for an effective separation of tectonic and isostatic-eustatic contributions to sea level. Also, the eustatic parameters determined from the Mediterranean region are consistent with those obtained from other regions of the world [44]. The solutions indicate that three-layer rheological models largely suffice for the region: an effective elastic lithosphere with thickness ~ 65 km, an upper mantle from the base of this lithosphere to the 670 km seismic discontinuity with an effective viscosity of 3x1020 Pa s and a lower mantle with an average effective viscosity of ~ 1022 Pa s (earth model m3) (see also [48]) viscosity of 2x1020 Pa s and m-3 denoting 3x1020 Pa s. For the sites within the Gulf of Trieste (Slovenia) the predictions are also very similar for the individual sites and the observations can be combined into a single sea-level function with the Gulf. At these sites the hydro-isostatic signal is greater than e.g. it is in Sardinia [4] because of the coastal geometry and the alpine 53 glaciation signal [50] and as a consequence the predicted sea levels for recent millennia lie significantly closer to present sea level than do the Sardinia levels at comparable times. Beyond the Gulf of Trieste, geographic variability in sea level becomes more significant and observations from Brijuni lie up to 2 m lower than the first group because of the coastal geometry and alpine glaciation effects. This is further illustrated in Figures 6 in which the predicted shoreline elevations and gradients are shown for three coastal sections: along the western and inner coasts of Istria and along the along the Kornati Islands (see Figure 3 for locations). The predicted gradients for the two earth models m-2 and m-3 are similar over these distances and the major rheological dependence is shown

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through the elevations. Between the southern side of the Gulf of Trieste to the southern end of Istria, a shoreline that formed at 2000 years BP would slope from north to south at about 0.3m/100 km and one along the Kornica islands would be predicted to slope at ~ 0.2m/100 km. 7. Discussion As discussed above the sea level response to the last glacial cycle is not expected to follow a eustatic function but will vary geographically across the Mediterranean and this is seen also in the examined area: the NE Adriatic Coast (Fig. 6). Any tectonic responses will accentuate this spatial variability. Thus whether the observational evidence for sea-level change is used for establishing a reference surface for estimating quantitative rates of vertical motion, for estimating eustatic change, or for evaluating the glacio-hydro-isostatic parameters, consideration must be given to all contributions. The NE Adriatic coast is a subsiding environment although for the Istria and southern Croatia coast the elevation of the MIS 5.5 shoreline is still unknown and long-term vertical tectonic rates have not yet been established. But this is an area with both historically and instrumentally recorded seismicity [30, 15] and one of horizontal deformation as measured by space geodetic methods [72, 17]. Figure 6 illustrate the comparisons of observations and predictions for the evidence from the Gulf of Trieste and from Brijunj. At both locations the predictions lie above the observed values, irrespective of whether earth-model m-2 or m-3 is used and this is consistent with a regional subsidence. The Gulf of Trieste data points are self-consistent suggesting that the entire southern side of the gulf has subsided by the same amount, between 1.4 and 1.6 m over 2000 years, depending on the choice of earth model. Likewise, the two data points from Brijunj are selfconsistent and point to a comparable subsidence, of 1-4 to 1.7 m during the past 2000 years. The average sea-level estimates for the two localities are –1.53 ±0.08 and –1.70±0.10 for the Gulf of Trieste and Brijunj respectively and the difference, while statistically not significant, is consistent with the predicted gradient along the coast of Istria. As previously noted, tectonic subsidence along the NE Adriatic coast can be anticipated from the absence of deposits or morphological expressions of the MIS 5.5 level above present sea level. The Late Holocene data points alone do not permit a distinction to be made between coseismic displacement and uniform subsidence. The model predictions indicate that in the absence of tectonics sea level has been close to its present level, and possibly marginally higher, for a prolonged period (Fig. 6) and the absence of the present tidal notch, as noted in areas of falling relative sea level (relative uplift) [3] here indicates that the recent relative change has been one of rising sea level which lends support to the model m-3. West of the Gulf of Trieste from Venice, Tagliamento and Grado plains, earlier estimates indicate that here the subsidence rates have been greater at between 0.7 and 0.3mm/year [48]. The submerged notch, widely reported from the Gulf of Trieste as far south as Montenegro, occur at a depth of about 0.6 m in both the eastern portion Gulf

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of Trieste and along the Istria coast reaching 0.85 m at Briunji. For both earth models, there is a prolonged period when sea level is predicted to have been close or slightly above present sea level (Fig. 6) and in which notches can have been carved into the limestone coast only to be subsequently displaced by a coseismic event(s) of sufficient amplitude to displace the notch below the tidal range. Thus the notch itself is postulated to be the result of the eustatic-isostatic balance in sea level while its current position is an indication of coseimic activity having occurred after notch development and after the formation of the deeper sea-level markers at 2000 years BP. If model m-2 is appropriate then the notch formation would have started as early as 4000 years ago in the Gulf of Trieste and the absence of a notch below the 2000 year marker lends support to the model m-3 in which sea level did not reach its present level until much later years ago (Fig. 6). The absence of any trace of a modern notch suggests that the coseismic event was relatively recent and that sea level has continued to rise into recent time unless notch formation is influenced by surface water conditions (salinity, temperature, pH) in which case it would mean that these conditions have changed over the past 2000 years. It has been postulated that the displacement occurred as a 4th –6th century paroxysmic seismic event [68, 74, 5] but this cannot be validated by the present data as the historical catalogues [8] do not extend into this region. Recent measurements of limestone erosion-dissolution rates in the intertidal zone have shown that along the Northern Adriatic coast they are approximately 0.2 mm/yr compared with 0.02 mm/yr at measurement sites in the Trieste Classical Karst (Inner Karst) [26]. Preliminary measurements by one of the authors (Furlani) indicate that the limestone lowering values along the Tyrrhenian Sea coast are greater than those observed along the Northern Adriatic coast and this difference could be crucial to explain why the present day tidal notch is lacking in the Adriatic sea. The new data from the Adriatic region provide further evidence for the complexity of sea level change and contribute to the understanding of this change by making it possible to separate out the various causes. The area is one of rising sea level over and above any anthropological changes that may be occurring and the new data together with the model interpolations provide elements for evaluating flooding hazard scenarios where minor relative sea level rise can produce extensive coastline flooding, as in the NE Adriatic coastal region. The Adriatic coasts of Croatia, and Italy have been downlifted at 1.5 -1.6 metres, since roman times. The combined effect produced by the action of the Global Isostatic Adjustment and tectonics, both still active in the Adria block, which suffers from the complex geodynamic setting of the Mediterranean, can be responsible of a mean (regional subsidence plus cosismic displacements) of this area of 0.7 mm/y during the last 2000 years. In particular, the Adriatic coasts of Croatia and Italy have subsided by ~1.5–1.6m since Roman times at an average rate of ~0.75 mm/a (Fig. 7).

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8. Conclusion Our data provide new estimate of the relative sea-level change and vertical land movements in the Northeastern Adriatic Sea, based on archaeological, geomorphological data as well as geophysical data and model. In the studied area, the difference between the data and the used model can be attributed to active tectonics occurred during the last 2000 yr. Results show that during the past ~2000 yr, a relative sea-level change has occurred at up to -2.08±0.60m since 1900±100 yr BP in northern Adriatic. The observed changes include a vertical tectonic signal at a rate of ~0.75 mm/a occurring in the last two millennia, which produced a significant downward displacement of the coastline of ~1.5–1.6m. Acknowledgments We are thankful to: Carla Braitenberg and Franco Stravisi for the helpful discussion on tide gauge data, Stavros Frenopoulos for assistance during scuba field survey in the Adriatic coastal sites. This research has been partly funded by the Australian Research Council (K. Lambeck) and EU Project Interreg IIIA, Phare CBC Italia–Slovenia: F. Antonioli, R. Auriemma, D. Gaddi, A. Gaspari, S. Karinja, V. Kovacic´. References 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.

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Fig 1. Map of the Northeastern Adriatic Sea showing the location of the archaeological and geomorphological markers sites investigated in this paper.

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Fig 2. Sketch of the method used for the archaeological measurements and the concept of functionality.

Fig 3. Map of the Eastern Adriatic coast. The legend contains the locations where the submerged tidal notches were measured by the authors.

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Fig 4. A: The submerged tidal notch at -2.2 m, Duino (Trieste, Italy). The notch amplitude is larger than 1.0 m in accordance with the local tide amplitude. B: The submerged tidal notch has been surveyed at -0.8 m at Rovinj (Croatia).

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Fig 5a. Cross sections of the archaeological sites in the studied area and their relationships with the current and past sea level. 1, Stramare; 2, Punta Sottile; 3, San Bartolomeo.

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Fig 5b. Cross sections of the archaeological sites in the studied area and their relationships with the current and past sea level. 4; San Simone; 5 Salvore; 6, Briunj.

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Figure 6A. Comparison of predicted model results with observational evidence in the NE Adriatic coast.

Figure 6B. Same as figure 6A but on expanded scale.

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Figure 7. Photos of the sites described in this paper. A: Brijuni, site xa of Table 1. B: Brijuni, site xb of Table 1. C: Measuring the Sv. Simon pier, site x of Table 1 D: Measuring the Salvore pier, site xb of Table 1

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DIGITIZATION AND MULTISPECTRAL ANALYSIS OF ARTISTIC OBJECTS : EXEMPLARY CASES AND WEB DOCUMENTATION* GIUSEPPE MAINO AND SILVIA MASSARI † ENEA, 5, via Martiri di Monte Sole, 40129 Bologna, Italy, and University of Bologna, Faculty of Preservation of the Cultural Heritage, 5, via Mariani, 48100 Ravenna, Italy Results of multispectral analyses are presented, performed on paintings and ancient books, thus elucidating the execution techniques and the conservation status. Moreover, a multimedia database is described, used for documentation on and off-line of these and analogous studies.

1. Introduction A multispectral digital system, recently developed at the ENEA laboratories in Bologna and applied to the investigation of many artistic and archaeological works, is presented, ranging from infrared radiation to visible light and ultraviolet fluorescence, in order to perform suitable analyses of paintings, frescoes, illuminated codes, parchments, books and documents in historical archives, etc., preliminary to any restoration or cleaning. Relevant software for multispectral image analysis and digital restoration has been developed associated with and complementary to this hardware system and applied to a cases of main historical interest, namely the incunaboli and cinquecentine in the library of Minori Osservanti in Bologna and the XVI century books in the Library of Padri Minimi of Paola in Calabria (Italy) and paintings by Marco Zoppo, Lianori, Vasari, Lorenzetti, Gandolfi and Raphael. We also describe the implementation and validation of a multimedia database for archiving information about diagnostics, conservation and restoration of historical and artistic objects. The software architecture is based on a Content Management System (CMS) and allows the development of a dynamic website. This information system allows us to provide a update and easily searching engine for documentation of the work so far performed and for comparison among different analyses carried out, for instance, on paintings by the same author or of the same period of time.

* †

This work is supported by NEREA project, funded by Regione Emilia-Romagna, PRRIITT. e-mail: [email protected] ; [email protected].

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2. The GIANO project for cultural heritage Once completed the ENEA international project, GIANO (Innovative Graphics for National Cultural Heritage and young people’s Occupation) the necessity has risen to let public know its many results, creating a dedicate website. GIANO’s main purpose was to plan, set up and validate a software application (concerning innovative graphics, virtual reality simulations, linked databases) for keeping records and documentation about relevant historical and artistic cultural assets, using dedicate hyper-textual and multimedia methods. Three main applications have been implemented – for demonstrative purposes – whilst developing the project. All of them are characteristics of a wide range of cultural assets: • Libraries and historical archives, especially in Calabria and Sicily, mainly important for the existence of inedited documents related with Bisanzio presence in the Southern and Insular Italy; • Diagnostic imaging and restoration reports (including written and photographic reports) of historical and artistic assets; • Mediterranean wall mosaics (IV-XIV A.D.). All these results, useful for scientists and conservators, but also remarkable for interested people and tourists, must be available in a simple and effective way. At the moment only two ways are available to organise big size websites: • Collection of documents (hundreds or thousands) consultable by the public; • On-demand database related applications that use a dynamic way to show multimedia documents and data. The first solution requires complex, long and expensive maintenance; moreover, it is not suitable in a dynamic situation where information changes frequently. In fact, it could be very difficult to maintain the data consistency, while their updates should be done by dedicated people, with a relevant consequent expenditure of time and human resources. On the other hand, the second scenario matches more with the above situation. It consents to produce a large number of web-pages, re-using graphic components, maintaining distinct interface layouts and developing the code to recover web-pages data. Moreover, it allows a proficient management of all human resources involved in the project. The main aim of this project was therefore to create databases to hold and integrate all GIANO results: For this reason is important to implement applications that let users know the data sources, producing on-demand documents. 3. Multispectral non-destructive analyses An interesting example of multispectral investigation performed within the GIANO project is represented by the diagnostic analyses on the panel of St.

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Giovanni Evangelista by Pietro Lorenzetti, kept at the Museum ‘Amedeo Lia’ in La Spezia (see figure 1), and attributed to this important artist by Federico Zeri in nineteen- sixty eight.

Figure 1. The panel representing St. Giovanni Evangelista in the ‘Amedeo Lia’ museum by Pietro Lorenzetti.

3.1. History of the painting This panel, that was part of a famous split polyptych, had to be opposed, according to the traditional tipology of similar paintings, to a St. Giovanni Battista that probably was at the other side of the panel. Two parts of this panel represent St. Caterina d’Alessandria at the Metropolitan Museum in New York and St. Margherita at the Mason Perkins museum in Assisi. Moreover, other splitted parts are the two sides of the Madonna with the child coming from the Loser heritage at Palazzo Vecchio in Florence. A probable reconstruction of the polyptich sees the Madonna in the middle, the two saints at her sides (St. Margherita is on the left, and St. Caterina d’Alessandria is on the right) and at the far sides the Saints Giovanni Evangelista and Giovanni Battista, whose panel is missing. Federico Zeri noted that on the upper side of the panel of St. Caterina d’Alessandria in New York there was a notice saying “S. AGNES” and that on the St. Giovanni panel in La Spezia there was an abrasion, so we can presume that there was the same writing or something similar, reminding a second upper order. We have a few more elements to prove that there was a second order above the first one: A Saint Bishop, that is in the collection De Noailesse at Fontainebleau, and two spires with a Saint Martyr and St. Antonio Abate, both in the National Gallery in Prague.

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3.2. Results of the multispectral analysis Figure 2 shows the ENEA team at work in ‘Amedeo Lia’ museum during the experimental multispectral investigation performed with the instrumentation described in ref.1.

Figure 2. The multispectral apparatus operating in the ‘Amedeo Lia’ museum on the Lorenzetti painting.

Figure 3.The head of St. Giovanni Evangelista in visible light as result of mosaic of many partial frames.

Many images of small parts of the painting have been grabbed at different wavelength and then assembled by means of a suitable computer program to obtain multispectral images of the whole painting. Analyses by infrared radiation, ultraviolet fluorescence and visible light were made using the multispectral digital system MUSIS two thousand and seven. Figures 3 and 4 show a detail of the panel in visible and infrared radiation, respectively. It is possible to recognize in figure 3 the preliminary drawing that, compared with other works by Pietro Lorenzetti, confirms the attribution by Zeri to this artist. Moreover, under the abrasion there are marks of a writing of which we can read only the initial S.

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Figure 4.The head of St. Giovanni Evangelista in infrared reflectography as result of mosaic of many partial frames.

Finally, figure 5 shows the panel in ultraviolet fluorescence, where the repaintings made by preliminary restorations are identified by darker regions.

Figure 5.The head of St. Giovanni Evangelista in ultraviolet fluorescence as result of mosaic of many partial frames.

4. The multimedia database system In order to carry out our website we followed the standards of quality suggested by the Italian Ministry of the Cultural Activities and assets within Minerva Project. Experts in cultural and computer areas are involved with the important task of codifying common rules for spreading digitalized cultural assets all over Europe. The relevant guidelines can be found on the site www.minervaeurope.org: Its high standard level is accessible to everyone and what is more important, is available to everybody, special people included.

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Three main applications have been implemented – for demonstrative purposes – whilst developing the project. All of them are characteristics of a wide range of cultural assets: a) Libraries and historical archives, especially in Calabria and Sicily, mainly important for the existence of inedited documents related with Bisanzio presence in the Southern and Insular Italy; b) Diagnostic imaging and restoration reports (including written and photographic reports) of historical and artistic assets; c) Mediterranean wall mosaics (IV-XIV A.D.). Contents are so organized on the base of common categories (metadata), using a data system called “CMS” (that is Content Management System). This name suggests that CMS are: • Software; • Skills, knowledge and techniques necessary to build and manage this kind of software in a hyper-textual way (all documents are available on internet), with precise communication standards (priority, visibility, etc.). A Content Management System builds and updates a website, managing all phases: Setting, editing, publishing texts, images and sounds. Moreover, if it would be useful in a portal, it should classify and organize all the information to easily find, implement, modify and link them or to re-use them in a different part of the website: The bigger is the website, the more important is that the CMS is flexible and efficient. The mainly characteristics of a CMS are therefore: • User-friendly interface; • Fast possibility of inputting, modifying and finding information; • Capability to adapt to frame and graphic website need; • Safe and flexible usability; • Interface uploading via browser; • Use of graphic template for showing contents; • Manage of different customer roles and workflow; • Database for images, texts and graphs; • Find and integrate information from other sources; • Manage mailing lists and mail boxes; • Manage and order links, news, FAQ, events; • Searching usability; • Customise graphic contents. Some of more interesting characteristics of our website will be then shortly shown and discussed. The on-line system we used is called “Museo and Web”: it can be dowloaded with an open source license. We modified it adding new modules and adapting the database to our contents. The CMS has a “back-end” or administrative section, that permits the site organization and management, as well as the contents upload, change and/or cancellation; and a “front-end” the real site, that allows users to look up for contents. By this way the contents can be created, edited, translated and filed by

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many more users at the same time and independently, allowing a cooperative management of all the information. After installing the software, you have to login, in order to enter the administrative section. There are three groups of users who can enter this section: 1. The administrator who have a complete control on the section management, 2. The supervisor, who have less control; 3. The editors, who can’t publish contents but only write proofs. Now, entering the administrative section, there are some modules to manage contents: managing the site, the projects, the publications, the printing review, etc.. Each module consists of sub-modules. The site structure is the frame of our web programme, a sort of general index of contents and its management is carried out trough an index. Next to each diagram node there are some buttons that permit, when pushed, to create, modify or cancel any structure elements. Moving to the front-end in the site home page, one finds the project-logo that introduces the real site, the meta-surfing (top right side), offering functions like “search”, “map” and “multilingual choices”, as well as the main surfing repeated on every page, where the users can find acronyms of the main projects, the works, the places or monuments studied. Moreover, there is a part, in the home page, dedicated to the interactive functions on the site (the login for the access to special pages, to the newsletters registration, forum). The main events that can stimulate the visitor interest are on the left vertical bar. Inside the GIANO MENU you can look at : 1. The presentation of the project (intervention areas), objectives, collaborations, different types of works and materials) 2. Lectures: the ones organized by GIANO project or those in which it took part; it’s possible to do researches according to titles, years, places, categories. 3. GIANO publications: It is possible to perform researches according to titles, topics, descriptions. Pushing on the research result, it’s possible to visualize the complete description and download files. 4. The second term of the menu is the most important: It allows to enter the various activities, to see the results, etc.. For example, entering the research projects area, one can see a short presentation of the three macro-areas, of which the GIANO Project is composed: ! CONSERVATIO (specific databases creation); ! ZIKKARON (a Jewish term meaning memory, used for the creation of a prototype system, useful to transfer ancient texts in digital format with a graphic-textual methodology; used for historical libraries in Calabria (such as the library of Padri Minimi in Paola)and to take a census of inedited, file sourced about Bizantine influence in Southern Italy and Isles; ! TECHNE’ (innovative diagnostic technologies for a deep knowledge of the works of art).

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For example, entering TECHNE’, one can find a short list of all the activities (Lianori, Vasari, Marco Zoppo..); pushing one of them (for example the panel Crocifissione by Orazio di Jacopo) there will be access to the page containing all the details of the activities, the textual description of the researches and relative images, and it will be possible to see the complete work , thanks to the categories linked together in the database. Moreover, there is the possibility to read whatever one wants about the artist (biography, works of art, contemporary artists, etc..) and to overview the file dedicated to the Museum, owner of the work of art (in this case, at the Museum of Osservanza in Bologna, with touristic, historical information and with reference to all the works contained in our database and belonging to the museum. From the place or the monument, one has access to the itinerary where the monument is located (for example for the Museum of Osservanza in the itinerary Sacred Art) and see the other monuments studied during the project and included in the same itinerary. The site is still a work in progress but it will be possible to visit it soon at www.bologna.enea.it/giano. References 1. G.Maino, S.Bruni, S.Ferriani, A.Musumeci and D.Visparelli, Multispectral analysis of paintings and wooden sculptures, in Proceedings of II Congresso Nazionale AIAr Scienza e Beni Culturali, Patron Editore, Bologna (2002) 203.

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ACTUOPALAEONTOLOGY: A POLYFUNCTIONAL TOOL FOR ARCHAEOLOGY BRESSAN G1., FONDA G.2, KALEB S.1, MELIS R.3, MONTENEGRO M.E.4, MOURGUIART P.5, PUGLIESE N.3,4, RICCAMBONI R.3, RUSSO A.6, SODINI N.7, TROMBA G.7 1 Dipartimento di Scienze della Vita dell’Università degli Studi di Trieste, via L. Giorgieri 10, 34127 Trieste, Italia. 2 Via dei Leo 10, 34100 Trieste, Italia. 3 Dipartimento di Scienze Geologiche, Ambientali e Marine dell’Università degli Studi di Trieste, via Weiss 2, 34127 Trieste, Italia. 4 Museo Nazionale dell’Antartide, Sezione di Trieste, via Weiss 2, 34127 Trieste, Italia. 5 IRD, 213 rue La Fayette, 75480 Paris cedex 10, France. 6 Dipartimento di Paleobiologia e dell’Orto Botanico dell’Università degli studi di Modena e Reggio Emilia, via dell’Università 4, 41100 Modena, Italia. 7 Sincrotrone Trieste, S.S.14, km 163.5 34012 Basovizza, Italia. Actuopalaeontology is the logical synthesis between palaeontology and biology. The goals of actuopalaeontology are: i) to emphasize the role of the palaeontological disciplines within the archaeological research; ii) to realize a palaeontological guide for both, archaeologists and researchers from other disciplines, in other words, nonspecialists; iii) to reconstruct natural and/or anthropized scenarios: palaeoenvironments and palaeoclimates. In particular, this work plans to discuss actuopalaeontology’s role in geoarchaeological research, following the points of view of both archaeologist and actuopalaeontologist. The archaeologist has to obtain by him-self preliminary taxonomic and environmental observations to subsequently involve the right specialist. He should be able to recognize the organic remains found in archaeological excavations and boreholes through a first simple identification and, subsequently, obtain a preliminary palaeoenvironmental interpretation, using a table reporting the life-environment of the most common organisms. The actuopalaentologist has to better define the preliminary interpretations of the non-specialist evidencing the precise taxonomic aspects and the right palaeocological and palaeoclimatic results. The actuopalaeontologist has to interact with other disciplines; moreover, he should be able to perform specific analyses like microtomography, SEM and isotopic geochemistry to refine the palaeoenvironmenalt and the palaeoclimatic interpretations.

1. Introduction Actuopalaeontology is the logical synthesis between palaeontology and biology. It concerns the study of the modern organisms which present structures that will fossilize along the time, focusing the attention on some of their morphological features showing similar adaptations to a given environment. Thus,

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actuopalaeontology represents the obvious product of the taxonomic uniformitarianism (sensu DODD & STANTON, 1991). Earth sciences, including actuopalaeontology, show frequent and new applications towards the knowledge and exploitation of the cultural heritage. In particular, actuopalaeontology may represent a precious tool in the archaeological research to define the scenarios where men lived, evidencing the natural and anthropic processes that have determined and controlled their evolution. Thus, actuopalaeontology deals with fossils of organisms that are recent dwellers of environments located near human settlements (lakes, swamps, coastal settings, lagoons, etc.). This research intends to evidence the potentiality of this discipline towards a very important scientific sector interesting the cultural heritage represented by geoarchaeology. Premises of this work are: - the actuopalaeontologist should be able to recognise the fossils recorded in the archaeological excavations or boreholes: thus, he should demonstrate a good taxonomic knowledge; - the actuopalaeontologist should be able to link these fossils to well defined environments: thus, he should be a palaeoecologist focusing his attention on adaptive life-strategies of organisms; - the actuopalaeontologist should correlate fossils to well defined palaeoclimatic conditions; thus, he should be able to highlight climatic aspects, also considering the (palaeo)biogeography, geochemistry and other geological disciplines; - the actuopalaeontogist must respect the cultural goods: thus, if possible, he should perform analyses without damaging the materials.

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This work plans to discuss these premises following two points of view: a) the point of view of the non-specialist, who should be able to perform the preliminary observations and interpretations in order to subsequently involve the specialist; b) the point of view of the specialist (actuopalaeontogist), who will better define and refine the preliminary interpretations of the non-specialist. Thus, these points of view a) and b) will be discuss in each section below.

2. Taxonomic definition The taxonomic definition of the organisms found in the archaeological sites is essential to construct all the interpretations of the geoarchaeological research.

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a) Taxonomy is the first and main problem for the non-actuopalaeontologist. Actually, fossils are very frequently discovered by the non-specialists, who need to make a preliminary description of the same, at least. Today, the organisms that are potential fossils are very numerous: without counting, one must think to include in this fossil stock all the vegetal and animal species provided of hard (inner or outer) skeletal parts consisting of calcite, aragonite, silica, phosphate, etc. Thus, to become a taxonomist is the first problem. A methodology based on the shapes of the organisms and on a simple dichotomous key is proposed, in order to reach this preliminary taxonomic definition. Fig. 1 represents a method to obtain the taxonomic definition, based on the shapes. The identification-key proposes a series of consequential questions to the non-specialist who has found an “unknown” form (Fig. 2) in his sample. The reader has to follow the scheme from left to right, up to the final pictures which show the solution of identification. He has to answer the following questions: FIRST QUESTION: is the organism constituted by a skeleton consisting of one or more than one element? ANSWER: only one! SECOND QUESTION: kind of shape? ANSWER: conical! THIRD QUESTION: kind of growth? ANSWER: coiled! FOURTH QUESTION: kind of coiling? ANSWER; helicoidal! FINAL RESULT: GASTROPOD. Most organisms can be preliminarily recognised. Moreover, a series of index-cards will represent a useful actuopalaeontological guide, which shall also includes boxes to identify the significant morphological characteristics of the discovered organisms. Once reached a preliminary and precise autonomous taxonomic definition, the non-specialist has to contact the right specialist for detailed analyses. b) The omniscient palaeontologist, actuopalaeontologist or biologist does not exist, we hope! He normally is specialised in the taxonomic definition of few animal/vegetal groups of organisms. The most important tool is his experience. The specialist will be able to use a suitable scientific literature to correctly define species and assemblages of species. Thus, he may confirm or correct the preliminary taxonomic definitions given by the non-specialist. However, some specialists are also proposing simplified but complete taxonomic keys to widely divulgate their speciality. This is the case of the key of the red calcareous algae (Fig. 3) proposed by BRESSAN & BABBINI (2003).

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With the help of this key, the algologist may guide the non-specialist towards a good taxonomic definition using well defined simple features (thallus architecture). FIRST QUESTION: what is the external (macroscopic) aspect of this organism between these five chances? (see “home page” of the identification key). ANSWER: C one! Free-living thalli: cylindrical, formed by small branches, or subspherical with lumpy protuberances; (see table 8 in Fig. 3) SECOND QUESTION: what is the macroscopic and microscopic aspects of this organism between these four chances? ANSWER: A one! Cylindrical thalli, formed by free-living branchlets, simple or variously ramified; and tetrasporangial conceptacles multiporate, sunken; (see table 9 in Fig. 3.) THIRD QUESTION: what is the macroscopic (i) and microscopic (ii) and submicroscopic (iii) aspects of this organism between these two antinomic chances? ANSWER: A one! i - branches diameter: up to 1.5-2mm; ii - epithallial cells: flared; iii - cells of branches: medulla: rectangular; (15) 20-25 (30)µm long, 7-12µm in diameter; cortex: rectangular-tapered; 20-25µm long, 5-8µm in diameter. …..the morphometric data shall be compared with dispersion graph too. FINAL RESULT: Lithothamnion corallioides (see the synthesis of the characterization of this species: vegetative features, reproductive features, ecology; bathymetric and geographical distribution; photo-gallery). 3. Palaeoenvironmental interpretations Most archaeologists need to know the environmental evolution of the studied site in order to have a complete panorama of the events which took place in and around the archaeological site. The beds crossed by the excavations or boreholes are good archives of natural or man-related events. The actuopalaeontologist has to highlight these events through the analysis of the fossils: in this way, he can follow the evolution of wetlands, the changes of the shore-lines, the dramatic end of human settlements and so on. a) Once defined the examined material from the taxonomic point of view, the non-specialist may deal with a related preliminary environmental interpretation. An example is represented by a washed material coming from a hypothetical excavation (Fig. 4). Fig. 5 represents a scheme showing the typical life-environments of the main organism groups. The researcher can highlight the stripes corresponding to the identified organisms . In this

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case, he recognised gastropods, ostracods, characean algae and thecamoebians. This way the identified assemblage suggests a fresh water/slightly brackish water environment. b) Although probably correct, this environmental interpretation must be controlled by the specialist. Actually, the non-specialist does not always possess the sensitivity and the experience to define the autochthony or the allochthony of the studied specimens. The actuopalaeontologist is able to evidence the link which relies the organisms to a given environment highlighting their life-strategies (modes of life, feeding, etc.). He distinguishes the autochthonous and the displaced forms in relation to their preservation state, population composition and ontogenetic cycle. Well preserved shells might be probably autochthonous; vice versa badly preserved shells are very probably displaced. Some other organisms (for example, ostracods) show a growth by moulting, abandoning the previous and smaller carapaces; other forms (for example, mollusc bivalves and brachiopods) present a continuous growth as demonstrated by shells with concentric growth lines. In the former case, the finding in the sample of differently-sized carapaces might demonstrate that the form has accomplished its life in that environment: it has reached the adult stage abandoning its former and younger carapaces in that environment. In the latter case, it is presumable that a bivalve species is in situ if it is represented by a complete shell (right and left valves), even if disarticulated. On the contrary, the exclusive finding of right or left valves may suggest a transport due to currents. Additional palaeoenvironmental observations may derive from the analysis of the morphological features of the organisms. In this case, the taxonomic uniformitarianism is essential. Shape, ornamentation, size and thickness of outer skeletal parts (shells or carapaces) represent precise adaptations to a given environment. For example, strictly benthic ostracods present subrectangular carapace, both in frontal and dorsal view; their thickness depends on the degree of hydrodynamism of the bottom (fragile carapace=calm water; thick carapace=high energy water); the ornamentations (wings, spines) are prominent on bottoms of calm waters to avoid the burial in anoxic deposits, and absent in high energy settings to avoid mechanic breaking; the size is usually very reduced in calm waters and large in high energy bottoms; etc. Therefore, the specialist is able to correctly define the composition of the assemblages and to give an accurate environmental interpretation.

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4. How to become a palaeoclimatologist? Archaeologists sometimes need to know the climatologic evolution of a geographic area. Historic sources may be very important as well as the palaeontological data. Cold or warm episodes are usually evidenced by well defined organisms. For example, penguins recorded in Quaternary Mediterranean deposits indicate cold phases. On the contrary, hippopotamus bones of some Quaternary breccias reveal warm episodes. Pollen and spores analyses are some further essential tools to reveal these climatic variations. For example, samples containing conifer pollens may testify cold episodes; vice versa, tropical pollens may obviously attest warm climate. Effectively, this analysis is not easy for a non-specialist, since it requires a detailed taxonomic knowledge of plants and animals. However, the actuopalaeontologist has to sensitise the non-specialist since the palaeoclimatological background is very useful to better explain sea-level changes, evolution of alluvial plain and deepen the economic development of a given human settlement. For example, a small microcrustacean (ostracod) was recorded in some recent Aquileia stratigraphic units. Nowadays, this species is absent at this latitude, but it lives in north-central aqueous environments. It indicates a cold episode during the 4th-5th century A.D. Another very important tool to highlight the climatic changes is the isotope geochemistry. As demonstrated in several papers, the ratio of the isotopes of some elements in the organism shells may evidence the climatic fluctuation (O18/O16) , together with very detailed environmental data. For example, the geochemical data obtained from the ostracod valves are widely used. TURPEN & ANGELL (1971) demonstrated that the ions required for the construction of the valves are extracted from the water. CHAVE (1954) and CADOT & KAESLER (1977) have shown that the chemical composition of valve’s carbonate is in relation to the temperature of the water. BODEGART & ANDREANI (1981) have proved that this composition depends also on water chemistry. CHIVAS et al. (1983) proved that the concentrations of Mg of the carbonates of the valves depend simultaneously on the temperature and on the Mg/Ca ratio of the water, thus, the Mg/Ca ratio recorded in the ostracods valves can be used as an indicator of the variations of the palaeotemperature and the palaeosalinity of the water at the time of the deposition of the valves. They have also confirmed that the absorption of Sr++ is actually independent from temperature, but linked to the Sr/Ca ratio of the water. In consequence, the relation Sr/Ca of the valves reflects the salinity of the water. Moreover, the stock of the ∑ CO2 of the water depends on two factors: a) the exchange with the atmospheric CO2. b) the atmospheric production/consumption ratio of the organic matter in situ.

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Therefore, the concentrations of the isotopes of oxygen and carbon in the water are in relation to the atmospheric concentration of these isotopes. Consequently, the potentiality of these data is very high, since they allow us to refine the reconstruction of the ancient scenarios, as already demonstrated in the palaeoenvironmental research performed by one of us (M.E. MONTENEGRO) in several sites of archaeological interest (Titicaca region, etc.) 5. Without damaging the material… Cultural heritage, including fossils, deserves to be respected and protected. Actuopalaeontological research is usually performed with non dramatically destructive methods. However, sediment samples coming from excavations or boreholes must be treated and analysed in laboratory. Simplifying, this phase requires the elimination of the finest grain-size fraction (washing through specific sieves) and the destruction of the organic matter (hydrogen peroxide treatment). The final product is represented by the micro or macroscopic material that will be analysed by the actuopalaeontologist. New methodologies allow us to analyse the material without previous and dangerous treatment. Recently BRESSAN et al. (2007) have introduced a modern non-destructive approach using 3D X-ray microtomography before SEM analysis. The goal of this study is to easily identify the important features which are not evident without breaking the thallus of the plant. Actually, red algae are now increasingly identified within the archaeological research in Mediterranean areas. Thus, the algae may acquire progressively more importance in defining the ancient marine scenarios of archaeological interest. Since they are often encrusting organisms on manufacts (for example, necks of Roman amphoras), it is very important to avoid breakings and damages. Computed microtomography (µ-CT) satisfies this requirement: it is one of the most advanced techniques in the field of non-destructive evaluation tests. It allows imaging of the internal microstructure of the rock and soil pore space, by measuring the three-dimensional X-ray attenuation coefficient map of the sample. Thus, red algae may give environmental and climatic data that become very useful in these sites. 6. Final considerations The actuopalaeontologist has to guide the non-specialist towards preliminary interpretations. Basic tool is a right identification of the organisms, which is propaedeutic for further environmental and climatic interpretations. Therefore,

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next step shall concern the planning of an actuopalaeontological guide to mainly address the archaeologists towards these simple interpretations for geoarchaeological research. In this way, this purpose should meet the numerous archaeologists’ requirements. Providing preliminary data, this guide should address the archaeologists towards the collaboration with specialists of palaeontological and geological disciplines in general. Therefore, the reconstructions of the ancient environments, where men lived, may become more refined, also with the integration of the results of the geochemical analyses, which provide a climatic framework of the area. With this method, actuopalaeontology and in general geological disciplines might present an important role, not only for the palaeoenvironmental and palaeoclimatic interpretations, but also by the proposition of non-invasive methodologies for the better preservation and exploitation of the cultural heritage. References BODERGAT A.M. & ANDREANI A. M. (1981). Mise en évidence de la réponse adaptative d'une espèce euryhaline Cyprideis torosa (JONES, 1850) à des conditions écologiques difficiles par l'analyse multi-élémentaire en spectrometrie de masse à étincelle; International Symposium on Concept and Method in Paleontology : contributed papers, Barcelona, 5–8 May 1981 / edited by Jordi Martinell. Universidad de Barcelona, Departamento de Paleontologia, 135–140. BRESSAN G. & BABBINI L. (2003). Corallinales del Mar Mediterraneo: guida alla determinazione. Biol. Mar. Medit. 10 (2) :1–240. BRESSAN G., FAVRETTO S., KALEB S., TROMBA G. & VITA F. (2007). Applicazione della microtomografia computerizzata a raggi X allo studio predittivo della struttura di alghe rosse calcaree, XXXVIII Congresso Società Italiana di Biologia Marina, 28 maggio – 2 giugno 2007, S. Margherita Ligure (GE). BRESSAN G., FAVRETTO S., KALEB S., TROMBA G. & VITA F. (2007). X–Ray microtomography application to a predictive evaluation of coralline algae structure. Elettra Synchrotrone Research Highlights (Bioscience and soft matter): (science update series): 28–29.

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CADOT H.M. & KAESLER R.L. (1977). Magnesium content of calcite in carapaces of benthic marine Ostracoda. University of Kansas Paleontological Contributions, Paper 87, 1– 23. CHAVE K.E. (1954). Aspects of the biogeochemistry of magnesium. 1. Calcareus marine organisms; Journal of Goeology, 62: 266–283. CHIVAS A., DE DECKKER P. & SHELLEY J.M.G. (1983). Magnesium, strontium end bariumpartitioning in nonmarine ostracode shells and their use in paleoenvironmental reconstructions - A preliminary study. In: Maddocks, R. F. (ed.) Applications of ostracoda. 8th International Symposium on Ostracoda. University of Houston Geosciences, Houston: 238–249. DODD J.R. & STANTON R.J. (1990). Paleoecology, Concepts and Applications, 2nd Edition, J. Wiley Ed.: 502 pp. TURPEN J. & ANGELL R. (1971). Aspects of molting and calcification in the ostracode Heterocypris. Biological Bulletin, 140: 331–338.

Acknowledgments The authors thank DR. L. BABBINI, DR. S. FAVRETTO AND DR. F. VITA for their useful advice in preparing this work.

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FIGURES:

Fig. 1: the identification-key: a method to obtain the taxonomic definition, based on the shapes.

Fig. 2: the “unknown” form.

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Fig. 3: the key of the red calcareous algae proposed by BRESSAN & BABBINI (2003).

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Fig. 4: washed material coming from a hypothetical excavation. 1-ostracod; 2-gastropod; 3thecamoebian; 4-characean alga (girogonite).

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Fig. 5: scheme showing the typical life-environments of the main organisms groups. Red highlight indicate the organisms found in the sample and their related life-environment. This way, the deposit of the excavation (see Fig. 4) belongs to fresh water or slightly brackish water environments.

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Fig. 6a: a slice performed at the SYRMEP beamline of ELETTRA: the high resolution of this image highlights a peripherical zonation produced through a periodical calcification (see the bands).

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Fig. 6b: preliminary non-invasive microtomography slice to choose our target: this predictive method produce a lot of slices that allow us to orientate the very small micro biopsy to the subsequent not destructive ultra structural analyses at the Scanning Electron Microscope (SEM).

Fig. 7: a SEM digital photo of an epibiosis phenomenon highlighted by means a microbiopsy (see Fig. 6b - circled area). You can see easily four layers of organisms as: diatoms, serpulides, coralline algae, cyanobacteries.

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ROBOTICS TOOLS FOR UNDERWATER ARCHAEOLOGY G. CONTE, S. ZANOLI, D. SCARADOZZI, L. GAMBELLA Dipartimento di Ingegneria Informatica, Gestionale e dell’Automazione Università Politecnica delle Marche via Brecce Bianche - 60131 Ancona - Italy The use of remotely operated vehicles and of automatic data gathering and processing techniques can provide new tools and methods for the investigation of underwater archaeological sites. This paper describes part of the work done in this direction in the framework of the European research project VENUS!, focusing on the development of efficient procedures for using Remotely Operated Vehicles in exploring and mapping underwater archaeological sites.

1.

Introduction and motivation

Underwater archaeology can provide valuable information about practically all aspects of life and organization of the societies that developed maritime activities or interacted in some way with the marine environment. Unfortunately, the study of submerged archaeological sites, mainly wreckage sites, is made difficult by the harsh characteristics of the environment. In traditional marine archaeological surveys, on-site data collection is performed by divers and it implies manual recording of a large number of measures and pictures. The investigators have to return repeatedly to the same location and the whole process is expensive, demanding, cumbersome and time consuming. A possible way to overcome these difficulties consists in developing tools and methods that allow to employ Remotely Operated Vehicles (ROV), originally conceived for the off-shore industry, in the exploration of submerged archaeological sites [5, 6, 7]. ROVs can substitute divers in taking pictures and videos of underwater sites, with little or no modifications of current practices and procedures, increasing productivity and reducing, at the same time, risk and labour for human operators. Since ROV’s can reach depths which are beyond divers’ capability, can work for long periods of time in unfavourable conditions !

Work partially supported by the European Community under project VENUS (Contract IST034924) IST Programme 6th FP for RTD". The authors are solely responsible for the content of this paper. It does not represent the opinion of the European Community, and the European Community is not responsible for any use that might be made of data appearing therein.

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and can easily carry heavy and sophisticated equipment, the advantages of their use, also at this elementary level, are obvious. However, ROV’s and the related technology can be better exploited for developing and implementing new techniques and procedures, which can greatly improve the practice of underwater archaeological exploration. The work described here goes in this direction, with the aim of defining new, efficient methodologies for applying ROV’s to that field. In exploring submerged archaeological sites, the ROV can be used to carry the sensors of an automatic system which, collecting and processing data, produces on-line - that is during the acquisition phase - enriched maps of the sites. The construction of such maps represents an efficient way of structuring the data, namely the images collected by the ROV, by exploiting inherent space and time correlations, which generates valuable information. In addition, the availability of the maps during the acquisition phase allows one to guide and control the work in a logic feedback fashion, with the effect of increasing performances and accuracy. Further processing, in a second time, generates 3D representations of the site in virtual reality, that may be used for deepening the archaeological study, for documentation and monitoring of the actual condition of the site and for dissemination of the information to a large audience. In the sequel, we summarize part of the work done in the framework of the EU research project VENUS [1, 2] for defining and realizing a novel procedure that integrates hardware and software components in a practical, operational scheme for the semi-automatic exploration and survey of underwater archaeological sites. Besides avoiding the use of divers, novelty is given by the availability on-line of the survey’s outcomes and by the consequent possibility to implement a logic feedback strategy for governing the whole activity. The operational scheme realized for employing the ROV will be described in Section 2, together with the ROV’s sensory apparatus, the procedure for data acquisition and the basic lines of the data processing. The processing exploits both filtering and data fusion techniques, as well as photogrammetric techniques, that produce photographic, enriched maps by mosaicing pictures. Only the conceptual aspects of the work will be described, while, for technical details, reference is made to [1, 2,]. To conclude, Section 3 mentions the experimental activity and it describes the lines of future work. 2.

Development of an operational scheme

One of the main activities in the survey of underwater archaeological sites consists in mapping the site on the basis of manual sketches and of photos. A

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large amount of photos and videos can be collected in a semi-automatic way by using Remotely Operated Vehicles (ROV), which are guided from the surface and can carry photo/video-cameras and lighting apparatus. ROVs can also bring sonar close to the site, taking high resolution acoustic images of it. Generation of a map by patching together photos and its enrichment by the 3D information contained in the acoustic images is, to some extent, possible if the camera’s position and orientation are known for every shot and if acoustic and optical images can, in some way, be correlated. This can be viewed as a data association problem, in which auxiliary data need to be correctly associated to the principal ones, namely to photos. Photos are then patched together by specific mosaicing and photogrammetric techniques that, in particular, exploit the information generated by data association. The solution of the data association problem mentioned above, however, presents a number of difficulties, due to the nature of the involved data and to the characteristic of the acquisition methods. In order to enter into the details, it is convenient to refer to a specific experimental equipment, as the one described in the next section.

2.1.

ROV and sensory apparatus

The ROV that has been used in developing and validating the work described in this paper is a small work-class DOE Phantom S2 [4]. The sensory apparatus of the vehicle used for navigation consists of a monocular CCD PAL camcorder, an Inertial Measurent Unit (IMU), a compass and a depth meter. Additional sensors have been installed on board in order to perform the archaeological survey. These are a high definition photo-camera (Nikon D300, 14mm Sigma™ lens, 2 flashguns Nikon™ SB800), a DV video-camera (Sony HDR-HC7E) and an imaging sonar (675KHz, fan beam Kongsberg Simrad MS1000). The system comprises also an Ultra Short Base Line (USBL) acoustic positioning system, consisting of a measuring unit on the ROV’s supply vessel and a transponder on the ROV (35–55KHz Sonardyne Scout). Although different configurations are possible, the one chosen shows a good balance between efficacy, versatility and cost. The ROV’s Navigation, Guidance and Control (NGC) system is implemented on a PXI/FPGA/PC station. Its structure allows manual guidance through a console or automatic guidance, by means of a virtual reconfigurable Man/Machine interface, using data coming from the navigation sensors [4]. At low level, an onboard real-time microcontroller (Freescale 68K/Coldfire RISC MicroController) takes care of interfacing the additional optical and acoustic

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sensors (photo/video-camera and sonar) with the NGC system. The NGC system processes all the data coming from the sensors and from the USBL positioning system and it assists the operator in guiding the ROV, by implementing autodepth and auto-heading procedures that keep constant the depth and the heading of the vehicle during the survey. The sensors have very heterogeneous characteristics and they provide data with different modalities and formats, as described in the following Table. Table 1. Characteristics of sensors and data. Sensor

Characteristics of data

Acquisition frequency

Photo-camera

JPG image

0,3Hz

Video-camera

Video Stream - DV - Full HD

25fps

3axial accelerations and angular velocity, pitch

250Hz

IMU

and roll angles (attitude = roll, pitch, yaw angle) Compass

Yaw angle (Magnetic North reference)

20Hz

Depth meter

Depth

200Hz

Sonar

Acoustic return

10Hz

USBL

Geographic coordinates x,y,z (DGPS reference)

1Hz

2.2. Data acquisition Optical and acoustic images acquisition takes place while the ROV performs a sequence of parallel, linear transects above the area of interest. During each transect, the ROV’s speed and average distance from the seabed are chosen according to the shooting frequency and to the characteristics of the photo/video-cameras, in such a way that subsequent frames overlap, assuring a complete coverage of the surveyed area. The photo-camera can be operated in an automatic way by setting the shooting frequency or manually. Since natural light is scarce, the use of flash is mandatory and, due to the recharging time of the flashguns, this limits the frequency of acquisition of the photos (about 1 photo every 3s with the experimental equipment we consider). While the video stream is recorded, low quality images are obtained by sampling it at 10Hz. Heading, depth and speed are automatically kept constant by the NGC system of the ROV. Acoustic images of the sea bottom are taken automatically at the frequency indicated in Table 1, as well as navigation (accelerations, angular velocities, pitch, roll and yaw angles, depth) and position data [8, 9]. The USBL positioning system works by evaluating the coordinates of the measuring unit by Differential GPS. The transponder located on the ROV allows then to evaluate the relative position of the vehicle with respect to the measuring

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unit and, from this, the position of the vehicle in the DGPS reference is computed. The use of acoustic measurements in computing the position induces a delay of about 1s in the acquisition. The effect of measurement errors is attenuated by the use of Kalman filtering in the USBL positioning system.

2.3. Data association and processing Data association aims at enriching the information contained in each photo and, therefore, it uses the sequence of high definition images and that of sampled low quality images as main data. Basically, data association is made using the timestamp associated to every single sensory datum, coping with the differences in the acquisition frequencies. At a first level, JPEG/EXIF data are created by associating to each (low and high quality) image the last datum available from each navigation sensor, from the sonar and, taking into account the inherent delay, from the positioning system. In principle, this allows to get with reasonable accuracy and almost in real-time information about position and attitude of the photo/video-camera at every shot. The associated acoustic image, in addition, provides information about the distance between the camera and the pictured area. Actually, in this way raw measurement errors are not filtered and they may disturb any subsequent processing or use of the JPEG/EXIF data. Since navigation data are acquired at a relatively high frequency and since the delay in acquiring the position forces, in any case, to delay also the data association, navigation data (attitude, depth) can be filtered over a suitable time interval (up to 3s, for association to high quality images, or up to 1s, for association to low quality images). The position evaluated by the positioning system is not a raw data, since, as mentioned above, Kalman filtering is used in its computation, and hence the last available datum can be directly associated to each image. Similar considerations apply to acoustic images, which are obtained by filtering the returns of single pings. On-line processing, at this point, consists in mosaicing the acquired photo. This operation is performed using specific image processing techniques based on SIFT [3], which look for corresponding features in groups of images. Information about camera position, attitude and distance from the seabed contained in the EXIF area is used to guide the process of searching for corresponding features (in particular by selecting overlapping images and by orienting and scaling images) and this helps in increasing performances by reducing uncertainty and speeding up the operation.

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2.4. Operational scheme in archaeological survey The result of the on-line processing described above is a 2D map of the site that is made directly available to the scientific investigators on the ROV supply vessel. The survey and exploration of an archaeological site can therefore be organized according to the operative scheme of Figure 1, where the logic sequence of phases which characterizes the work is illustrated. Starting from preliminary information on the site, collected by various means from the surface or underwater, archaeologists determine the areas and the waypoints of the survey. The mission is designed in details by engineers and, during the acquisition, information is displayed, in form of 2D map, to archaeologists. On the basis of the outcome, they can therefore modify the waypoints and the objective of the missions during its execution in a logic feedback fashion, so to guarantee area’s coverage in spite of occasional malfunctioning of the photo/video apparatus, to correct possible errors in the previous planning and to focus on interesting features. It is clear that this way to operate improves efficiency and efficacy with respect to the traditional one, in which the survey’s outcome is available only at the end of the acquisition phase. The definition of this operational scheme and its validation represent a substantial achievement in the development of new techniques for the exploration of archaeological underwater sites and they are among the basic contribution of VENUS [12, 13]. The JPEG/EXIFF data can further be processed using photogrammetric techniques and fused with acoustic images of the sea bottom in order to generate 3D maps of the site [10, 14]. In this off-line phase, the construction of the 2D mosaic is revisited and, with the aid of sonar data, images are enriched with relief. In some cases, geo-referenced bathymetric maps of the area, constructed by means of side-scan sonar from the surface, are available. Resolution of such maps can be increased by means of the sonar data collected, at close distance, by the ROV and optical images can be represented on them. In addition, tags containing notes or links to data bases of archaeological interest can be added in order to augment the content of information [11]. 3D augmented maps can be imported into virtual reality environments, which reproduce the submarine world, and be navigated in order to simulate a tour of the site. The possibility to explore the site in virtual reality represents potentially a powerful tool for making easier its study and preservation and for making it known and accessible to a larger audience. 3.

Conclusions

The procedures described above have been developed, tested and validated by means of the experimental activity performed so far in the framework of the EU research project VENUS in several missions. Sites located at different

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depths have been explored in the Tyrrhenian Sea (near the Island of Pianosa, Tuscany Archipelagos, Italy), in the Adriatic Sea (Tremiti Islands, Italy) and in he Atlantic Ocean (mouth of Sado River, Portugal). In those missions, the ROV has acquired images, respectively, of a large, scattered group of Roman amphorae and fragments on an almost flat, sandy sea bottom and of heaps of tiles, representing the cargo of sunken vessels, on a rough, rocky sea bottom, at depths of about 30m and 60m . Data association and processing have been refined and formalized using the data collected in the missions and the experience acquired in the field operations. Sample of the maps constructed on line and by post processing are visible on the VENUS web site [1]. The operational scheme described in Section 2.4 has been implemented, tested and validated in several sea trials. In conclusion, the results obtained in the experimental activity validate the method and they represent a fundamental step in the development of semiautomatic procedures for exploiting efficiently ROV’s and marine robotic technology in the exploration of submerged archaeological sites. Progress in this direction will provide new means for archaeological studies and will eventually contribute to increase the knowledge and the preservation of important aspects of cultural heritage. In the framework of the EU research project VENUS, the work will continue to increase the performances and the level of automation in data acquisition and processing and to realize efficient procedures for reconstructing archaeological submerged sites in virtually real environments.

References 1. http://www.venus-project.eu 2. http://piccard.esil.univmed.fr/venus/deliverable.html, Public deliverables 3. D.G. Lowe, Object recognition from local scale-invariant features, Proc. ICCV 1999, Corfu, Greece (1999). 4. S. M. Zanoli and D. Scaradozzi, Automatic Control of a Low-Cost Commercial ROV, Proc. UUST 2003, Durham, NH (2003). 5. G. Conte, A. Caiti, G. Casalino and S. M. Zanoli, Underwater archaeology: available techniques and open problems in fully automated search and inspection, Proc. Workshop on Innovative Technologies for Underwater Archaeology, Prato, Italy, (2004). 6. P. Chapman et al., VENUS, Virtual ExploratioN of Underwater Site, Proc. XX CIPA /VAST 2006, Nicosia, Cyprus (2006) 7. G. Conte, A. Caiti, G. Casalino and S. M. Zanoli, Innovative technologies in underwater archaeology: field experience, open problems, research lines, Chem and Ecol., 22 (2006).

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8. G. Conte, S. M. Zanoli, D. Scaradozzi and L. Gambella, Underwater Archaeological Data Collection by means of ROVs, Proc. IFAC CAMS 2006, Ancona, Italy (2006). 9. G. Conte, S.M. Zanoli, D. Scaradozzi, L. Gambella and A. Caiti, Data Gathering in Underwater Archaeology by means of a Remotely Operated Vehicle, Proc. XXI CIPA, Athens, Greece, (2007). 10. P. Drap et al., Photogrammetry for virtual exploration of underwater archeological sites, Proc. XXI CIPA, Athens, Greece, (2007). 11. R. Jeansoulin and O. Papini, Underwater archaeological knowledge analysis and representation in the VENUS project: a preliminary draft, Proc. XXI CIPA, Athens, Greece, (2007). 12. S. M. Zanoli, G. Conte, D. Scaradozzi, L. Gambella and A. Caiti, Proc. UUST 2007, Durham, NH (2007). 13. G. Conte, S. M. Zanoli, D. Scaradozzi and L. Gambella and V. Calabrò, Underwater Archeology Missions Design for Data Gathering Automation, Proc. MED'08, Ajaccio , France (2008). 14. P. Drap et al., Underwater cartography for archaeology in the VENUS project, to appear on Geomatica.

(B)

(D)

(C)

(A)

(E) (L)

(I)

(G)

(F)

(H)

(A) Surface vessels/UUV/Divers survey ; (B) Preliminary map of the site; (C) Archaeologists ; (D) Definition of survey’s goals and waypoints ;(E) Engineers; (F) Mission preparation and design;(G) Photos/videos and navigation data acquisition by ROV; (H) JPEG/EXIF data generation: Photo [JPEG area] and Navigation Data (position, attitude, depth, distance from bottom, sonar return)[EXIF area]; (I) Data processing tools and supervisors; (L) 2D mosaicmaps (3D maps from post- processing) Figure 1. Operational scheme in survey and exploration missions on underwater archaeological sites

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ACCELERATORS AND RADIATION FOR ART AND ARCHAEOLOGY CLAUDIO TUNIZ The Abdus Salam International Centre for Theoretical Physics, Trieste, Italy Accelerators, high energy particles and radiation provide advanced scientific tools and procedures, mainly developed in physics research, which can be used for the nondestructive characterisation of cultural heritage materials.

1. Introduction New microscopes based on synchrotron radiation, neutrons, ion beams, lasers and other radiations, or particles can reveal non-destructively the structure and composition of art objects and archaeological remains. The analyses are applied to a variety of ‘hard’ materials, such as artefacts in metal, ceramics, stone or fossil human teeth and ‘soft’ materials, such as textiles, wood and paper. Each kind of material requires a different analytical strategy and the use of a suitable probe. The morphological, elemental and isotopic composition inferred from the analyses of these materials is important to art history, archaeology, anthropology and other areas of research relevant to cultural heritage. This in-depth characterisation can be used to develop appropriate strategies for the conservation of cultural heritage sites and objects. 2. Characterisation of cultural heritage materials Cultural heritage materials need to be characterised in the four dimensions of time and space, spanning scales of many orders of magnitude. Chronologies from decades to million years can be measured by ‘clocks’ based on radioactivity and other phenomena characterised by predictable changes with time. Satellite imaging and laser scans provide tools of increasing sophistication for prospecting cultural heritage sites on space dimensions from kilometres down to centimetres. Composition and structure of cultural heritage materials is analyzed down to the nanometre scale using new microscopes based on synchrotron radiations and high energy ions. The analysis of isotopic ratios for elements such as carbon, oxygen, nitrogen, calcium, strontium and other elements provides useful information to reconstruct migration patterns and diet of ancient human populations.

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Genetic science offers novel approaches to cultural heritage studies. For example, the analysis of ‘ancient DNA’ has been applied to investigations of Egyptian mummies and Neanderthal remains. In the following we will discuss more details on advanced instruments and methods used in studies of cultural heritage.

3. Dating An important objective in cultural heritage studies is to order chronologically past events by analysing materials associated with past human activities. Relative chronologies can be deduced from circumstantial evidence, such as change of style and manufacturing technique. Relative chronological information can also be obtained using methods based on time-dependent geological and chemical changes (e.g., stratigraphy, sedimentation rate, weathering, hydration and magnetism). Certain kinds of cyclic phenomena, such as tree ring or varve formation, will yield very precise chronologies if stringent precautions are followed. Finally, many methods providing absolute chronologies are based on time-dependent phenomena related to natural radioactivity, and include: 1. 2. 3. 4.

decay of long-lived radionuclides produced by cosmic rays, as in the radiocarbon method; in-situ production by cosmic rays of long-lived radionuclides, such as 10Be, 26 Al and 36Cl, which can be used for dating rock surfaces and stone artefacts; build-up of radiation exposure effects, in thermoluminescence (TL), optically stimulated luminescence (OSL), electron spin resonance (ESR) and fission track dating; build-up of a radiogenic daughter from a primordial radionuclide, in K-Ar, Ar-Ar and U-series dating. 14

C is the most widely used of these chronometers. In the late 1940s, the development of radiocarbon dating by detection of the 14C residual activity revolutionised archaeology providing a precise and direct measurement of the time scale for the development of human activities during the late Quaternary. In particular, radiocarbon dating had a strong impact on the understanding of European prehistory, previously dated only by correlation with the historical chronology of the Near East. In the late 1970s , the development of direct atom counting by AMS enhanced more than a million-fold the sensitivity of 14C analysis. Extensive AMS work followed, particularly in the analysis of radiocarbon and other cosmogenic radionuclides for archaeological, geological and environmental applications [18, 19]. Through the non-invasive analysis of famous artefacts and

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findings such as the Shroud of Turin [3] and the Ice Man [11], AMS has gained widespread public recognition as a dating technique. Also 10 Be has been used for dating in archaeology [1].

Figure 1. Comparison of the datable time span of different dating techniques [21] .

4. Accelerator microanalysis Particle accelerators were developed more than seventy years ago for basic research. There has been a major shift in the past twenty years towards their use in the analysis of materials composition and structure for interdisciplinary applications, including cultural heritage. Low-energy ion accelerators, originally constructed for nuclear physics, wereturned to other uses as the effort in their initial application faded. They have evolved into specialised tools for ion beam analysis (IBA) and accelerator mass spectrometry (AMS) [18]. An IBA facility totally devoted to cultural heritage studies has been operational for nearly 20 years at the Louvre museum [9]. A laboratory has been established in Florence with the main purpose of performing applications of nuclear techniques to solve problems related to cultural heritage (http://labec.fi.infn.it). Synchrotron accelerators have become dedicated facilities, optimised for emission of bright

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electromagnetic radiation, an ideal microanalytical probe. A large fraction of beamtime on one of the beamlines at the European Syncrotron Radiation Facility in Grenoble is dedicated to palaeoanthropology. Finally, high-energy proton accelerators are used in spallation sources for producing pulsed beams of neutron to characterise the structure of materials. The neutron tomography at the neutron spallation source of the Paul Scherrer Institute in Switzerland has been used in a several cultural heritage applications. 4.1. Ion beam analysis Please preserve the style of the headings, text font and line spacing in order to provide a uniform style for the proceedings volume. Ion beams lose energy by ionisation of the atoms composing the target material caused by the interaction of the Coulomb field of the projectile with the atomic electrons and also by nuclear scattering from the nuclei of the atoms. The range of ion beams - in materials is short, with relatively well defined end point. By comparison, x rays are attenuated according to an exponential law and sample a much greater amount of material. Ion beams are used for trace element determination using the characteristic x-rays produced in the ionization process. Ion beams can also interact directly with atomic nuclei. Nuclear reactions, including elastic and inelastic scattering or Coulomb excitation, are useful to identify specific elements and nuclides in the sample. Concentration of individual elements or isotopes as a function of depth is possible using narrow nuclear resonances and energy loss of ions as they travel in the material. Detection methods for x-rays, !-rays, charged particles and neutrons have been developed in parallel with the development of accelerators, ion sources and other instruments necessary for the production of ion beams. Combination of different ion beam analysis techniques such as PIXE (particle induced x-ray emission) and NRA (nuclear reaction analysis) can be used to determine elemental composition for elements from hydrogen to transuranic elements. PIXE is by far the most widely applied of all ion-beam related techniques used in analysis of cultural heritage materials. It is used for routine detection ofelements with atomic numbers greater than perhaps 13, using simple energy dispersive x-ray detectors. The detection limits are not constant across the periodic table, but are extremely good in many critical regions such as for the transition elements and for heavy elements such as lead and mercury. It can be used in different modes: broad beam for analysis of bulk samples and microbeam for measurement of individual features. Maps of the composition of heterogeneous samples can be obtained by rastering the beam across the sample and making a point-by-point determination of the element present. NRA is used to make sensitive determinations of many specific isotopes. In general, nuclear reactions and elastic scattering are used for detecting specific elements/isotopes throughout the periodic table. However, nuclear reaction

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analysis is particularly helpful for elements with Z<20 since the sensitivity of PIXE decreases rapidly for smaller atomic numbers. Strongly resonant nuclear reactions induced by 15N and 19F beams are used to probe the concentration of hydrogen as a function of depth. Inelastic scattering of protons (PIGE - proton induced !-ray emission) is used to detect Li, B, F, Na, Mg and Al. (d,p) reactions can determine the concentration of oxygen and carbon. Ion microbeam analysis uses an ion beam focussed to micron dimensions. Imaging can be performed using the secondary radiation induced by the primary beam, such as in PIXE and NRA, or using the energy loss of transmitted primary ions. External beam analysis is important in cultural heritage studies for the analysis of samples that, for their composition or size, cannot be inserted in vacuum chambers. In this case, the ion beam passes from the vacuum through a few-micron thick polymer window into the room atmosphere. Samples placed at the beamline exit window can be x-ray analyzed in air. This system is very practical for non-invasive and non-destructive analyses of precious artefacts. 4.2. Accelerator Mass Spectrometry AMS is the analytical technique of choice for the detection of long-lived radionuclides that cannot be practically analysed with decay counting or conventional mass spectrometry (MS). Its advantage is that the ambiguities in ion identification are practically removed, enabling the analysis of isotopic ratios as low as 10-15, a factor 106 lower than in most MS systems. Since the atoms and not the radiation resulting from their decay are directly counted, the sensitivity of AMS is unaffected by the half-life of the isotope being measured and detection limits at the level of 106 atoms are possible. Compared to the decay counting technique, the efficiency of AMS in detecting long-lived radionuclides is 105 – 109 times higher, the size of the sample required for analysis can be 103 - 106 times smaller and the measurement can be performed 100 to 1000 times faster. To highlight the difference between decay counting and atom concentration analysis, consider 1 g of modern carbon containing 6 x 1010 atoms of 14C, which can be measured by decay counting with 1% precision (104 decays detected) in 1000 minutes hours. With a high-intensity ion source, AMS can count 104 14C atoms in one minute, consuming only 100 mg of the source material.

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Figure 2. The ANTARES AMS facility as used for 14C AMS [17].

Van de Graaff tandem electrostatic accelerators are the optimum choice for a variety of AMS applications. Tandem accelerators working between 0.5 and 3 MV have been specifically designed for 14C analysis (e.g. http://www.pelletron.com/AMS.htm). Large tandem accelerators, originally developed for nuclear physics research, are also used to analyse a variety of rare radionuclides, including 41Ca and 36Cl [18]. 5. X-ray analysis The unique properties of synchrotron radiation (SR) make available a portfolio of imaging and spectro-microscopy techniques, using the light spectrum from the infra-red to multi-keV x-rays, of high interest in cultural heritage studies. It is beyond the scope of this paper to review all the available techniques. We will only discuss briefly the tools that are having a large impact in the analysis of art and archaeology, such as microtomography and x-ray fluorescence. In SR computed micro-tomography (!-CT) the sample is rotated in front of the detector, and several different projections are acquired. A 3D image is then reconstructed by back-projecting the profiles collected in this way with specific mathematical recipes. As for planar imaging, !-CT can be performed both in absorption or phase-sensitive modality (in edge detection or in holography regime), depending on the sample-to-detector distance.

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Figure 3 Analysis of a Nanderthal tooth with microtomography at ELETTRA, Trieste.

Three-dimensional imaging of specific elements can be obtained by combining microtomography with x-ray fluorescence induced by a scanning micron size beam (µXRF). The development of these methodologies is based not only on the availability of third generation x-ray facilities, but also on recent advances in computer power, both in terms of calculation speed and memory, considering that images corresponding to many gigabytes of data can be collected in few minutes of irradiation time. A vast range of portable systems for x-ray analysis is becoming commercially available thanks to progress in compact x-ray detectors and electronics, allowing fast, in-situ and non-destructive analysis of materials in art and archaeology. Novel instrumentation includes miniature x-ray sources, pocket-size multichannel analyzers and compact CZT (cadmium-zinc-telluride) detectors. Portable systems can be designed for multiple analyses, including xray fluorescence, x-ray diffraction and microtomography. They are increasingly used in museums, galleries and restoration institutions for precious and non movable objects. Leonardo’s Mona Lisa was recently studied with an x-ray portable system by a the group from the Centre de Recherche et de Restauration des Musees de France. This master work is taken out of the protecting glass box only once a year for restoration studies and the group had three hours for the experiment. The objective was to study Leonardo’s methods to create perceptions of depth and volume, using different layers of translucent paint. 6. Neutron analysis Neutrons can penetrate materials deeply, making them valuable analytical probes for non-destructive analysis of cultural heritage objects. They are produced by fission in nuclear reactors or by spallation reactions in high energy proton accelerators. New portable neutron sources are becoming available and

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make neutron-based methodologies more accessible to museum curators, restoration specialists and archaeologists. The activation induced during neutron irradiation increases the risks compared to x-rays, particularly in the analysis of certain metals such as gold and silver. Digital radiation detection systems such as neutron sensitive imaging plates and CCD camera systems are advantageous compared to film methods: exposure time can be much shorter and imaging algorithms can be used for imaging improvements. Neutrons have higher penetration than x-rays for many materials relevant to cultural heritage, such as metals. The most widespread imaging methods are neutron radiography (NR) and computed tomography. The group at the Paul Scherrer Institute, in collaboration with Swiss museums, is involved in the neutron analysis of 150 bronze Roman sculptures. The high lead content of these objects make neutron the only probe to study internal structures [6]A program of NR analyses has been carried out by the National Museum of Slovenia using the Ljubljana TRIGA Mark II research reactor. The scope of these analyses is for conservation purposes and to study the manufacturing technology [12]. 7. Some case studies 7.1. Works of art The analysis of paintings at the micro- and nano-metre scale using a combination of methodologies such as transmission electron microscopy, atomic force microscopy, ion beam analysis and synchrotron radiation spectroscopy th showed the innovative methodologies developed by Dutch artists in the 17 century in their representations of Nature [9]. In another study, SR has been used for K-edge imaging of paintings. In this method, two images are taken at two different energies, above and below the threshold (K-edge) energy of the element of interest. The subtraction of the two images provides the elemental map. The hidden brush strokes of the great French painter Eduard Manet were revealed using this method to image barium, lead and mercury, ingredients of a pigment lengthener used by painters during the 19th and 20th century. Scientist could re-construct Manet’s techniques to reach the final effect [4]. PIXE and SR-XRF have been used to study the drawing book of Albrecht Duerer, created by the German painter in 1521. Trace elements detected with PIXE provide information on the genesis of his creation, including the origin of the materials used and the chronology of his creations. For example, all drawings show the same chemical composition, related to the special silver point

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used (90% silver, 10% copper and traces of zinc), but one of the drawings, the ‘portrait of a young man with a fur hat’ was made with another point (83% silver, 12% copper, 5% zinc) [9].

Figure 4. ‘Tassel’ Bradshaw figures from the Kimberley, Australia. A mud-wasp nest can be seen on the rock face just above the left hand figure. Photo: courtesy of Graham Walsh, Takarakka Rock Art Research Centre [20].

The Bradshaws are Australian Aboriginal rock paintings with a unique style characterised by elegant and graceful figures with many ornaments and accoutrements. An example is shown in figure 3. Paintings of this style are found in the Kimberley region in the north west of the state of Western Australia. The paint colour is usually a light mauve or mulberry. These figures were first reported by early explorer Joseph Bradshaw who, accompanied by his brother, surveyed this region in 1891. The paintings are so unusual and distinctive that there has been much speculation and debate concerning their origins and meanings. Some researchers have gone as far as to suggest origins other than the ancestors of modern indigenous Australians. Recent fieldwork in the region started in 1994 with the aim of providing absolute dates for the Kimberley rock art sequence. Small samples of pigments, beeswax, and associated mineral crusts have been collected and are being dated by AMS, providing the first age estimates for the well-known Bradshaw painting style. The pollen contained in mudwasp nests, which overlie or underlie Kimberley rock paintings, can be dated by AMS, providing minimum or maximum ages for rock paintings [13]. Two measurement techniques were involved in this investigation – radiocarbon AMS and OSL, finding a minimum age of 17,000 BP. So the origins of the Bradshaw paintings are still unknown and further measurements to establish their ages will be required.

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7.2. Controversial archaeology 7.2.1 The Venafro chessmen The Venafro chessmen, discovered in 1932 in the southern Italian necropolis of Venafro, are among the most controversial chess-related archaeological finds of this century. For more than 60 years, archaeologists have formulated a variety of hypotheses to explain how bone chess pieces of Arabic shape were discovered in a tomb of Roman age. Some scholars claimed that the chessmen were indeed of Roman origin. The chess pieces are preserved in the Archaeological museum of Naples, where a bone fragment of 2 grams was collected for AMS analysis. AMS radiocarbon measurements yielded a calibrated age of 885-1017 AD (68 % confidence level) [16], supporting the view that this game was introduced to Central Italy during the Saracen invasions of the 10th century AD.

Fig. The Venafro chessmen

7.2.2 The Iron Crown The Iron Crown (see figure 4) of the first Holy Roman Emperor, Charlemagne, is held in the Cathedral at Monza, near Milan in Italy. The origin and age of the

Figure 5. The Crown of Charlemagne

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crown, later used to crown Napoleon Bonaparte, are uncertain. Historical records place its origin between the Roman and Middle Ages, a spread of several centuries. In 1996, it was discovered that the precious stones were held in place by a mixture of clay and beeswax, which provided enough carbon for AMS radiocarbon dating. The analysis performed at ANTARES in Sydney yielded ages of 520(30) and 760(30) AD for different components of the crown [10]. The results require a revision of the history on the origins of the Iron Crown. 7.2.3 Donatello’s glue The Annunciazione Cavalcanti (Cathedral of Santa Croce, Florence) is one of the best known creations of the Italian sculptor Donatello (1386-1466 AD). The sculpture is decorated with a group of terra-cotta cherubs. The base of one of these figures has large cracks that had been subsequently repaired with a resin glue. It is not known when the accident occurred. Our date for the glue, 13311429 AD (68 % confidence level), proved that the restoration had been performed during the lifetime of the artist. The breakage and repair may therefore have happened when the work of art was created. Italian scholars believe that the cherub cracked because it was not hollowed out before firing and that the repair was carried out by Donatello himself, after damaging the statue in the kiln.

Figure 6. Terra-cotta cherub from the Annunciazione Cavalcanti (Santa Croce, Florence)

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7.2.4 The conquest of Peru The manuscripts “Historia et Rudimenta Linguae Piruanorum” and “Exsul Immeritus Blas Valera populo suo”, which were found in the family papers of Neapolitan historian Clara Miccinelli, are commonly known as the “Miccinelli documents”. They discuss events and people associated with the Spanish conquest of Peru. In addition to details about reading literary quipus - Inca documents which were written using a combination of textile ideograms and knots - “Historia et Rudimenta Linguae Piruanorum” (History and Rudiments of the Language of the Peruvians; [5]) includes the incredible claims that Pizarro conquered the region after having Inca generals poisoned with arsenic-tainted wine and condemned the Inca emperor, Atahuallpa, to death instead of granting him anaudience with the King of Spain. The account departs markedly from the long held version of the event – that Atahuallpa was put to death for ordering the execution of his brother and rival. a letter from Francisco de Chavesa conquistador and chronicler on Pizarro’s expedition: The letter, dated August 5, 1533, was addressed to Charles V, King of Spain, and is the source of the” accusations already suggested in “Historia et Rudimenta Linguae Piruanorum and “Exsul Immeritus Blas Valera populo suo”. The historical significance of the discovered material is immense and historians considered it to be of primary importance to verify the authenticity. As a part of a worldwide research collaboration we performed the radiocarbon dating of five samples associated with the Miccinelli documents [22[ The results showed that, with a high degree of confidence, the wax used to seal the letter to the King of Spain originated earlier than 1533, the date on the letter. Similarly, the wax used for the box containing the agreement allowing Valera to write “Nueva Corónica y Buen Gobierno” under a false name, most probably originated before 1618, the accepted completion date of this important document.

Fig. 7. The calibration of the wax sample from the seal of the letter to the King of Spain.

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7.3. Prehistory and human evolution Prehistoric studies require reliable dates to answer questions related to the dispersion of H. sapiens during the late Pleistocene. DNA analysis in extant human populations suggests that modern humans left Africa 60-70 ka ago, reaching Australia around 50 ka BP, Europe 40 ka BP and America 13 ka BP. Archaeological sites with human presence need to be dated in the relevant areas to confirm these predictions. A precise chronology is also required to evaluate the impact of modern humans on the ecosystem they were invading, including their possible role in the extinction of the ice-age megafauna and of ‘less evolved’ human species they were encroaching, such as H. nanderthalensis in Eurasia and H. erectus or H. floresiensis in South-East Asia. Archaeologists and geochronologists are re-evaluating Australian archaeological sites to find out the period of overlap of people and megafauna in an effort to discriminate between human and climatic causes of extinction. The resulting dates point to a human–megafauna overlap of about 3,500 years, a number suggesting human agency and ruling out major global climate change. AMS radiocarbon dates for the dispersal of modern humans across Europe suggest an overlap with the Neanderthals of less than 5,000 years. Calibrations of the older dates are still controversial and have been challenged by some members of the dating community. The main uncertainties limiting radiocarbon dating in the range beyond 40 ka derive from sensitivity of the small concentration of residual 14C atoms (less than 1% of the initial concentration) to contamination by more recent carbon that may be introduced during burial, sample collection and laboratory chemistry processing (pre-treatment, combustion or hydrolysis and graphitisation). Using chemistry lines designed for low-level samples the Australian National University group was able to achieve a background equivalent to about 63 ka. Other substantial advances occurred in the dating of bones, particularly the ultra-filtration methods where collagen fractions with high molecular weight are separated from the lighter fractions. Some laboratories are constructing low-background vacuum extraction and graphitization systems dedicated to prepare only samples in the range 40-60 ka, designing protocols aimed at minimizing contamination of atmospheric carbon . As we mentioned before, another limitation for radiocarbon analysis in the 50 ka range is the absence of a consensus curve for calibration beyond 26 ka. A reasonable preliminary calibration curve is CalPal07, developed recently by the University of Cologne using a new Greenland time scale based on U/Th ages. There is some hope that in the future older trees, such as Huon pines from Tasmania and Kauri logs from New Zealand, will allow the extension of the tree ring record up to 50 ka and beyond.

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Palaeoanthropologists have recently discovered the power of synchrotron radiation analysis. The use of x-ray microtomography to determine nondestructively the internal structure of skulls, teeth and other fossil remains is revolutionising the field of palaeoanthropology and opening the possibility of studies that were not possible until recently. CT analyses are increasingly used to provide less subjective data related to the anatomical characters of human remains. The image contrast can be dramatically improved using new imaging methodologies including phase contrast radiography, microtomography and holotomography. The intense monochromatic beams from third generation SR facilities allow fast data acquisition with micron resolution and avoiding beam hardening effects [14,8]. Human teeth are one of the best preserved types of evidence available for human evolution studies. They provide crucial information on development, diet and health. The use of synchrotron radiation CT was applied to the teeth of S. tchadensis to demonstrate his morphological affinities with the human clade [2]. SR microtomography has provided information on internal tooth microstructure for Homo nenderthalensis. Results show that the timing of molar crown and root completion in Neanderthal is similar to that of modern humans, but they have more complex enamel-dentine junction morphology [7]. An advanced programme of nondestructive imaging of hominoid dental microstructure using phase contrast X-ray synchrotron microtomography is being promoted at ESRF. Periodic features in enamel formation such as Retzius lines and cross striations are analysed with submicron resolution to deduce variation among different human species and age of death [15] 8. Conclusions Scientists apply tools and methods of increasing sophistication in studies of cultural heritage. Here we focussed our discussion mainly on accelerator-based methods that have been originally developed for basic science. We should not disregard the intangible aspects of human culture that fall under the scrutiny of art historians, philosophers, ethnographers, archaeologists and other scholars in the humanities. Scholars from these different sectors of human knowledge should work together, with the caveat that many of the models proposed by the humanities scholars are difficult to verify with the scientific method.

References 1. Boaretto E., Berkovits D., Hass M., Hui S.K., Kaufman A., Paul M. and Weiner S. (2000) Dating of prehistoric cave sediments and flints using 10Be

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and 26Al in quartz from Tabun Cave (Israel): Progress report, Nucl. Instr. and Meth. B172, 767-771. 2. Brunet, M., Guy F. et al (2005) New material of the earliest hominid from the Upper Miocene of Chad, Nature, 434, 752-755. 3. Damon P.E., Donahue D.J., Gore B.H., Hatheway A.L., Jull A.J.T., Linick T.W., Sercel P.J., Toolin L.J., Bronk C.R., Hall E.T., Hedges R.E.M., Housley R., Law I.A., Perry C., Bonani G., Trumbore S., Wölfli W., Ambers J.C., Bowman S.G.E., Leese M.N. and Tite M.S. (1989) Radiocarbon dating of the Shroud of Turin, Nature 337, 611-615. 4. Krug, K., Dik, J. et al. (2006) Visualization of pigment distributions in paintings using synchrotron K-edge imaging, Applied Physics A83, 247251. 5. Laurencich Minelli L., Miccinelli C. and Animato C. (1995) Il documento seicentesco “Historia et Rudimenta Linguae Piruanorum”, Studi e Materiali di Storia delle Religioni 61, 363-413. 6. Lehmann, E.H., Vontobol, P., Deschler-Erb, E. and Roares, M.(2005) Noninvasive studies from culturalheritage, Nuclear Instruments and Methods in Physics Research, A 542, 68-75. 7. Macchiarelli, R., Bondioli, L., Debénath, A., Mazurier, A., Tournepiche, JF., Birch, W. and Dean, M.C. (2006) How Neanderthal molar teeth grew, Nature 444, 748-751 8. Mazurier, A., Volpato, V., Maccharelli, R. (2006) Improved noninvasive microstructural analysis of fossil tissues by means of SR-microtomography, Appl. Phys. A 83, 229-233. 9. Menu, M. (1990) IBA in the museum: Why AGLAE, Nuclear Instruments and Methods in Physics Research 45 , 597-603. 10. Milazzo M., Cicardi C., Mannoni T. and Tuniz C. (1997) Non destructive measurements for characterisation of materials and datation of Corona Ferrea of Monza, in: Handbook of The Sixth Australian Archaeometry Conference, 10-13 Februrary 1997, Sydney, Australia, p. 39. 11. Prinoth-Fornwagner R. and Niklaus Th.R. (1994) The man in the ice: results from radiocarbon dating, Nuclear Instruments and Methods in Physics Research B 92, 282-290.

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12. Rant, J., Milic, Z.,, Istenic, J, Knific, T., Lengar, I and Rant, A. (2006) Neutron radiography examination of objects belonging to the cultural heritage, Applied Radiation and Isotopes 64, 7-12. 13. Roberts, R.G., Walsh, G., Murray, A., Olley, J., Jones, R., Morwood, M., Tuniz, C., Lawson, E., MacPhall, M., Bowery, D., and Naumann, I. (1997) Luminescence dating of rock art and past environments using mud-wasp nests in Northern Australia, Nature, 387, 696. 14. Tafforeu, P., Boistel, R. et al. (2006) Applications of X-ray synchrotropn microtomography for non-destructive 3D studies o palaeontological samples, Appl. Phys. A 83, 195-202. 15. Tafforeau, P. and Smith, T., (2008), Nondestructive imaging of hominoid dental microstructure using phase contrast X-ray synchrotron microtomography, Journal of Human Evolution 54 (2008) 272-278 16. Terrasi F., Campajola L., Petrazzuolo F., Brondi A., Cipriano A., D’Onofrio M., Hua Q., Roca V., Romano M., Romoli M., Tuniz C. and Lawson E. (1994) L’Italia Scacchistica 1064, 48-60. 17. Tuniz, C., Fink F., Hotchkis, M.A.C., Jacobsen, G.E., Lawson, E.M., Smith, A.M. and Hua, Q. (1997) Research and measurement program at the ANTARES AMS facility, Nucl. Instruments and Meth. In Phys. Res., 123, 73-78. 18. Tuniz, C., Bird, J.R., Fink D., and Herzog G. (1998) Accelerator Mass Spectrometry: ultrasensitive analysis for global science, CRC Press, LLC (300 pages). 19. Tuniz, C.; Norton, G. (2008) Accelerator mass spectrometry: New trends and applications, Nucl. Instruments and Meth. in Phys. Res. . B 266, 18371845. 20. Tuniz, C. , Zoppi, U., and Barbetti, M. (2000) AMS dating in archaeology, history and art, in Radiation in Art and Archaeometry, Ed. D.C. Creagh, D.A. Bradley, Elsevier, 444-471. 21. Tuniz, C., Zoppi, U. and Barbetti, M. (2004) Radionuclide dating in archaeology by Accelerator Mass Spectrometry, Proceedings of the international school of physics 'Enrico Fermi' Course CLIV, M. Martini, M. Milazzo and M. Piacentini (Eds.), IOS Press, Amsterdam, 385-405. 22. Zoppi U., Hua Q., Jacobsen G., Sarkissian G., Lawson E.M., Tuniz C. and Laurencich Minelli L. (2000) AMS and controversies in history: The Spanish conquest of Peru, Nucl. Instr. and Meth. B172, 756-760.

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THE 14C CONTRIBUTION TO THE PROTOHISTORY OF FRIULI (NORTH-EASTERN ITALY) PAOLA CÀSSOLA GUIDA Dipartimento di Storia e Tutela dei Beni Culturali, Università di Udine (Italy) In recent years many new scientific advances have stimulated research in, and improved our knowledge of, the proto-historical domain of North-Eastern Italy, a territory that had always been a link between different geographic and cultural environments. Among the more important achievements are the new chronological data. This paper, focusing on protohistorical Friuli, employs some Radiocarbon dates recently obtained from different contexts in North-Eastern Italy so as to throw light on certain fundamental, long-debated subjects such as the chronology and duration of burial tumuli, the epoch that saw the foundation of the first “long-lasting” fortified settlements (namely the socalled “castellieri”), the chronological and conceptual relations between castellieri and tumuli, and the position of these two series of monumental structures within the European perspective.

First of all I must apologize for the fact that my paper will not be dealing with specific archaeometric themes: it simply sets out from certain archaeometric data (various recent radiocarbon tests) and aims at clarifying a number of problems that have long been debated by archaeologists, in particular those working in Friuli. Thanks to the fact that modern farming has not been too destructive everywhere, part of this region ! namely the Upper Plain, to the north of the spring-line, where water sinks through the gravel ! is still relatively rich in burial tumuli and fortified settlements (“castellieri”). These two types of structure, both very common in European proto-history, seem in Friuli not to have been constructed and used contemporaneously, and their chronology has long been uncertain (as indicated by the frequent changes of opinion on the subject in the course of the researches. The outlines of the Bronze Age cultural framework of Friuli ! in particular what is now the province of Udine, the focus of my attempt at reconstruction ! are today almost definite, with the result that this region’s role between Italy and the Mediterranean on the one hand, and the Alps and the Transalpine area on the other, is finally being recognised. The Friulian territory, as is well-known, is extremely varied, provided with many frontiers and characterized by a permanent ethnic and linguistic

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multiplicity. Cultural patterns in the different areas changed repeatedly, depending on the prevailing influences. The neighbouring cultures frequently exercised a powerful hegemony over the local groups, whose features accordingly reflect this phenomenon. One possible key to the reading of Friulian history is precisely this prevalence of influences from one side or another. We may definitely affirm that this region never played a decisive role, yet it acted as an important link between different geographic and cultural environments, since on the one hand the Alpine valleys connect it with Central Europe and, on the other, it is closely linked eastwards with the Gorizian and Triestine karstic plateau (and thereby with Istria and the Balkans), and westwards with the Veneto and the Po Plain (and from there with the Italian Peninsula). As for the two shores on either side of the Adriatic, the contacts varied in intensity.1 In recent years, both in Friuli and the neighbouring regions, many new scientific advances have stimulated research and enabled significant progress to be made. Among the most important achievements we must obviously count the new chronological data. We can but hint, given that this is clearly a subject beyond the scope of a mere archaeologist, at the profound modifications the traditional chronology of the Bronze Age has undergone as a consequence of the “revolution” caused by the calibration of 14C on the basis of the dendrochronological data, on both the southern and the northern side of the Alps2. Exploiting the new data in the interests of historical reconstruction could be a far more profitable task, all the more so as the new radiocarbon dates match the suggestions of the pottery typology. As regards Friuli, and in particular the intensively explored Udine Upper Plain, attention has focused in recent years on the significance of the distribution and chronology of burial tumuli, as welle as other problems connected with these proto-historical, artificial mounds. The excavations by the University of Udine in some of the many tumuli still dotted around the Upper Plain (fig. 1) have been providing important information not only about their earth-and-pebble building technique and their stone-core structures ! such as a cairn, or a pebble platform covering an individual coffin or a small funerary chamber ! but also their cultural framework (especially their connection with the innumerable tumuli of the Eastern Adriatic coast) and, obviously, their chronology. The starting-point was the investigation of a round barrow with an intact individual tomb (figs. 2-3), located at Sant’Osvaldo near Udine (2000–2002), 1

For a general survey on Friulian proto-history see CÀSSOLA GUIDA 2006. The consequences of the new 14C dates in northern Italy are outlined in DE MARINIS 1999. As for Europe, see e.g. FORENBAHER 1993. 2

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for which a 14C test on a bone sample pointed to the span 1970–1880 BC (calibrated 1": fig. 4).3 This chronology within the Early Bronze Age is consistent with the little information we already possessed on the subject.4 Numerous other achievements concern long-lasting settlements, namely villages fortified with earth-and-pebble ramparts, which have left a good number of easily visible remains in the Upper Plain landscape. Some of the main themes of research are the techniques and materials employed for defences, building devices, house planning, phases of use and chronology both relative and absolute. The latest excavations carried out in various fortresses, whether on small hills, such as Variano near Basiliano, or in the low land, namely Galleriano, Savalons and Sedegliano,5 have yielded a large quantity of finds ! especially pottery ! whose typology has helped to construct a more accurate chronological frame, dating the more ancient lay-outs of the villages to not later than the advanced Middle or the first Late Bronze Age (c. 1500-1300 BC). In the case of Sedegliano, fresh radiocarbon indications now point to a much higher date. Of all the results of the intense research carried out by Udine University in these opening years of C21st, some of the most important have come from the excavations in this site. The proto-historical settlement was provided with earth-work defences and ditches, in a quadrangular lay-out whose repeated reinforcement makes it the most spectacular of the three “castellieri” located in the low land, west of Udine (fig. 5). Here, inserted into the earlier earth-work, a cluster of five inhumation tombs was found (figs. 6-7). This was the first discovery of its kind in a Friulian castelliere ! prior to this we had not known of any tomb connected with a Bronze Age settlement ! which makes it an absolute novelty not only for its prominent position inside the rampart but also for the burials themselves, their rituals and their possible significance.6 The bodies ! sans grave-goods, as seems to have been normal practice in tumuli ! were laid close to an entrance. They evidently belonged to a select group of people, recognized as founders and, after their death, protectors of both the settlement and its access. These peculiarities, together with the still simple structure of the ramparts, permit us to compare these burials with those of the tumuli, and to ascribe to them similar symbolic significance and requisites, such 3

The date was obtained from the collagen extracted from a phalanx. For preliminary information on the monument and its chronology, see CÀSSOLA G UIDA, C ORAZZA 2003; CANCI, CÀSSOLA G UIDA, CORAZZA 2005. 4 For the state of knowledge on Friulian tumuli and their chronology see BORGNA, CÀSSOLA GUIDA 2007, 192-194. The most recent research suggests the possibility that they were erected by degrees, between the 3rd and the early 2nd millennium, and that at least in some cases they might have incorporated elements of the beginning of the Early Bronze Age, if not of the Late Copper Age (BORGNA forthcoming; CÀSSOLA GUIDA forthcoming). 5 Càssola Guida, Corazza 2005, 222-234. 6 Càssola Guida, Corazza 2006; Eaed. forthcoming; Càssola Guida forthcoming.

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as visibility from afar, common ancestry, show of power, asserting of possession of land or pastures. To these must be added the chronological factor, which seems to confirm our assumptions. Some radiocarbon analyses of bone samples from the buried bodies have pointed to a chronology from the advanced Early to the beginning of the Middle Bronze Age, so much higher than the one traditionally accepted for the earlier villages and not far off that of the tumuli. Of the three samples analysed, the oldest (from tomb 3, deeply inserted inside the core of the rampart) dates from 1910 to 1770 cal BC, 1" range; the two younger ! from tombs 1 and 4, closer to the outer edge of the rampart ! date respectively from 1750 to 1680 cal BC, 1" range (fig. 8), and from 1680 to 1540 cal BC, 1" range. The results, in short, indicate a time span from the C19th BC (for the older burial, and thus for the setting up of the earlier defences) to the C17th –16th BC for the more recent interments.7 If we now consider the bordering regions, namely Istria, Venezia Giulia and Trentino-Alto Adige, the most copious and interesting information concerns once again the beginning of the long-lasting settlement. The hypothesis of an earlier date instead of that traditionally pointed to (the advanced Middle Bronze Age if not the start of the Late, i.e. circa 15th–14th BC) is currently supported by the results of the researches carried out at Moncodogno/Monkodonja by a team of Slovenian, Croatian and German archaeologists.8 This fort with its imposing stone walls, complex lay-out and huge building on the hill-top (“acropolis”), rises in the immediate hinterland of Rovigno/Rovinj, on the western Istrian coast. It must have been well-visible from the sea, and so was possibly employed by sailors as an important point-de-repère from the time of its foundation,9 which has been dated to an advanced phase of the Early Bronze Age thanks to a number of 14C tests10 and to the finding of a remarkable series of artefacts both local and from further afield, namely the Balkans (a piece of probably Cetina pottery found under the acropolis walls) and Central Europe (some so-called “enigmatic objects” and a peculiar bronze pin).11 An absolute dating from the “castelliere di Slivia” in the immediate karstic hinterland of Trieste, whose earlier pottery is quite similar to that of Monkodonja, confirms that both the hill-forts were built towards the end of the Early Bronze Age, i.e. circa 1800–1700 BC. Slivia was explored more than 30 years ago by Giorgio Stacul: the radiocarbon date 1440±50 BC then obtained for 7

A. Canci, in Càssola Guida, Corazza 2006, 307. Mihovili#, Hänsel, Ter$an 2005 (with refs). 9 This idea, formulated by Elisabetta Borgna, was inserted in a paper presented in 2007 at the meeting of the EAA at Zadar (BORGNA, CÀSSOLA GUIDA forthcoming). 10 Hänsel, Mihovili#, Ter$an 2007. 11 Mihovili#, Hänsel, Ter$an 2005, 403-406. 8

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the lowest layer excited heated arguments among scholars at the time, as some were not disposed to accept such a high chronology for the beginning of the karstic castellieri.12 Now the same test, calibrated, points to a much earlier foundation (BC 1871–1666, 1" range; 1890–1606, 2" range), both for Slivia and for other fortresses,13 containing, at their lowest levels, sherds with the same characteristics. Till now, such pottery had traditionally been dated to the advanced Middle Bronze Age. Alongside Monkodonja and Slivia, we may quote the cases of Montorcino/Vr%in near Dignano/Vodnjan (inland south of Monkodonja), explored in the 1930’s by Battaglia and Tamaro, and of Elleri, near Trieste, a major site repeatedly explored since the 1940ies on a hill divided by the border between Italy and Slovenian Istria.14 The higher chronology of a certain number of stone-walled Istrian fortresses, proposed 25 years ago by Borivoj &ovi# and more recently (1994 and 1997) sustained, on the basis of new evidence, by Kristina Mihovili#, now receives important ratification.15 The same chronological frame has been applied to a mountain fortress such as Sot#iastel, in Val Badia (Alto Adige), where a 14C test on a wood coal sample provided the calibrated date of 1670±80 BC, i.e. around the transition from Early to Middle Bronze Age.16 It is worth remembering that, as in Monkodonja, so also here some “enigmatic objects” have been dug up.17 I am perfectly aware of the fact that our data are scant indeed and that, as regards 14C in particular, many more analyses would be necessary in order to reach a higher degree of certainty. However, our sempiternal problem ! scarcity of financial resources ! obliges us to proceed slowly and to make the most of our provisional results even though they are not completely satisfactory. Thus, it was partly on this somewhat shaky foundation, but much more on the archaeological data and on 30 years of fieldwork in Friuli, that I based the following highly synthesized outline, which goes from the mid-phase of the Early Bronze Age, namely the first centuries of the 2nd millennium BC, to the

12

Stacul 1972, 161. For the debate on the chronology of the castellieri: Stacul 1982, 28-29; Radmilli 1988, 160. 13 For the calibrated Slivia date, see Mihovili#, Hänsel, Ter$an 2005, 401-402. A similar chronology might be assigned to the castelliere of Nivize near Trieste and possibly to other karstic hill-forts, such as Castellazzo di Doberdò near Gorizia (Montagnari 1996, 64, with refs) and Ponte S. Quirino in the Natisone Valley (Borgna, Càssola Guida forthcoming, with refs). 14 Vr%in: Bur'i#-Matija'i# 1989; Mihovili#, Hänsel, Ter$an 2005, 402 (with refs). Elleri: Museo di Muggia 1997; Maselli Scotti et al. 1998. 15 &ovi# 1983, 127; Mihovili# 1994, 108-110; Ead. 1997, 43, 46. 16 Tecchiati 1998, 375. 17 Tecchiati 1998, 192-197, figg. 29a-32b.

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beginning of the Middle (roughly 2000–1600 BC). I am proposing it as a conclusion to and a comment upon the ideas illustrated above. At first, not only in Friuli but in a large part of the North-East, small groups of a few score individuals, bound by ties of kinship, settled in villages that were not yet completely stable, and whose temporariness makes it difficult now to locate them archaeologically. According to a type of social and economic organization that went back to the Copper Age, they seem to have been largely devoted to ovicaprid breeding; however, where it was possible, they developed an increasingly extended farming activity. They used to honour their dead chiefs by erecting what were at times very imposing funerary tumuli, whose building rules and rituals, today increasingly better known, may be compared to those of similar monuments on the Dalmatian coast.18 On the basis of the evidence gathered in recent years, it is possible to affirm that in quite a short time (starting from circa 1900–1800 BC), settlement began to become stable in the North-Adriatic territories. More groups joined together and formed larger communities, each of some hundreds of people, whose social and economic organization was territorial and tribal-based. Far more substantial villages started developing, often provided with some kind of defence from the outset. The new settlements, at first scattered about the territory, were set up in dominant positions both inland and on the coasts (fig. 9). Thus the presence of imposing forts near the sea, such as Elleri or Monkodonja, would help seafarers to find their bearings in inshore navigation and offer good shelter to ships in the landing-places beneath.19 Location strategies could depend on various requirements, such as the presence of good trade routes, the vicinity of resources such as rich pastures, arable land, or a shore suitable for salt production (as was, again, the case of Elleri, whose prosperity might in large measure be ascribed to the salt trade20). Regarding the Friulian Upper Plain in particular, which was certainly connected to the coast by easy land and river routes, our only source of information for this period at present is, as we have observed, Sedegliano. However, research being in progress, we may not exclude the possibility that the origin of other “castellieri” in key-positions may have to be back-dated.

18

Borgna, Càssola Guida 2007; Borgna, Càssola Guida forthcoming. For the importance of sea-faring and “connectivity” in the Adriatic Sea vide Borgna, Càssola Guida forthcoming (in that paper the ideas expressed on this subject are largely due to the first of the two authoresses). 20 Càssola Guida, Montagnari Kokelj 2006, 328-329. 19

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Thanks to the fresh evidence of Sedegliano we are now well-informed about the earlier defence system, which seems to have received its definitive lay-out at the beginning, but whose clayey earth-work was of rather modest dimensions. Its high date of foundation, circa 1900–1800 BC, permits us now to assert that there was both continuity (if not overlapping) and a tight conceptual relationship between the tumuli and the earlier “castellieri”.21 To the features common to the two series of structures we have discussed earlier, other elements may be added, still more pregnant with symbolism. Settlements obviously contained the dwellings of the living but they might also be used for the burial of selected individuals. From this point of view Sedegliano finds a perfect comparison, consistent also as regards chronology, in Monkodonja, where a considerable group of burials was discovered in a stone rampart near one of the entrances.22 In various European regions, such as Great Britain, the habit of burying the dead, or parts of them, in inhabited spaces is largely documented, especially in locations of particular importance, e.g. entrance and exit points. Thus earlier fortresses such as Sedegliano and Monkodonja seem to have been not only focal points in the landscape and places where life and death converged, but also meeting points for neighbouring communities which may have gathered there for the funerals of eminent people and other sacred ceremonies. In some way human remains might also “have been used to mark out the physical boundary between the local communities and foreigners”.23 Later on, during or at the end of the Middle Bronze Age, and increasingly so in the Late ! maybe more for the sake of visibility and showing off an elitist life-style than for real defence requirements !, more and more complex building solutions were adopted (such as the box-like technique), ramparts were greatly reinforced and heightened, and the amount of collective work became more and more remarkable.24

21

Càssola Guida, Corazza forthcoming; Càssola Guida forthcoming. Mihovili#, Hänsel, Ter$an 2005, 399; Hänsel, Mihovili#, Ter$an 2007. 23 Brück 1995, 256. 24 Càssola Guida, Corazza 2005. 22

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REFERENCES 1. BORGNA E. forthcoming, Individual Burials and Communal Rites: the Manifold Uses of the Monumental Architecture in the North-Adriatic Early Bronze Age, in Ancestral Landscapes: Burial Mounds in the Copper and Bronze Ages (Central and Eastern Europe - Balkans - Adriatic - Aegean, 4th-2nd Millennium BC), International Conference, Udine, May 15th-17th 2008. 2. BORGNA E., P. CÀSSOLA GUIDA 2007, At the Fringe of the Tumulus Culture: Bronze Age Tumuli of North-Eastern Italy between Europe and the Aegean, in I. GALANAKI, H. TOMAS, Y. GALANAKIS, R. LAFFINEUR, eds., Between the Aegean and the Baltic Seas: Prehistory across Borders, Proceedings of the International Conference held at the University of Zagreb, 11-14 April 2005 (“Aegaeum” 27), Liège - Austin, 191-201. 3. BORGNA E., P. CÀSSOLA GUIDA forthcoming, Sea-farers and landtravellers in the Bronze Age of northern Adriatic, 13th EAA Annual Meeting, Zadar 2007. 4. BRÜCK J. 1995, A place for the dead: the role of human remains in Late Bronze Age Britain, “PPS” 61, 245-277. 5. BUR(I)-MATIJA(I) K. 1989, Gradina Vr!in u okviru bron!anog doba Istre, “Arheoloski Vestnik” 39-40, 475-494. 6. CANCI A., P. CÀSSOLA GUIDA, S. CORAZZA 2005, Il Tumulo Protostorico di S. Osvaldo, Udine, in Papers in Italian Archaeology VI. Communities and Settlements from the Neolithic to the Early Medieval Period, Proceedings of the 6° Conference of Italian Archaeology held at the University of Groningen, Groningen Institute of Archaeology, The Netherlands, April 1517, 2003, vol. I, ed. by P. ATTEMA, A. NIJBOER, A. ZIFFERERO, BAR International Series 1452 (I), Oxford, 137-142. 7. CÀSSOLA GUIDA P. 2006, Nuove note di protostoria friulana, in S. CORAZZA, G. SIMEONI, F. ZENDRON, Tracce archeologiche di antiche genti. La protostoria in Friuli, Montereale Valcellina (Pordenone), 17-50. 8. CÀSSOLA GUIDA P. forthcoming, The Early Bronze Age in North-Eastern Italy: the Making of a Monumental Landscape, in Ancestral Landscapes: Burial Mounds in the Copper and Bronze Ages (Central and Eastern Europe - Balkans - Adriatic - Aegean, 4th-2nd Millennium BC), International Conference, Udine, May 15th-17th 2008. 9. CÀSSOLA GUIDA P., S. CORAZZA 2003, Il tumulo di Santo Osvaldo.“Alla ricerca dell’antenato”. Guida alla mostra, Udine. 10. CÀSSOLA GUIDA P., S. CORAZZA 2005, Dati recenti sull’assetto insediativo dell’alta pianura udinese fra età del bronzo e età del ferro, in Marchesetti e i castellieri 2005, 221-238. 11. CÀSSOLA GUIDA P., S. CORAZZA 2006, Dai tumuli ai castellieri: 1500 anni di storia in Friuli (2000-500 a.C.). IV, a cura di PAOLA CÀSSOLA GUIDA e SUSI CORAZZA, “Aquileia nostra” LXXVII, 297-314.

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12. CÀSSOLA GUIDA P., S. CORAZZA forthcoming, First clues as to the emerging of élites and long-distance relationships in the Upper Adriatic hinterland at the end of the Bronze Age, in Dall’Egeo all’Adriatico: organizzazioni sociali, modi di scambio e interazione in età postpalaziale (XII-XI sec. a.C.), Atti del convegno internazionale, a cura di E. BORGNA e P. CÀSSOLA GUIDA, Udine 1-2 dicembre 2006. 13. CÀSSOLA GUIDA P., E. MONTAGNARI KOKELJ 2006, Produzione di sale nel golfo di Trieste: un’attività probabilmente antica, in Studi di protostoria in onore di Renato Peroni, Firenze, 327-332. 14. &OVI) B. 1983, Regionalne grupe ranog bronzanog doba, in Praistorija jugoslavenskih zemalja, IV. Bronzano doba, Sarajevo, 114-190. 15. DE MARINIS R.C. 1999, Towards a Relative and Absolute Chronology of the Bronze Age in Northern Italy, “Notizie Archeologiche Bergomensi” 7, 23100. 16. FORENBAHER S. 1993, Radiocarbon dates and absolute chronology of the Central European Early Bronze Age, “Antiquity” 67, 218-220, 235-256 17. HÄNSEL B., K. MIHOVILI), B. TER*AN 2007, Radiokarbondaten zur alteren und mittleren Bronzezeit Istriens, “Prähistorische Zeitschrift” 82, 1, 23-50. 18. Marchesetti e i castellieri 2005, Carlo Marchesetti e i castellieri – 19032003, Atti del Convegno Internazionale di Studi, Castello di Duino, Trieste, 14-5 novembre 2003, a cura di G. BANDELLI e E. MONTAGNARI KOKELJ, Trieste 2005. 19. MASELLI SCOTTI F. et al. 1998, The region of Caput Adriae according to recent excavations at Castelliere of Elleri, in Proceedings of the XIII International Congress (Forlì, 8-14 settembre 1996), vol. IV, Forlì 1998, 765-770. 20. MIHOVILI) K. 1994, Preistoria dell’Istria dal Paleolitico all’età del Ferro, in Preistoria e Protostoria del Friuli-Venezia Giulia e dell’Istria, Atti XXIX Riunione Scientifica dell’Istituto Italiano di Preistoria e Protostoria (Trieste, sett. 1990), Firenze 1994, 101-118. 21. MIHOVILI) K. 1997, Fortifikacija gradine Gradac-Turan iznad Koroma!na / The fortification of Gradac or Turan hill-fort above Koroma!no, “Arheolo'ka Istra$ivanja u Istri” 18, 39-59. 22. MIHOVILI) K., B. HÄNSEL, B. TER*AN 2005, Moncodogno. Scavi recenti e prospettive future, in Marchesetti e i castellieri 2005, 389-408. 23. MONTAGNARI K OKELJ E. 1996, Articolazioni culturali e cronologiche. L’Italia settentrionale. Friuli Venezia Giulia, in L’antica età del bronzo in Italia, Atti del Congresso di Viareggio, 9-12 gennaio 1995, a cura di D. COCCHI GENICK, Firenze 1996, 63-66. 24. Museo di Muggia 1997, Il Civico Museo Archeologico di Muggia, a cura di F. MASELLI S COTTI, Trieste 1997. 25. RADMILLI A.M. 1988, Ancora su alcune recenti pubblicazioni di preistoria del Friuli-Venezia Giulia, “AttiSocPreistProtost FriuliVenezia Giulia” V, 1982-1986 (1988), 159-165. 26. STACUL G. 1972, Il Castelliere C. Marchesetti presso Slivia, nel Carso triestino, “RivScienzePreist” 27, 1, 145-162.

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27. STACUL G. 1982, Si continua a parlare favelle diverse, “AttiCivMuseiTrieste” 13, II, 27-31. 28. TECCHIATI U. 1998, Sot"iastel. Un abitato fortificato dell’età del bronzo in Val Badia, Bolzano. Figures

Fig. 1 – Distribution of tumuli in the Upper Friulian Plain.

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Fig. 2 – Sant’Osvaldo, Udine: view of the tumulus before the excavations.

Fig. 3 – Sant’Osvaldo, Udine: the pebble core and the grave.

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Fig. 4 – 14C test on a bone sample from the tumulus of Sant’Osvaldo, Udine.

Fig. 5 – Sedegliano (Udine): plan and aerial view of the castelliere.

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Fig. 6 – Sedegliano (Udine): stratigraphic section of the rampart. At the base, the tombs cut into the earlier clayey earth-work are discernible.

Fig. 7 – Sedegliano (Udine): view of Tomb 1.

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Fig. 8 – 14C test on a bone sample from Tomb 1 of Sedegliano (Udine).

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Fig. 9 – Distribution of castellieri in Friuli, Venezia Giulia and Istria (the Early Bronze Age settlements quoted in the text are marked with red dots).

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SERPENTINITE SHAFT-HOLED AXES IN THE CAPUT ADRIAE: PRELIMINARY RESULTS AND PERSPECTIVES BASED ON X-RAY COMPUTERIZED MICROTOMOGRAPHY FEDERICO BERNARDINI*, EMANUELA MONTAGNARI KOKELJ*, NICOLA SODINI**, DIEGO DREOSSI**, STEFANO FAVRETTO**, GABRIELLA DEMARCHI***, ANTONIO ALBERTI***, FRANCESCO PRINCIVALLE*** * Dipartimento di Scienze dell’Antichità, Università degli Studi di Trieste, I ** Dipartimento di Scienze della Terra, Università degli Studi di Trieste, I *** Elettra, Sincrotrone Trieste In this paper shaft-holed axes made from serpentinites are taken in consideration due to their abundance in the archaeological records. The preliminary results of petrographical analysis of stone artefacts and the main natural serpentinite outcrops in the Eastern Alps are succinctly described. Moreover a special attention is given to a test by X-ray computed microtomography performed on a small serpentinite core extracted from an axe in order to understand the potential of this method in the study of polished stone artefacts.

1. Introduction “Greenstone” is the term commonly used in archaeology to define lithologies for the most part homogeneous as to geological genesis, i.e. HP metaophiolites (eclogites, jades, omphacite schists, glaucophane schists, serpentinites, etc.), utilised in prehistory to produce polished artefacts of different typology and destination, but mainly axe blades. The exhibition Le vie della pietra verde organized in 1996 in Turin marked a renewed interest for greenstone: the exhibition was the final step of a project which, with a fairly innovative approach, had been set up to analyse the relationship between the geological occurrences of greenstone and the archaeological sites where polished materials document their exploitation from the Early Neolithic to the Bronze Age in particular in Northern Italy, but with Europe in the background [12]. These studies combined “hard” and “soft” sciences – i.e. geology, petrography, chemistry and archaeology (including typological, technological and wear-traces analyses) –, with the purpose of understanding the different functional and symbolic uses of polished artefacts in the context of specific cultural and socio-economical exchange mechanisms.

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Also Friuli-Venezia Giulia entered into the project, and interdisciplinary research focused on two main topics: one of the most numerous groups of artefacts found in Northern Italy, over 300 at the time of the study, composed mainly of axe blades, from a single open-air site, Sammardenchia (Udine), dated mostly to the Early Neolithic [4, 20]; a much smaller sample of typologically different materials, originally 21 shaft-holed axes, collected in different sites of the region, but with a relatively high concentration in the Trieste Karst, presumably datable to the Copper Age. Among many other interesting results of these studies, a striking difference emerged in terms of provenance of the raw materials used to produce axe blades and shaft-holed axes respectively: mostly jades and eclogites from north-western Italy for the former, other rocks – primarily metaultramafites and serpentinites – presumably of non-Italian origin for the latter. This element was considered worthy of further investigation, and shaftholed axes were chosen for a new, international project started in 2004 [17, 7, 18]. 2. Basic archaeological and archaeometrical data on shaft-holed axes The first lot of 21 shaft-holed axes from Friuli-Venezia Giulia had undergone preliminary analyses only with stereomicroscopy and XRD [6]; in the following years other pieces were added, totalling to 28, and more sophisticated techniques – thin sections and SEM – were applied [5]. This advance in the archaeometrical field was accompanied by a precise archaeological orientation. In fact, in order to verify the likely non-Italian origin of the materials resulting from these studies, a preliminary test was made on artefacts from one of the famous pile-dwellings of Ljubljansko Barje, near Ljubljana (Slovenia): the site was chosen on the grounds of sound cultural similarities with several Trieste Karst caves indicated, at that time, mainly by classes of materials other than polished artefacts. 26 pieces (mostly, but not all, shaft-holed axes) were analysed through stereomicroscopy and XRD [19, 5], and the encouraging results suggested to expand the research to areas to the east of Friuli-Venezia Giulia, Slovenia and Croatia first. The main data obtained since the new international project was launched in 2004 can be summarized as follows: - in the investigated regions the serpentinite shaft-holed axes (Fig. 1) are very numerous, and prevail in Friuli-Venezia Giulia and in central Slovenia (Fig. 2). Their distribution partially overlaps with that of the doleritic artefacts in the Istrian peninsula, although their abundance quickly decreases from north (about 60%) to south (about 20%);

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- axes made of partially recrystallized doleritic basalt are rare in central and western Slovenia, totally absent in Friuli-Venezia Giulia and relatively abundant in Istria and in southern Slovenia. It has been recently demonstrated that the most probable provenance area of doleritic basalts is the Banija Ophiolite Complex in the Balkans [3]; - another group of these artefacts is made of metamorphosed ultramafic rocks: they are common in the Trieste Karst and in the Ljubljansko barje area, rare in Friuli and Istria (Fig. 2). For these last lithotypes, a provenance from the Eastern Alps has been suggested by D’Amico et al. [5]; - shaft-holed axes made from different and often local rocks, as carbonatic or pyroclastic lithologies, are less frequent. Rare artefacts from Friuli-Venezia Giulia are made also from gabbros and amphibolites [5]. As just indicated, serpentinite resulted to be the rock most frequently used to manufacture shaft-holed axes: consequently, for this and other reasons that will be presented below, field research and new technologies have recently focused on this raw material.

Figure 1. Serpentinite shaft-holed axe from Ljubljanica river (central Slovenia; length: 125 mm)

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3. Serpentinite shaft-holed axes in the Eastern Alps: materials and methods Archaeometrical analyses have been performed, in order to try to discover the raw material sources of serpentinite shaft-holed axes. About 50 artefacts from Friuli-Venezia Giulia, Slovenia and Istria have been analyzed by OM and/or XRD [6, 19, 1, 2].

Figure 2. 1. Serpentinite outcrops sampled in the Eastern Alps: 1, SBUC (Slovenska Bistrica Ultamafic Complex, Pohorje, Slovenia); 2, Bernstein, Steinbach, Badersdorf (Burgenland, Austria); 3, Pernegg (Styria, Austria); 4, Kraubath (Styria, Austria); 5, Hochgrössen (Styria, Austria); 6a: Stubachtal, 6b:

230 Felbertal, 6c: Hintersee, 6d: Kals, 6e: Möll Valley, south of Heiligenblut (Hohe Tauern, Austria). The dotted area corresponds to the zone where the studied serpentinite axes were found. 2. Serpentinite shaft-holed axes in the Caput Adriae: 1: S. Tomè (PN, Friuli-Venezia Giulia), n. AQ9514; 2: Meduno (PN, Friuli-Venezia Giulia), n. AQ250607; 3: Gradisca di Provesano (PN, Friuli-Venezia Giulia), n. AQ221855; 4: S. Eliseo di Caporiacco (UD, Friuli-Venezia Giulia), n. AQ223078; 5-20: Sammardenchia (UD, Friuli-Venezia Giulia), nn. AQ225152, AQ223082; AQ225170, SAM6, SAM90, SAM143, SAM148, SAM211–SAM213, SAM216, SAM301, SAM306, SAM315; Pozzuolo del Friuli (UD, Friuli-Venezia Giulia) nn. AQ116005, AQ223080; 21: Pavia di Udine (UD, Friuli-Venezia Giulia), n. AQ225151; 22: Castions di Strada (UD, FriuliVenezia Giulia), n. AQ232515; 23: S. Stefano Aquileiese (UD, Friuli-Venezia Giulia), n. AQ455715; 24: Novacco (UD, Friuli-Venezia Giulia), n. AQ331243; 25-26: Mossa (GO, FriuliVenezia Giulia), n. 1325, no number; 27: Nova Gorica (western Slovenia), no number; 28: Opicina (TS, Friuli-Venezia Giulia), no number; 29: Montedoro (TS, Friuli-Venezia Giulia), n. TS2280; 30: Grotta Sottomonte (TS, Friuli-Venezia Giulia), n. TS25785; 31: S. Ivan pod Sterne (Istria, Croatia), n. P-194; 32: Sandaya (Istria, Croatia), P-15059; 33-34: Istria (Croatia), nn. P-12, P-14; 35-38: Ljubljanica (Ljubljansko barje, Slovenia), nn. 8, 9, 11, 12; 39-48: Deschmann Pile-dwellings (Ljubljansko barje, Slovenia), nn. B45, B46, B48, B50, B52, B54, B56, B59, B60, B62.

The mineralogical and petrographic data show that the serpentinite axes are generally very similar. They all are characterized by a not pseudomorphic texture - interpenetrating or interlocking - and are composed of fine to mediumgrained antigorite, various amounts of magnetite in irregular aggregates or local nets, and frequent clinopyroxenes relics variably replaced by antigorite (Bernardini et al. 2008). A comparative procedure has been adopted to identify their provenance area, following the approach used also by other scholars [13, 22]. Natural serpentinite occurrences in the Eastern Alps have been explored because of their closeness to the discovery sites and the indications of previous studies (Fig. 2). The serpentinite geological samples collected from the outcrops in north-eastern Slovenia (Pohorje area; [23]), Burgenland (eastern Austria, close to the border with Hungary; [8, 11]), Styria and the Hohe Tauern (central Austria; [16, 15]) have been considered. Both the mineralogical and petrographic features of serpentinite axes are markedly different from those sampled from the outcrops of the Slovenska Bistrica Ultramafic Complex (SBUC), in the south-eastern region of the Pohorje Mountains. The Metaultrabasites of this district constitute a small body some 5x1 km in size composed of serpentinized harzburgites, with local lenses or pods of garnet lherzolites [9, 10, 21, 23]. Thus we can exclude the Pohorje rocks as a source area. The preliminary study of the serpentinites collected from other localities in the Eastern Alps, and the bibliographic data, show that the studied tools are similar to the rocks that outcrop in the Hohe Tauern, in particular to some serpentinites from the Blauspitze Mountains near Kals in the Matrei Zone (Eastern Tyrol), and from the upper Möll Valley, south of Heiligenblut (Carinthia). The metaultrabasites from the Matrei Zone are transformed into

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antigorite serpentinites characterised by interpenetrating and mesh textures. The primary clinopyroxene is replaced by aggregates of tremolite, chlorite and carbonate; metamorphic diopside has also been observed [16]. Therefore the latter localities can be considered possible candidates as source areas for the Ljubljanica artefacts. 4. Preliminary test by X-ray computed microtomography The determination of provenance of serpentinites meets with problems deriving from: their occurrence in many places; their close similarity as for mineralogical composition; the scarcity of detailed studies on their composition. The features which are proving to be useful in the characterization of serpentinites are: occurrence/absence of relic minerals and their type; rock texture pseudomorphic or not pseudomorphic -; type and distribution of accessory minerals. Optical microscopy indicates that rock texture, type and distribution of accessory minerals, occurrence/absence and distribution of relic minerals are crucial aspects for the identification of provenance. In order to obtain more information about these elements, a test using the X-ray computed microtomography on a core of a few mm across from a serpentinite shaft-holed axe has been carried out at Tomolab laboratory at Sincrotrone Trieste (Basovizza, Trieste). X-ray computed micro-tomography (µ-CT) is a non-destructive imaging technique that produces a three dimensional digital map of an object. The distribution of regions with different density and/or chemical composition inside the sample can be visualized by means of virtual slicing or using 3D volume rendering. The main Tomolab component are: the micro-focus X-ray tube which operates at high energy (40 ÷ 130 kVp) with a minimum focal spot size of 5 µm, the motorized sample stage and the detector (see figure 1). The detector is a 12/16 bit CCD camera (Photonic Science, X-Ray Imager VHR) which provides a good combination between a large field of view (50.1 mm ! 33.4 mm) and a small optical pixel size (12.5 x 12.5 "m2). The CCD is coupled via a fiber optic taper to a GOS screen. The cone-beam geometry allows studying centimetersized samples and the maximum spatial resolution achievable is determined by the focal spot size (Fig. 3). The potential of this method was proved concerning the three-dimensional visualization of the inner texture of the samples. The identification of different mineralogical species can be obtained from 2-dimensional slices as well as from the whole 3-dimensional digital volume, and their geometrical and morphological characterization is then possible.

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Figure 3. Scheme of µ-CT set-up and a photo of Tomolab.

The sample for the test has been taken from a serpentinite shaft-holed axe from Castions di Strada (UD; inventory number: AQ232515). A micro-core with a diameter of 6 mm was extracted from the axe in the previous studies; part of it has been used to obtain a thin section. The rock is characterized by a planar foliated fabric marked by opaque minerals and relic clinopyroxenes. The images acquisition parameter are shown in Fig. 4. In the 2-dimensional slices obtained by the analysis it is possible to identify 3 different gray gradations areas and a mixed one (Fig. 4). These differences are linked to the different behaviour of 3 components with dissimilar absorption levels. The grey value inside the coloured squares has been analysed. The lighter most absorbent zones have the higher absorption coefficient and probably the higher density. To measure the different gray gradations the 3 selected zones have been analysed separately.

Figure 4. The 3 different gray gradations areas and the mixed one on a 2-dimensional slice of the core.

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Figure 5. The 3 different gray gradations zones and the respective histograms of gray value distribution and profiles with the value trend through the squares.

The histograms in the Fig. 5 show the grey value distribution in the 3 zones, while the profiles on the right are the grey value trend through the squares. The mixed zone includes zones 1-3 (Fig. 6).

Figure 6. The mixed zone is a combination of zones 1-3.

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The zone 1 corresponds to the opaque minerals; the zone 2 to the serpentine matrix and the zone 3 to CPX relics. In addition to the mineral identification, thanks to the 3 dimensional rendering the sample can be virtually cut in any plan or direction in order to investigate the inner texture and structure (Fig. 7). Moreover with the segmentation process is possible to visualize separately each component with a different phase (Fig. 8).

Figure 7. Views of the sample along 3 different directions. At the bottom on the right a 3dimensional rendering of the sample.

Figure 8. On the left the more absorbent component has been removed; on the right only the more absorbent component is visible.

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5. Conclusions The majority of serpentinite shaft-holed axes from Friuli-Venezia Giulia, Slovenia and Istria shows similar mineralogical and petrographic features: almost all the samples display a non pseudomorphic texture constituted by an antigoritic serpentine matrix, generally very fine, clinopyroxene relic minerals and Fe-Ti oxides, often arranged in isolated aggregates. On the base of a comparison with the main serpentinite outcrops in the Eastern Alps, the Hohe Tauern area (Central Austria) can be considered a possible candidate as source zone for the artefacts. Tomolab is a very useful tool to study the texture, the presence and the distribution of relic minerals and Fe-Ti oxides in serpentinite rocks. The potential of this method was proved concerning the 3-dimensional visualization of the inner texture of the core of the serpentinite. The identification of different mineralogical types and their geometrical characterization are then possible. In the future it could be possible to perform analysis directly on the axes surface without taking any material, considerably improving the efficacy of the method.

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a new research project, in Atti della XXXIX riunione dell’Istituto Italiano di Preistoria e Protostoria, 713-25 (2006). D. Peloi, Le asce-martello in pietra levigata: proposta di lettura analitica ed esempi applicativi a contesti del Friuli Venezia Giulia e della Slovenia. B. Sc. Thesis, Università degli Studi di Trieste (19961997). A. Pessina and C. D’Amico, L’industria in pietra levigata del sito neolitico di Sammardenchia (Pozzuolo del Friuli, Udine). Aspetti archeologici e petroarcheometrici, in Sammardenchia - Cueis. Contributi per la conoscenza di una comunità del primo Neolitico (eds. A. Ferrari, A. Pessina), 23-92, Edizioni del Museo Friulano di Storia Naturale, 41, Udine (1999). R. Sassi, C. Mazzoli, C. Miller and J. Konzett, Geochemistry and metamorphic evolution of the Pohorje Mountain eclogites from easternmost Austroalpine basement of the Eastern Alps (Northern Slovenia). Lithos, 78, 235-261(2004). J. Skoczylas, E. Jochemczyk, E. Foltyn and E. Foltyn, Neolithic serpentinite tools of west-central Poland and upper Silesia, Kristalinikum, 26, 157-166 (2000). M. Vrabec, J.C.M. De Hoog and M. Janak, Origin of UHP garnet lherzolite and serpentinised harzburgites from Pohorje, Eastern Alps, Slovenia, Geochimica et Cosmochimica Acta, 71, (15S), a1075 (2007).

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MUMMIES – A SPECIAL REPORT RESULTS OF CAT SCAN ANALYSES OF EGYPTIAN MUMMIES IN THE CIVICO MUSEO DI STORIA ED ARTE OF TRIESTE MARZIA VIDULLI TORLO Civico Museo di Storia ed Arte di Trieste, via della Cattedrale 15, Trieste, Italy

Introduction The opportunity to subject three human mummies and those of animals to a CAT scan came after they were moved to the City Museum of History and Art in Piazza della Cattedrale. Before 2004 only one human mummy was exhibited in this museum whilst the other two and the crocodile mummies were exhibited in the City Museum of Natural History in Piazza A. Hortis. On this occasion Dr. Fulvio Costantinides, a well-known forensic doctor, thought it would be a good idea to examine the three mummies in more depth. His proposal was greeted with great enthusiasm by the Department of Radiology at the Maggiore Hospital in Trieste, directed by Dr. Paolo Cortivo. Dr. Fabio Cavalli, a radiologist and medical historian willingly gave his time, professionalism and enthusiasm. The happy circumstance was the arrival at the Maggiore Hospital of one of the latest generation of Toshiba S16 Aquilion CT scanners. CAT Scanning CAT scanning has the great advantage of being non-invasive and, without intervening in any way on the mummy, it is able to provide information of great importance for the fields of Egyptology, Anthropology and Paleopathology, opening the way to subsequent fruitful researches and multidiscipline in-depth analyses which are indispensable for archaeology today. CAT is the acronym for Computerised Axial Tomography. Tomography means “representation in layers”, and with this method it is possible to get axial sections of the whole body from head to toe. The high definition CAT machine at the Maggiore Hospital can get a section every half a millimetre and, thanks to specific software, is able to reprocess the information and return images both from an orthogonal and threedimensional plane, which show in great detail not only the skeleton, but also the

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soft parts, the skin and the bandages enabling us to observe the resins and other details of the mummification. Furthermore it is possible to operate virtual endoscopies and “unwrap the body”, and all in a non-invasive way. The Results The three mummies from the City Museum offer an interesting case history and show different embalming techniques, which allow us to make comparisons and important observations. Two mummies date back to the XXI Dynasty, that is, about 3,000 years ago. We can give a precise date because of the presence in the mummified body of the viscera which were removed and treated and then put back in the abdominal cavity: this usage is typical only in this period when the placing of the viscera in Canopic jars was temporarily suspended. The third mummy is of a man of advanced years who lived in Egypt in the Greco-Roman period (between the 3rd century BC and the 1st century AD). The mummy of the priest Pa-sen-en-Hor

Figure 1. The mummy of the priest Pa-sen-en-Hor

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Figure 2. The mummy of the priest Pa-sen-en-Hor

The mummy of the priest, an exceptional case, is intact, still wrapped in its bandages. This mummy arrived in Trieste in the middle of the 19th century (given on 25th April 1867 to the museum by three Greek merchants, Ciriaco and Atanasio Vardacca and Stimati Zizinia) complete with its sarcophagus of stuccoed and painted wood, which in its turn contained a cartonnage covering, formed on the mummy, which in its turn was stuccoed and decorated. The analysis showed that among the bandages there is an adult male (about 30 to 40 years old), whose name, from the inscriptions on the sarcophagus, was Pa-sen-en-Hor, a priest who carried the incense in the temple of the god Ammon at Thebes, the city from where our find certainly came. The age was determined from cranial stitches, which have not been completely obliterated, while the clear occipital protuberances, like the pronounced bone ridges of the lower limbs, show that it was a man, as is also obvious from the genital organs (treated and well wrapped in bandages). The priest was 162 cms tall, he still had all his teeth, which however were in an advanced state of wear (this is common in Egyptian mummies and in our

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ancestors up to the Middle Ages and is most likely due to the chewing of hard foods which constituted the basis of their diet, or to the presence of grains of sand in the flour, a circumstance described by Herodotus). He also had a big cavity extending over two teeth caused by the eating of sweet foods and food rich in carbohydrates: this is uncommon and denotes a certain affluence, as such food was not available for the less well-off classes. There is also a large abscess on the incisor (which was fistulized on the outside): he certainly suffered from toothache. His head was mummified using plenty of liquid resin and bandages, but shows that the process was not carefully carried out: his brain had not been completely removed (residue of the encephalon can be seen on the cranium) but it was extracted in the usual way through the nose, after the staving in of the ethmoid bone with the traditional metallic hook. The CAT scan showed another unusual element: the lungs had not been removed, which, having collapsed, show up as a thin grey strip. A thick homogenous layer of warm resin was poured through a cut in the jugular to fill the thoracic cavity. The rest of the viscera, excluding the heart of course, were extracted, embalmed separately, carefully bandaged and replaced in the abdominal cavity. For this mummy it was possible to decide the presumed cause of death. The skeleton shows no lethal, traumatic lesions, but the widespread presence of Trichinella spiralis (a parasitic worm present in pigs and other wild animals, as well as occasionally in man, which comes from eating the lightly cooked meat of these animals) shows that the priest had contracted the parasite. The infestation had invaded the encephalon and the lungs, with secondary cardiac side effects: the CAT scan shows several small thick masses, which are the calcification created around the encysted larvae, which can be seen all over the muscles, the back, the lungs – where they are not completely calcified – and in the residue of the encephalon. His thickened and hypertrophic heart supports the theory that the cause of death was heart failure. The CAT scan, as had been shown by x-rays carried out in 1968, shows the presence, under the bandages, of some foreign bodies: in place of the eyeballs, replaced by two rolled up bandages, two circular concave plates made of baked clay or faience were inserted, probably painted so as to render realistically the eyes, which were removed during mummification. There was also a rectangular disk on the chest in the shape of a scarab: it was an amulet to protect the heart.

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The mummy of the woman, named Neferet, the Beautiful

Figure 3. The mummy of the woman, named Neferet, the Beautiful

The second mummy is that of a woman who had been treated with the best method of Egyptian embalming which took a long time, using the most careful techniques and the most expensive products, used lavishly. The cranium had been completely emptied and has an exceptionally thick smooth layer of resin (comparable with the mummy of the famous pharaoh Rameses) cast through the nose. The tongue remains, while the eyeballs have been replaced by bandages soaked in resin. Her teeth are intact, with no sign of decay, but the enamel is very worn, and there is a small abscess at the root of one of her teeth. She is about 30 years old, younger than the priest Pa-sen-en-Hor. All the viscera were removed, leaving the heart (small and healthy) in its place. The viscera were then put back as a compact coil after having been carefully treated. A small object in the shape of a circular lens with irregular sides of 2.5 cms was placed in her thorax, resting against the backbone: it was an amulet but its meaning is not easy to interpret: on the basis of its external profile, it could be an ugiat multiple eye, a sign of protection and purity. The x-rays carried out in 1951 had shown that the woman had been one and a half metres tall and had had children, whilst the CAT scan shows that, on the contrary, the particular opening of the pubic symphysis was due to a trauma suffered by the mummy, caused by the dislocation of the pelvis at the time of the disarticulation of the legs which happened after death. The exterior of the mummy shows the care taken by the mummifiers in restoring the body, and in particular the nails, after the long “soak” in natron (sodium salts which totally dehydrated the body and also had an antiseptic effect).

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The skin was then abundantly covered with balsam and this made it stiff and compact, thus making it difficult for desecrators to break. Unfortunately the mummy now has a complete disarticulation of the limbs and many lacerations in the bandages, almost certainly due to a quick “robbery” which we can assume was carried out by thieves during the time of the pharaohs, no doubt looking hastily for precious objects which had been put in among the bandages: heedless of the damage they would cause to the body, they had taken it out of its original box violently, removing the arms and legs and then abandoning it. No data has clarified the cause of death of this woman, who certainly belonged to the upper ruling class, but today we know neither her name nor her role in society. Unlike the priest Pa-sen-en-Hor, she was not preserved- in her own sarcophagus (perhaps the robbers had destroyed it in order to re use the parts in precious metal) but was found in one which originally belonged to another person, a priest and scribe called Pa-di-Ammon, whose body was not preserved. We can only imagine that when the 19th century researchers found the tomb they discovered many boxes and some bodies and they put one by chance, which was quite well-preserved, in a beautiful sarcophagus, perhaps in good faith or simply to get more for it when they sold it. We cannot, however, exclude the possibility that the exchange took place in ancient times: although, at the time of her burial, taking into consideration the richness of her embalming, the woman would have certainly had a sumptuous sarcophagus with her name engraved on it and been surrounded by precious objects. Moreover, and this fact is documented, when the priests of the XXI dynasty ascertained the deplorable state of a violated burial, they might have tried a “realignment”, which was respectable but very often random. This also happened to the mummies of the pharaohs who were put in sarcophaguses belonging to other pharaohs and then concealed all together in a hiding place; they were then discovered by chance in the 19th century by tomb raiders, then found by the police who saved the mummies and took them to the Museum in Cairo, where they can now be seen in a special section. This mummy too, with its sarcophagus which at the time was considered relevant (the exchange was only revealed in an x-ray taken in 1951), was donated to the Natural History Museum (then called the Ferdinando Massimiliano Zoological Museum) in 1867 by the three Greek merchants. In 1874 it was given to the newly opened City Museum of Antiquities (which is now the City Museum of History and Art) in consideration of its considerably antique value.

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The mummy of the old man Even though the third mummy is in a sarcophagus which dates from the XXI dynasty and belonged to a priestess whose name was not inscribed, it belongs to a more recent era: that of the Greco-Roman domination of Egypt. It is the mummy of an elderly man whose identity is unknown. His embalming was done roughly and in a hurry, which typical of that period when there was a widespread deterioration in technique. For example, inside his chest there are …. two extra ribs: material put in carelessly during the refilling, typical of a workshop which was working on many corpses at the same time, almost like an industrial “assembly line”, with no regard for the religious rites due to the dead. The morphological aspect of the jaw shows the man’s advanced age; he had had some teeth (this is shown by the obliterated dental alveoli) while other teeth had been lost after his death (alveoli still present); the only tooth he had left had serious decay. His brain had been removed, but a part had remained in the cranial cavity and a light layer of balsam can be seen, which was cast inside through the nose. The man still has hair and a beard. Now his head is separated from his body and some of the cervical vertebrae are disarticulated. The viscera had been treated and put back inside the chest. The mummy has had its bandages completely removed, which inclines us to think that the removal of the bandages, or as it was referred to in the past, the “opening” of the mummy, took place in Trieste, in the second half of the 19th century. If, as can be deduced from reading the data in the archives, this is the mummy donated by two men from Trieste, Francesco Mell and Ermenegildo Mazzoli, we can suppose that either the “event”, which at the time was a fashionable one, took place in one of their properties, or that - a more intriguing suggestion - it took place in their “shop” (they were retailers in medicines, paints, chemical preparations and dyeing products) with the scientific objective of observing and finding out about the materials and resins used in the ancient Egyptian art of embalming. We must not forget that throughout antiquity and up to the end of the 18th century the powder from mummies was used, among other things, in pharmacopoeia and was considered an excellent remedy for haemorrhages.

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Figure 4. A face from 3,000 years ago

The final surprise from the results of the CAT scan was the work of Dr. Cavalli who, putting all the anthropometric data into a software used mainly by forensic experts, obtained the virtual reconstruction of the face of the woman, at the young age of 20. A face brought back from 3,000 years ago, reconstructed with an excellent likeness thanks to the exceptional condition of the mummified head, whose soft parts and nose cartilage are also preserved. Being able to take part in the reappearance of this pretty face gave us the idea of giving a name to this mummy who had so far been anonymous: hence the name Neferet, that is the “beautiful”, recalling the names of Nefertari and Nefertiti, two famous women from the land of the pharaohs.

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Figure 5. The priest’s face

A similar process then revealed the face of the priest Pa-sen-en-Hor. He had regular features, only the end of his nose which was broken off during mummification is difficult to make out. Comparing this face to the cartonnage and sarcophagus masks showed a striking likeness and the nose a slight tendency to curve. References 1. Cavalli Fabio, Le mummie egizie del Museo Civico di Trieste attraverso l’analisi mediante TC ad alta definizione: modelli d’indagine e risultati Imaging in mummiologia ed antropologia fisica – Atti della giornata di studio, Gradisca d’Isonzo, 15 gennaio 2007, Accademia Jaufré Rudel di Studi Medievali 2008, p. 39-54 2. Marzia Vidulli Torlo, Speciale mummie: risultati delle analisi Tac alle mummie egizie dei Civici Musei di Trieste in “Atti dei Civici Musei di Storia ed Arte di Trieste”, n. 21 (2005) p. 175-190 3. Marzia Vidulli Torlo, Trieste e l’Egitto attraverso la Collezione egizia del Civico Museo di Storia ed Arte di Trieste, Imaging in mummiologia ed antropologia fisica – Atti della giornata di studio, Gradisca d’Isonzo, 15 gennaio 2007, Accademia Jaufré Rudel di Studi Medievali 2008, p. 35-38 4. Marzia Vidulli Torlo, Scopri l’Antico Egitto. Museo virtuale della collezione egizia del Civico Museo di Storia ed Arte di Trieste, CD multimediale e interattivo, cura scientifica e stesura testi

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ANGLE SOFTWARE FOR SEMICONDUCTOR DETECTOR GAMMA-EFFICIENCY CALCULATIONS AND POSSIBILITIES FOR ITS APPLICATIONS TO CULTURAL HERITAGE OBJECTS CHARACTERIZATION SLOBODAN JOVANOVIC*1,2 AND ALEKSANDAR DLABAC1 University of Montenegro, Faculty of Sciences Cetinjski put bb, MNE-81000 Podgorica, Montenegro, and 2 Centre for Eco-toxicological Research of Montenegro Put Radomira Ivanovica 2, MNE81000 Podgorica, Montenegro 1

The ANGLE software for semiconductor detector efficiency calculations in its various forms has been in use for 15 years now in numerous gamma-spectrometry based analytical laboratories all around. It goes about a semi-empirical approach, which combines advantages of both absolute and relative methods to determining sample activity by gamma-spectrometry, while conciliating and minimizing their drawbacks. The physical model behind is the concept of effective solid angle – a parameter calculated upon the input data on geometrical, physical and chemical (composition) characteristics of (1) the source (incl. its container vessel), (2) the detector (incl. crystal housing and end-cap) and (3) counting arrangement (incl. intercepting layers between the latter two). It was shown earlier that only simultaneous differential treatment of gamma attenuation, counting geometry and detector response – as is the case with ANGLE – is essentially justified for this type of calculations. Attempting the other-wayround, i.e. to separately calculating these three phenomena, generally lead to (over)simplifications, which further require complex corrections with limited success. The program can be applied to practically all situations encountered in gammalaboratory practice: point, disc, cylindrical or Marinelli samples, small and large, of any matrix composition. No standards are required, but a start-up “reference efficiency curve” should be obtained (“once for ever”) by measuring a set of calibrated point sources at a large source-to-detector distance (e.g. 20-30cm, to avoid true coincidence effects). Calibration sources are chosen to cover gamma-energy region of analytical interest (e.g. 50-3000keV). This initial effort is largely paid back in future exploitation. As a summary, ANGLE is characterized by (1) a broad application range, (2) pretty fair accuracy for this type of calculations (of a few percent order), (3) comfortable data manipulation (under WINDOWS), (4) short computation times, (5) flexibility in respect with input parameters and output data, including easy communication with another software and (6) suitability for didactical/training purposes.

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ANGLE frame is also convenient to accommodating other efficiency calculation methods of semi-empirical or absolute type, Monte Carlo for instance. In addition, it is a matter of little effort to extend its existing scope of applicability to further/particular user’s needs and/or fields of interest (can be regarded as “open-ended” computer code). For radiation protection purposes, the possibilities of applying ANGLE to, inter alia, cultural heritage objects characterization (e.g. by neutron activation analysis) – based on semiconductor detector gamma-spectrometry measurements of waste samples – are selfexplaining from the general characteristics of the software here described. Samples of various origin, composition, size (bulky included), shape and (in)homogeneity can be used on a routine basis to this aim. KEYWORDS: ANGLE software; semiconductor calculations; cultural heritage characterization.

detector

gamma-efficiency

Introduction In any gamma-spectrometric measurement with semiconductor detectors, the question of converting the number of counts (collected in a full energy peak) into the activity of the sample/source cannot be avoided. There are, in principle, three approaches to this issue:

______________________________ * Presenting author, e-mail: [email protected] 1) Relative, where one tries to imitate as good as possible the source by a standard (or vice versa), while keeping the same counting conditions for the two. Paid enough care, the result is, in general, so accurate that cannot be surpassed by other methods. However, we all know what "enough care" means in practice. Combined with the inflexibility in respect with varying source&container parameters (shape, dimensions, material composition), this represents raison d'être of the other approaches, as follows. 2) Absolute calculations (Monte Carlo methods) yield full energy peak efficiency (εp) for a given counting arrangement. It is essentially statistical treatment of the events which photons undergo - from being emitted by a source atom until the interaction with the detector active body - including the treatment of the so produced electrons, positrons and other subsequent energy carriers. This approach is beautifully exact, on condition that we consider sufficiently large number of incident photons, and that we know the details about (i) source, detector and intercepting layers' geometrical&compositional data, (ii) the corresponding photon attenuation coefficients, (iii) energy and angle dependent cross section for various photon interactions with the detector active body, and (iv) parameters characterizing electron/positron behaviour in the latter. At

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present, inherent statistical uncertainty of Monte Carlo methods, unsatisfactory manufacturers' detector specifications and relatively poor knowledge of (some of) the above physical parameters are the limiting factors for its applicability. However, with speeding up of computers, and with more accurate detector specifications and cross section data (the determination of which is, on its turn, related to more careful and sophisticated measurements), it is reasonable to assume that the time works for absolute methods, and that in future they might be the dominant ones. 3) Semiempirical models, trying to conciliate the previous two. Semiempirical models commonly consist of two parts: (i) experimental (producing one kind or another of reference efficiency characteristic of the detector) and (ii) relative-to-this calculation of εp. Inflexibility of the relative method is avoided in this way, as well as the demand for some physical parameters needed in Monte Carlo calculations. Numerous variations exist within this approach, with emphases either to experimental or to computational part. Most of them simplify (or oversimplify) the physical model behind, i. e. the treatment of gamma-attenuation, geometry and detector response. Moens et al.13 showed that only the simultaneous differential treatment of these three factors is essentially justified. This fact is transformed into the concept of the effective solid angle ( Ω ), a calculated value incorporating the three components, and closely related to the detection efficiency (see further). Theoretical Given a gamma-source (S) and a semiconductor detector (D) (Fig. 1.), the effective solid angle is defined as1,2:

Ω=

∫ dΩ

(1)

VS , S D

with VS= source volume, SD= detector surface exposed to the source ("visible" by the source) and

dΩ =

Fatt ⋅ Feff ⋅ TP ⋅ n u TP

3

dσ

(2)

Here T is point varying over VS, P point varying over SD, and nu the external unit vector normal to infinitesimal area dσ at SD. Eq. (1) is thus a five fold integral. Factor Feff accounts for gamma attenuation of the photon following the direction TP out of the detector active zone, while Feff describes the probability of an energy degradable photon interaction with the detector material (i.e. coherent scattering excluded), initiating the detector response. The two factors

250

include therefore geometrical and compositional parameters of the materials traversed by the photon. With εp being proportional to

εp

Ω , the detection efficiency is then found as: Ω = ε p,ref (3) Ωref

where index "ref" denotes reference counting geometry to which the actual one is relative. So as to apply this method the following should be known: · reference efficiency curve, usually obtained by counting calibrated point sources at a reference distance (e. g. 15-20 cm), and covering gamma-energies (Eγ) in the region of interest (e. g. 50 -3000 keV);

·

·

considerable effort should be put in this phase to reach accurate ε p,ref(Eγ) function, but it pays off in further exploitation; geometrical and compositional data about the source, detector and all intercepting layers (for the latter e.g. source container and holder, detector end cap and housing, dead layers, etc.); gamma-attenuation coefficients for all materials involved.

For a cylindrical source coaxially positioned with the detector, and with radius smaller than that of the detector (ro
[

]

32

(4) In the above, five fold integral is reduced to four fold due to axial symmetry. Disk and point sources are included in Eq. (4) (for L=0, and L=0, ro=0, respectively).

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Fig. 1. To the definition of the effective solid angle ( Ω )

Fig. 2. Cylindrical source (ro
For sources with radii larger than that of the detector (ro>Ro, Fig. 3.):

∫ dΩ + ∫ dΩ =

Ω=

V1 ,S1

V2 ,( S1 +S 2 )

ro Ro π Fatt ⋅ Feff ⋅ R dR 4 ( ) d l dl r dr d + φ 2 ∫ ∫0 ∫0 ∫0 R 2 − 2 Rr cos φ + r 2 + (d + l ) 2 ro L 0 L

= +

[

]

32

+

ro φo L 0 Fatt ⋅ Feff ⋅ (r cos φ − Ro )dh 4 Ro dl r dr d φ 2 2 ∫0 −∫H R 2 − 2 R r cos φ + r 2 + (d + l − h) 2 ro − Ro L ∫0 R∫o o o

(

)

[

with

r 2 − Ro2 φo = φo ( r ) = arctg Ro Marinelli geometry (Fig. 4.) can be described by:

]

32

(5)

∫ dW + ∫ dW + ∫ dW + ∫ dW +

W=

( V1 +V2 ), S1

= + +

+ +

V2 , S 2

V3 , S1

r L + (r - rj )Lj 2 o

2

4 Ro r L + (ro2 - rj2 )Lj 2 o

4 r L + (r - rj )Lj 2 o

2 o

2

4 Ro 2 ro L + ro2 - rj2 Lj

(

)

-4 2 ro L + ro2 - rj2 Lj

(

ro

L

4 2 o

(V3 +V4 ), S 2

)

∫ dW = V5 ,( S 2 + S 3 ) Ro

p

∫ ( d + l )dl ∫ r dr ∫ df ∫ 0

0

0

ro

fo

0

0

Ro

0

-H

d

ro

p

Ro

rj

0

L

0

∫ dl ∫ r dr ∫ df ∫ [R ∫ l dl ∫ r dr ∫ df ∫ 0 d

∫j

d -L

-H

∫j

d -L

Fig. 3. Cylindrical source (ro>Ro)

0

ro

fo

rj

0

Fatt × Feff × R dR

[

R 2 - 2 Rr cos f + r 2 + ( d + l ) 2 Fatt × Feff × (r cos f - Ro )dh

2 o

- 2 Ro r cos f + r 2 + ( d + l - h ) 2 Fatt × Feff × R dR

(R

2

- 2 Rr cos f + r 2 + l 2

∫ [R

-H

)

3 2

]

3 2

2 o

- 2 Ro r cos f + r 2 + (l - h ) 2

ro

p

Ro

rj

0

0

(l + H )dl ∫ r dr ∫ d f ∫

+ +

+

Fatt × Feff × (r cos f - Ro )dh

0

dl ∫ r dr ∫ d f

]

3 2

]

3 2

+

Fatt × Feff × R dR

[R

2

- 2 Rr cos f + r 2 + (l + H ) 2

Fig. 4. Marinelli geometry

Computer code description The above effective described solid angles and corresponding detector efficiencies are calculated by our ANGLE software4-6. Its main screen is shown

]

3 2

(6)

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in Fig. 5, with input data being entered within five main sections (Detector, Container, Geometry, Source and ‘Other’). Detector, container and geometry windows are organized in the same way: at the left-hand side names of previously created detector (or container, or geometry) files are listed. Each of them contains all necessary data characterizing the detector (or container, or geometry). When, for instance, a new detector is being introduced, one first chooses its type: closed end coaxial HPGe, true coaxial HPGe, closed- or open-end coaxial Ge(Li), planar LEPD or well type. Program then asks for numerical values of the parameters characterizing the type chosen (crystal dimensions, including core or hole, dead and contact layers, end cap, inner housing, beryllium window, antimicrophonic shield, etc.). Entering these data is facilitated by multicolor illustrations at which current parameter is visually emphasized (Fig. 6).

Fig. 5. ANGLE main window

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Fig. 6. Entering the data for a new detector

For the source container the procedure is similar. When creating new container file, we choose between cylinder or Marinelli type (Fig. 7.). Follows entering of geometrical and compositional data characterizing the container.

Fig. 7. Entering the data for a container

Similarly, for a new geometry, we enter geometrical and compositional data about the source holder. Source itself is characterized by its height in the container (and radius if there is no container to determine it) and material composition. When the material composition is being entered - not only for the source itself, but also for any material of the source container, holder, intercepting layer

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or detector, the same subroutine is activated: one can choose between a few most encountered ones (air, water, plastic, aluminum), or introduce a new one. In the latter case, any composition is acceptable (pure element or compound, or mixtures). It is assumed that percentages of the major constituents are known (at least roughly), as well as their chemical formulae. These data, together with gamma attenuation coefficients, are used to calculate attenuation factors. Attenuation coefficients are found in an extensive (per element and per energy) data file. In the ‘Other’ window there are: Gamma energies of interest. We can give a set of energies from a previously created file, or create new one. Gauss coefficient order for numerical integration procedure (see Theoretical). The higher the order, the more precise is the result, but the computation time is longer. Language. English as the program communication language can be replaced by any other one, simply translating message-by-message. Reference efficiency curve, as in Fig. 8.

Fig. 8. Creating a reference efficiency curve

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At the output, calculated effective solid angles and full energy peak efficiencies are found per gamma energy given (Fig. 9). Output files can be handled in common way and are suitable for further programming. Possibilities for applying ANGLE to characterization of cultural heritage objects ANGLE is particularly suitable for application in neutron activation analysis (NAA), which is a powerful analytical tool (multielement analysis) in cultyral heritage characterization. Coins, cheramics, stones, soils, etc. can be analysed for up to 60 elements simultaneously with accuracies of few percent order and sensibilities of ppm or even lower range. Practical verification In routine applications accuracies of 3-4% are obtained, and not worse than 7% for the most unfavourable geometries (bulky samples at the detector top)5-6. These uncertainties originate for the most part from (i) the reference efficiency curve and (ii) poor detector specifications2,5,8, while (iii) contribution of computation error is negligible.

Fig. 9. ANGLE output file

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Conclusion We can summarize the main features of the here presented ANGLE code for calculation of semiconductor detector full energy peak efficiencies as: (i) broad application range, covering the vast majority of gamma-counting situations, including characterization of cultural heritage objects; (ii) good accuracy (uncertainties of the order of a few percent), based upon the concept of the effective solid angle; (iii) easy data manipulation with windows&menus; (iv) flexibility in respect with changing input parameters, and (v) didactical suitability (e.g. in gamma-spectrometry courses), since practically all parameters characterizing the detection process are found therein, systematically grouped and easy to follow and understand. It is also important to note that ANGLE frame can be readily adjusted to accommodating some other semiempirical or Monte Carlo methods for efficiency calculations. References 1. L. Moens, Ph.D. Thesis, University of Gent (Belgium), 1981. 2. L. Moens, J. De Donder, Lin Xilei, F. De Corte, A. De Wispelaere, A. Simonits, H. Hoste, Nucl. Instr. Meth. Phys. Res., 187 (1981) 451. 3. L. Moens, J.Hoste, Int.J.App.Radiat.Isotop., 34 (1983) 1085. 4. www.adlabac.users.cg.yu/angle2_120exe 5. S. Jovanovic, A. Dlabac, N. Mihaljevic, P. Vukotic, J.Radioanal.Nucl.Chem., 218 (1997) 13-20 6. N. Mihaljević, S. Jovanović, F. De Corte, B. Smodiš, R. Jaćimović, G. Medin, A. De Wispelaere, P. Vukotić, P. Stegnar, J. Radioanal. Nucl. Chem., Articles, 169 (1993) 209. 7. L.Moens, K.Debertin, Nucl. Instr. Meth. Phys. Res., A238 (1985) 180. 8. K. Debertin, G. R. Helmer, Gamma- and X-Ray Spectrometry with Semiconductor Detectors, Elsevir Science Publishers B.V., Amsterdam (1988).

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HOMINID FOSSILS AS UNIVERSAL AND NATIONAL CULTURAL HERITAGE: AN ESSAY ON PAST AND PRESENT ATTITUDES TOWARDS THE OWNERSHIP OF HOMINID FOSSILS AND THE QUESTION OF REPATRIATION• PHILLIP V. TOBIAS School of Anatomical Sciences, University of the Witwatersrand, Institute of Human Evolution, Johannesburg, South Africa The ownership of fossils, and for purposes of this paper I refer to that of hominid fossils, was long assumed to be vested in the individuals who made the discoveries. The author reviews here a series of case histories with which he has had direct or indirect personal contact, that illustrate claims for ownership. Some have been explicit, some implicit. They are drawn from South Africa, East Africa, North Africa, England, France, Germany, Italy, Russia, The Netherlands, Indonesia and China. This historical essay reviews the replacement of this practice by a policy that fossils are not seen as personal property, but as part of the heritage of the country of origin. During the colonial era, many specimens were removed from former colonies to the "home countries", where they remained for decades, at least until the subject territories attained their independence from the former imperial powers. The new policy about ownership, in such cases, entails the return (repatriation) of the expatriate fossils to the source country. Examples of success stories and of tardy responses are given. A policy for the future is set forth.

1. Raymond Dart and Taung Historically, the Taung child skull provided the world's first evidence that early hominids* had evolved in Africa and what manner of creatures they were. It was important not only as a beautiful and well-preserved specimen, but because, historically, this child skull of what Raymond Dart called Australopithecus africanus effected a revolution in our understanding of human evolution. Its •

*

Paper submitted at the “International Workshop on Science for Cultural Heritage”, ICTP, Trieste, 23-28 October 2006.

"Hominid" (a member of the Hominidae) has been used almost universally for the family of humankind for the last century. Molecular data have shown that apes are genetically so close to living humans that it would be inappropriate for them to be classified as a separate family. Hence, for many evolutionists apes are also hominids. To distinguish those hominids that are most closely related to humans, many palaeo-anthropologists, especially English-speakers, have adopted the tribe "Hominini" (conventionally shortened to hominin) within Hominidae. However, numerous authorities continue to use "hominids" in the old sense, a usage that is followed here. There is as yet no consensus.

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geography was unexpected; its morphology was without precedent; the pattern of early hominid emergence that it compelled on us was at variance with what had been expected by the wise ones up to 1924 (the discovery year) and 1925 (the year in which Dart published the first account of it [4]). If there were doubt that humans had evolved from non-humans beforehand, the features of the Taung skull largely dispelled these uncertainties, although it took years for a sceptical community of scholars to accept Dart's claims. From the beginning Dart, who had achieved instant fame through the Taung find, assumed that he owned the Taung skull. Such visitors as Robert Broom, Ales Hrdlicka and Alfred Sherwood Romer enjoyed free access to the Taung skull, usually in Dart's office in the Wits anatomy department. For the Prince of Wales (later and briefly King Edward VIII), Dart took the skull to the old Cariton Hotel, Johannesburg, for the apprisement and delectation of the Prince. It was in Dart's gift to show the Taung child to these first notable visitors. Not only Dart but the University of the Witwatersrand (Wits) and the Witwatersrand Council of Education were under the impression that Dart owned the skull. This is confirmed by a passage in Dart's autobiographical Adventures with the Missing Link: "Perhaps, like Davidson Black [who had revealed Peking Man to the world], I should have travelled overseas with my specimens to evoke support for my beliefs, and I was presented with this opportunity. The Witwatersrand Council of Education wrote to say they appreciated that, because of the lack of comparative material in the form of anthropoid skulls of corresponding age, it would be impossible for me to perform a satisfactory monographic study of the Taungs [sic] skull in South Africa. The Council said they were willing to defray the expenses of my going to England for this study provided I donated the skull to the university. After careful thought, I decided I could not be bound by such a conditional undertaking [emphasis mine]”. [5, p. 51] When the Council of Education's offer had been refused by Dart, the Taung skull remained to all intents and purposes his personal property. This view persisted from 1925 to the end of 1958, when Dart relinquished the chair of anatomy to me. At that stage Dart told me that he was handing the custody of the Taung skull to myself. There was no written agreement and, to the best of my recollection, no mention of ownership of the skull. At Dart's behest, I was to be the guardian and keeper of the skull. Thus it has remained. Although I gladly accepted the responsibility of being custodian of the Taung skull, I have never considered that I was the owner of the skull. In terms of the policy set out below, the fossil is, in the broadest sense, owned by the world - as world treasure. In the narrower and more practical sense, the fossil belongs to South Africa, a viewpoint I have stressed over many years. Within South Africa, the direct

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custodianship of the skull would repose in an appropriately-equipped and expertly staffed institution, usually a university or a museum, the choice of which would normally depend on (a) historical factors and (b) the convenience of researchers in palaeo-anthropology. This is in keeping with worldwide practice, for example in France, Germany, the United Kingdom, the Czech Republic, Russia, Hungary, Italy, Spain, Indonesia, China, Australia, the Chad Ethiopia, Kenya, Tanzania, Malawi and South Africa. Under these considerations, the Taung skull appropriately reposes in the University of the Witwatersrand, the Florisbad cranium in the National Museum in Bloemfontein, the Swartkrans and Kromdraai hominid fossils in the Northern Flagship Institution (Transvaal Museum), Pretoria, the Makapansgat remains in the University of the Witwatersrand, the Hopefield skull in the Iziko Museum (South African Museum), Cape Town. It should be noted that the term repatriation applies to the return of a fossil or other object to the country of origin from another country to which it had been removed. It does not apply to the movement of fossils from one locality to another within the same country (see Conclusions). It could be argued that Dart's personal claim to ownership rested on his extraction of the skull from the breccia received by him, and on his recognition of the unprecedented complex of traits that pointed to the child's special place in hominid evolution. Dart had not excavated the specimen from the Buxton Limeworks: that had been carried out by a limeworker, M. de Bruyn, while, on the instructions of A.F. Campbell of Johannesburg, the box of specimens had been retained in the site office of the works manager, A.E. Spiers. Other links in the chain of discovery had been forged by E.G. Izod, "Pat" Izod, Miss Josephine Salmons and Professor Robert Burns Young. On a visit to Taung from the Wits geology department, Young had selected the fossil-bearing breccia blocks, including the one with the Taung child skull. Young had arranged for them to be brought to Johannesburg and handed over to Dart on 28th November 1924. In this chain of interlinking moments, Dart's role was the final and inevitably the most important one [22,23]. 2. Thomas Dreyer and Florisbad Dart's claim of ownership was not unique in those days. When the Florisbad cranium was discovered in 1932 by Professor T.F. Dreyer [6] near Bloemfontein in the Free State Province, the assistants who helped him in the excavation, A.J.D. Meiring and A.C. Hoffman, were not allowed to come near the Florisbad cranium. According to what Hoffman told me years later, Dreyer, overcome by emotion, hugged the cranium to his bosom, and threw clods at the two young men when they tried to approach to see the fossil! Dreyer's possessiveness and

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"ownership" of the cranium were evident from that point. Some twenty two years later, the annual conference of the South African Association for the Advancement of Science met at the National Museum in Bloemfontein under the presidentship of Hoffman, then Director of the Museum. Dreyer, aged and ill, came from his home to the Museum to show the participants the important Florisbad cranium. Earlier that year Dreyer had received a doctorate of science honoris causa from the Witwatersrand University. This recognition was for Dreyer a high-water mark, for he had long smarted under his perception that the Florisbad cranium had been spurned by Dart's school in Johannesburg and Drennan's in Cape Town. The culmination came with Dreyer's last public showing of the Florisbad skull at the National Museum. Soon after these two signal events, Dreyer died, doubtless a happier man than he had been in the decades of frustration and resentment. To this day Florisbad remains the most important fossil hominid find from the Free State Province. 3. Sergio Sergi and the Italian Neandertals Another example of claimed ownership was of the Italian fossils of San Felice Circeo (Monte Circeo) and Saccopastore. These splendid Neandertal skulls reposed in the Institute of Anthropology at the University of Rome under its Director, Professor Sergio Sergi (1878-1972). Sergi told me that during the German occupation of Italy in World War II, he became aware that German officers were seeking fossil treasures for Hitler and that they wished to obtain these skulls. Some of this story Sergi himself told me during my visit in the 1960s. Further details were kindly filled in by Professor Giorgio Manzi of Universita di Roma "La Sapienza", helped by Professor P. Passarello, and Professor A.G. Segre and Mme. Eugenia Segre-Naldini. In the period between July 1943 and June 1944, a German officer called on Sergio Sergi and asked to see these skulls. Sergi told the officer that the specimens were in Messina, Sicily, where his colleague Landogna was making special studies on them - or so said Sergi. He was well aware that the American forces had landed in Sicily, so that, even if the fossil skulls were there, access to them by Hitler's agents would have been impossible. In fact Sergi had instructed his technician, Maria Ricca, to take the skulls secretly in an unexceptional shopping basket to a well known church, Santa Maria della Pieta, in Trastevere, Rome, after a clandestine agreement with the clergy of that parish. The place of safe-keeping was below the altar of the church! At the end of the war, the crania of Saccopastore and San Felice Circeo were safely recovered and restored to the University of Rome. When S. Sergi retired from the directorship of the Institute of Anthropology, I was told by some Roman colleagues that he was not

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enamoured of his successor, Venerando Correnti. So Sergi removed the Saccopastore and San Felice Circeo skulls to his private apartment. In order to see the skulls, I had to seek an invitation to visit Sergi's apartment. The wizened octogenarian received me warmly when I arrived by appointment one morning. He had been studying hairs and had devised an apparatus (a "trichonophore") to hold an individual hair. With a "microtrichonometer", he had invented, he proceeded to measure the diameters of hairs. Another part of the extraordinary study was microtrichonoscopy! When I arrived for what I presumed would be a visit of at most a few hours (I had booked a city tour for the afternoon), Sergi started demonstrating these instruments to me, explaining how they worked and what he did with his results. The hours were passing...my city tour ticket was still in my pocket, a little hot and crumpled. I had not yet fulfilled the main purpose of my visit, to familiarise myself with the Italian fossil skulls. Then his daughter, also an anthropologist, whom it is said he had left "as his eyes and ears" in Correnti's Institute of Anthropology, announced that lunch was ready. Then another hour or two of microtrichonology ensued. In the late afternoon, Sergi was reminded that I wished to see those fossils. Into the bedroom we went, where they were kept in hat-boxes under the bed with one on top of the wardrobe. In a rather soporific state I examined these specimens. Sergi's rapid, soft, high-pitched pitter-patter of conversation provided background. By the time I took my leave at about eighteen hours in the evening, I was quite stupefied! It had been a memorable and unrepeatable experience. My unused city tour ticket was discarded. Those fossil skulls were Sergi's personal property (he believed); after all, had he not saved them from the looting of the German officers - and, for that matter, from the clutches of Correnti? On my visit to Correnti in the Institute, the poor plundered professor, whom I found a very pleasant person, insisted on telling me how he was burdened with the first name, Venerando ("Venerable!"). His grandfather had been a deeply pious man. He insisted that his grandson be given this name under pain of disinheritance. A little archly, Correnti said, “What could my parents do?” 4. Ralph Koenigswald and “Java man” A fourth palaeo-anthropologist who believed he owned the fossils for which he was responsible was Gustav Heinrich Ralph von Koenigswald. He had been responsible for discovering and recovering a number of fossils of "Java Man" along the Solo River, in what was then the Dutch East Indies, later Indonesia. Koenigswald later became a good friend of mine, from his first visit to South Africa in the early1950s soon after my appointment as a young lecturer in Dart's department. He had been born in Berlin in 1902 of Danish-German parentage.

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When he was only fourteen years of age, he and a friend made a first visit to Mauer near Heidelberg. Only ten years earlier, in 1907, a fossilised hominid mandible had been recovered from a quarry at the village of Mauer on the Elzenz River. In a letter to me, many years later, Koenigswald mentioned this visit: "I did not find a new Heidelberg Man, but a kind workman presented me with a molar of a rhinoceros, the first specimen of my vertebrate collection." Koenigswald accepted that he owned the rhinoceros tooth. Not long afterwards, Koenigswald visited Steinheim, 32 km north of Stuttgart in Wurttemberg. It was fifteen or sixteen years before Karl Sigrist jun. discovered the strange and interesting Homo cranium of Steinheim in his father's sand and gravel pit in 1933. On that early visit, Koenigswald recalled in a letter,"... the only mandible of a wolf ever found there I discovered, but left it to old Berckhemer, whom I have known since my school days." It was Fritz Berckhemer, who was later to excavate the famous Steinheim human cranium and to publish the first brief record of it in 1933. In both these instances, testified to by Koenigswald's correspondence with me, it is clear that from a tender age he held without question to the maxim, "finders keepers". It was "my vertebrate collection" and "I left it to old Berckhemer". The most crucial chapter in Koenigswald's career began in 1930. He accepted appointment to Java as a palaeontologist for the Netherlands Geological Survey. In January 1931 he landed at Tanjung Priok, the port of Jakarta. From 1931 to 1941 Koenigswald made some of the most important discoveries of Homo erectus specimens ever encountered and contributed appreciably to an understanding of their place in time and in hominid evolution. On two Javanese specimens, the Trinil calvaria that Eugene Dubois had recovered in 1891 and the Kedung Brubus mandible of 1890, I made re-studies that were published in 1966, 1967 and 1971. Here I dwell on the fate of the Javanese fossil hominids. In December 1941, Japan entered World War II. Within days, the famous original fossils of "Peking Man" had disappeared, while work in Java had come to a standstill. A last-minute American offer to move the original Javanese hominids to the United States was not accepted; in any event Koenigswald himself did not learn of the offer until after the war. He took extraordinary measures to ensure that "his" fossils were secreted and protected. Plaster casts were substituted for some of the original hominid fossils. In Koenigswald's words, The casts were extremely well made and to lay eyes almost indistinguishable from the originals. We had mixed finely ground brick dust with the plaster of Paris, so that even in the event of injury the break would remain nicely dark, as in a genuine fossil. We switched the skulls, so that if the

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contents of the safe should one day vanish eastwards a few original pieces, at least, would remain in the country." When the Japanese overran Java, Koenigswald was taken captive and he spent many months in a prisoner-of-war camp. However, his wife, Luitgarde von Koenigswald, whom he had married at Bandung in 1935, was allowed to stay out of the prison camp. The new Javanese fossil finds, some of which had not yet been described, were saved by her. In this operation, she was helped by neutral friends, namely two Swiss geologists from the Shell Company, Doctors Mohler and Rothpletz, and a Swedish journalist, Rulf Blomberg. The specimen that Koenigswald regarded as his most important discovery, namely the maxilla of Sangiran IV with its large palate and diastema (or space between the canine and first premolar), Mrs. von Koenigswald kept in her pocket throughout the Japanese occupation. Other specimens were concealed by Koenigwald's friends, the villagers and the neutrals. On one occasion, the Swedish friend, fearing a house search, put the entire collection of isolated teeth which he was safeguarding, into large empty milk bottles which he buried in his garden by night! Because of Koenigswald's foresight, all of the Javanese hominid fossils survived the war. It was a remarkable legacy to posterity and to the post-war flowering of science. His achievement stands in marked contrast to the tragic loss of the Peking Man remains. At the end of hostilities, a weakened Koenigswald was released and re-united with his family, Luitgarde, daughter Annamaria-Felicitas and all of "his specimens", save for one of the Solo skulls from Ngandong. Later, the missing Solo cranium was found by an American officer, Walter Fairservis, in the Household Museum of the Japanese Emperor. The skull was repatriated to its fellows in Koenigswald's hands. Franz Weidenreich had escaped from the Japanese occupying forces in China and got safely to New York. Following a letter Koenigswald sent to Weidenreich, the latter arranged with the Rockefeller Foundation and the Viking Fund (forerunner of the Wenner-Gren Foundation for Anthropological Research) to bring the Koenigswalds' live and fossil families to America. The Javanese fossils were in his perception his own: he had led the team that dug many of them up and he had saved them from wartime pillaging. When the Rijksuniversiteit of Utrecht in The Netherlands created a chair of stratigraphy and palaeontology especially for Koenigswald, off he went with his itinerant fossils for a twenty-years' sojourn in Utrecht. During these twenty years, highly productive ones from Koenigswald's point of view, he brought the Javanese fossils across to Cambridge, Engand, in 1964, where, as a visiting professor, I had the originals of the Leakeys' Tanzanian fossils. There followed an "Afro-Asian Conference - with a

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difference"! [24]. Once more, Koenigswald felt free to pack "his" fossils, and trundle them across the seas. At Utrecht, Koenigswald dreamed of establishing a great international centre for the cherishing and safeguarding of "his" Javanese hominid fossils and for the study of human evolution. His plans were not to be realised in The Netherlands. Instead, in Germany, the Wemer-Reimers Foundation provided facilities at the Senckenberg Research Institute and Natural History Museum of Frankfurt. Once again, Koenigswald packed his bags, his fossils and his personal library, and carried them off to Frankfurt, Germany. He still considered them his personal property. There is said to have been anger in The Netherlands when they learned that the birds had flown. In this case, they felt strongly: after all, the fossils had been discovered in Java when it was still a part of the Dutch East Indies; Koenigswald had been given a position in the Geological Survey and Dutch nationality; the University of Utrecht had created a new chair especially for him. Koenigswald spent the last fourteen years of his life with his beloved fossils in the Senckenberg. He retained warm and close links with the Indonesian investigators, Teuku Jacob, Sastrohamidjojo Sartono and Pieter Marks. Jacob received his PhD degree at Utrecht and Koenigswald gave the Indonesian scholars much help and encouragement, when they visited him at his Institute in the Senckenberg. The relationship culminated in Koenigswald's last visit to Java in 1976 to receive the honorary doctorate of science of the Gadjah Mada University of Yogyakarta. It was the first honorary degree to have been awarded by that University to a European. On one of my visits to Indonesia after Koenigswald's death in 1982, my good friend, Teuku Jacob, told me that Koenigswald had returned to him the fossil cranium of Mojokerto, a child calvaria from Perning in Java. Jacob had taken it back to Yogyakarta after the Nobel Symposium in Karlskoga in 1978. It was black and almost as round as a large cricket ball, but the face, jaws and teeth were not present. There was a small deficiency of bone in the region of bregma (where the frontal bone and the two parietal bones approximate one another). Previous workers had taken this gap to be an unclosed anterior fontanelle, and they inferred from this that the Mojokerto individual represented a baby or young child. I had carefully examined the area in question, both in Utrecht and at the Senckenberg, with magnification. It was clear to me that a piece of bone had been broken away in that area, but that the gap was not the usually unmistakeable anterior fontanelle. I re-examined the black "cricket ball" in Jacob's hands in Yogyakarta. Then he appealed to me: could he be sure that this was the actual fossil specimen? Mindful of the cunningly devised casts that

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Koenigswald had prepared in Java as the Japanese were getting nearer, Jacob asked: could this not be one of those casts in which brick dust had been mixed with plaster of Paris? I examined it, especially in the region of bregma, and I tested the weight in my hand. I could detect nothing that would disqualify it from being the original. To satisfy Jacob's doubts, the only manner by which it could be proven one way or the other, short of sectioning the specimen which nobody's conscience would allow, was to scan it, that is, to make a CT-scan (Computerised Tomographic Scan) of the specimen. This non-invasive method would leave the specimen intact. I left Teuku Jacob with that suggestion, although at that time neither he nor I knew of the appropriate apparatus anywhere in Indonesia. Japan,Singapore and Australia might prove to be the nearest countries where this sort of study could be done. In reply to my letter of 30th July 2004, seeking follow-up information on this, Teuku Jacob wrote on 26th August 2004. He told me that the skull he had doubted before was the original as he had proved by scanning in Jakarta, Paris, Toulouse and Tokyo. The semicircular canals of the inner ear could clearly be seen and, when the black colour in the foramen magnum was scratched away, the natural pumice filling the brain-case was clearly revealed. When on 20th November 1983 I delivered the memorial address in honour of Koenigswald, at a commemorative function in the Senckenberg Museum, Frankfurt, I ended with these words: "[Koenigswald's qualities] all add up to a celebrated man, an eminent scientist, a loyal friend, an unparagoned personality, companion of the heart." [23]. I wondered at the time whether I should have added to the formidable tally of attributes I listed - "staunchest upholder of the private ownership of fossils". I am glad I left it out because of what I have recently learnt from Teuku Jacob (see below). 5. Franz Weidenreich and "Peking Man" An interesting contrast may be cited. Weidenreich departed from China several months before the Japanese occupation of Beijing late in 1941 and with his wife went to live and work in New York. He was able to take with him casts of Peking Man and of most of the important later Javanese finds, of which he had obtained casts from Koenigswald, during their exchange of visits in 1937 and 1939. Sadly, from one point of view, Weidenreich left the originals of Peking Man behind in China. Those Peking Man fossils disappeared not long afterwards and have never been seen again. The Java Man, which Koenigswald guarded as if they were his own children, survived - although it must be admitted that they are probably the most well-travelled fossils ever! Circumstances did not permit

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the Peking Man fossils to be removed when it was still tolerably safe to do so. Koenigswald created his own circumstances! These two pieces of historical happenstance should not, of course, be taken as indirect support for the private ownership of fossils! 6. The attitude towards ownership today It may fairly be acknowledged that all fossil hominid specimens that are found today belong to, and belong in, the country in which they are found. The fossils from northern Kenya, which emanated from east and west of Lake Turkana, and the Tugen Hills to the south, are part of the national heritage, of Kenya. The Olduvai, Laetoli and Peninj fossils from northern Tanzania are unequivocally Tanzanian treasure. The fossil hominids of Bahr-el-Ghazal and Toros-Menalla in the Chad Republic belong to the Chad. The change came about with the attainment from the 1960s onwards of uhuru, independence, decolonisation. Earlier, fossils discovered in colonies and protectorates were automatically taken to the "home country". Kenyan fossils discovered before uhuru went to the Natural History Museum in London. The same was true of fossils like the Kabwe or Broken Hill remains from Zambia and the Singa cranium from Sudan. From Algeria, the hominid fossils of Ternifine, and from Morocco, those of Casablanca, Jebel Irgoud and Sidi Abderrahman, were taken to Paris where they reposed in either the Musee de I'Homme, the Museum National d'Histoire Naturelle or the Institut de Paleontologie Humaine. There were similar examples from Eyasi in Tanganyika (before World War II), which were taken to Germany; and from Palestine/Israel from which fossils were taken to London, Paris and the Peabody Museum, Harvard University. Although it may be thought of as a delicate and sensitive issue, it is important to consider the fate of fossil remains which were removed from the far-flung comers of empires, to various "homelands" - which of course were not homelands at all, when looked at from the standpoint of the fossil human populations! It is accepted today by almost all countries and by UNESCO that such specimens are part of the legacy of their respective territories of origin. The question should therefore be asked: is there any valid reason why this principle should not apply to parts of the heritage discovered when political circumstances were different, for example, before independence? To be consistent, the principle should surely apply retrospectively. From a practical point of view, there are difficulties when a collection of specimens reposes partly in the land of the find and partly in some other country. For example, a scholar who wishes to study the Mount Carmel Homo fossils from the Tabun and Skhul caves would have to travel from the Natural History Museum in London, to the Peabody Museum of Harvard University,

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Then, if casts of these fossils Cambridge, Massachusetts, to the Rockefeller Museum in Jerusalem. were desired, some were officially obtainable from the University Museum, University of Pennsylvania, Philadelphia. In contrast, the division of the Sterkfontein hominid fossils into two collections is less inconvenient: there are over six hundred specimens in the School of Anatomical Sciences at the University of the Witwatersrand Medical School, Johannesburg, and one or two hundred specimens in the Transvaal Museum of the Northern Flagship Institution, in Pretoria. The two institutions are about fifty kilometres apart. That division of the collection founded on historical factors is inconvenient but not a serious hardship for the earnest scholar. Moreover, casts of excellent quality can be obtained from both host institutions 7. Repatriation of hominid fossils Should there be wholesale repatriation of hominid fossils from their places of enforced exile to their cradle-lands? On grounds of principle, this would be the most ethical solution, other things being equal. However, are other things equal? Where we are contemplating the future of objects of such rarity and of such historical and archival world value, we have to ask whether conditions in the source-land are such as to provide adequate protection, security, curatorial skills and custodianship. In some countries, such facilities may not be available. This lack would demand help from a body like UNESCO, for the construction of suitable vaults, the provision and training of curators, and the development of a culture of cherishing, appreciating, admiring and valuing the objects in question 8. Repatriation to Asia 8.1. Java, Indonesia. The return by Koenigswald of the "black cricket ball", the calvaria of the Mojokerto child, to Teuku Jacob of Gadjah Mada University at Yogyakarta, has been mentioned. In a recent letter received by me from Indonesia's most eminent palaeoanthropologist, Professor Teuku Jacob, more light has been thrown on repatriations to Indonesia. When Teuku Jacob was hospitalised for a few days in Utrecht in 1967, Koenigswald promised that he would return the collection to Java. In an interview in the Frankfurter Algemeine Zeitung in 1974, Koenigswald indicated that he would return the collection to Indonesia. A year later Teuku Jacob carried the Ngandong skulls back to Java. In 1997, he picked up the Sambungmachan skull 3 which he wrote had been "smuggled away to New York". Another Homo erectus skull had been spirited away from Indonesia

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and allegedly offered for sale by an antique dealer in Switzerland! Sambungmachan 4, Jacob wrote, was back in Java - in Bandung. All told, according to Teuku Jacob, around two-thirds of the Indonesian H. erectus were now in Yogyakarta, Java. Other pre-war Indonesian hominid fossils were still in Leiden and Frankfurt. It is largely owing to the persistent efforts of Teuku Jacob and the understanding and co-operative attitude of the late Ralph von Koenigswald that this satisfactory outcome has been achieved. China - It is not part of my theme to discuss here the lamentable loss of the "Peking Man" fossils, that had been discovered at Zhoukoudian near Beijing (formerly Peking). They were casualties of the Sino-Japanese theatre of World War II and their disappearance has never been adequately explained. Despite strenuous efforts by Chinese and USA colleagues, the missing collection of Homo erectus pekinensis fossils has never come to light during the lapse of sixty years. Happily, palaeoanthropologists at the IVPP (Institute for Vertebrate Palaeontology and Palaeoanthropology) in Beijing have subsequently made a number of important discoveries of H. erectus and other hominids in China A small repatriation is worth mentioning. To the University of Uppsala in Sweden several teeth of "Peking Man" from Zhoukoudian, Locus A., had found their way in the 1920s. Otto Zdansky in 1923 sent to Uppsala a lower premolar and an upper molar; while Birger Bohlin produced in 1927 a lower molar. In 1978, during the course of a meeting in Sweden, I was delighted to find that the teeth had survived and were still present in Uppsala. In addition Birger Bohlin was alive as a professor emeritus of the Institute of Geology at the University of Uppsala. During a visit to Uppsala, old Professor Birge Bohlin showed us those Chinese teeth that had been excavated over half a century earlier. At an informal get-together of the symposiasts, in the presence of Bohlin, the organiser, LarsKonig Konigsson, and Carl Gustav Bernhard, the Secretary-General of the Royal Swedish Academy of Sciences, Richard Leakey challenged the Swedes to return those Zhoukoudian teeth to the Institute of Vertebrate Palaeontology and Palaeo-anthropology (IVPP) in Beijing. I was in full agreement with the sentiment, although the way in which it was sprung on the Swedish hosts on such a Linnaean bicentenary occasion struck me as inappropriate. The teeth were duly returned to China. This was not a case of specimens having been taken away before independence. The removal of these fossils went back to a period when foreigners had had very few scruples about what they did with specimens from far-off cradle-lands.

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9. The situation in Africa 9.1. South Africa Although it was one of the self-governing dominions of the British Commonwealth, South Africa was in the fortunate position that its early fossil hominids were not removed to England. This was true of the early finds of the first two decades of the Union of South Africa, such as the calvaria of Boskop (1913) and the skull of Taung (1924), and all the later discoveries. Soon after I took over the custodianship of the Taung, Makapansgat and post-1965 Sterkfontein hominid fossils in 1959,1 was approached by a representative of a leading US university who offered to buy one australopithecine tooth for a considerable sum of money! Robert Broom had sold a number of Karoo fossil reptiles to colleagues in the USA, but I was deeply conscious of the value of fossil hominids to South Africa and strong ethical considerations loomed large in my thinking. I had not a moment's hesitation in rejecting the American offer! A great number of archaeological and physical anthropological specimens had been removed from South Africa, especially to Europe, in the nineteenth century, but these examples of the plunder of recent human skeletons and cultural objects fall outside the scope of this article Like South Africa, Australia fell under the commonwealth dispensation. Hence fossil human skulls recovered there have remained in that country. 9.2. East Africa Sudan - A cranium from Singa on the Blue Nile was early removed to the Natural History Museum in London. It was studied there by Arthur Smith Woodward in 1938 [26], by Lawrence H. Wells in 1951 [25] and by me in 1955 [17]. In 1963, Don Brothwell was making a detailed re-study of the Singa skull. To the best of my knowledge, the cranium still reposes in the Natural History Museum, London. Kenya - A number of the earlier discoveries of Upper Pleistocene Homo specimens from Kenya still reposed in the Natural History Museum, London, when I last enquired. These included remains from Kanam and Kanjera, but not those found since the end of World War II, such as the Koobi Fora, West Turkana, Tugen Hills and Lake Baringo fossils. In Nairobi, Richard Leakey caused a fine facility to be built with generous support from the Royal Swedish Academy of Science and other international sources. In this were housed all of the fossil hominids from Kenya that had been recovered after uhuru. It was initially given the name TILLMIAP, The International Louis Leakey Memorial Institute for African Prehistory. At the opening ceremony, a statue of Louis

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Leakey standing at the entrance of TILLMIAP was unveiled. This was an example of a former colony which had risen admirably to the need for the bones of its earliest citizens to be housed in ideal conditions Tanzania - Two or three fossil partial crania were recovered by KohlLarsen from Lake Eyasi in northern Tanganyika (as it then was). When I studied these specimens, Eyasi II was represented by an occipital bone in the National Museum, Dar-es-Salaam. Its marked occipital torus was reminiscent of those of Kabwe, Zambia, and Hopefield, Western Cape Province. Eyasi I was still in Germany to which Kohl-Larsen had removed it. Clearly these Eyasi remains should be re-united in Tanzania, if this has not already been done. There is an interesting example of a successful local repatriation, where the fossil concerned was an "expatriate" for a short period. Mary Leakey discovered the magnificent cranium of Australopithecus boisei (called originally by Louis Leakey Zinjanthropus boisei, and nicknamed variously "Zinj", "Dear Boy" and "Nutcracker Man"). It was removed from Tanzania to the Leakeys' base at the National Museum in Nairobi, Kenya. I worked on it there and also in the Witwatersrand University Anatomy Department. When I had completed my study [19], Louis Leakey arranged for "Zinj" to be returned to the newly independent and re-named Tanzania. From the scientific academies of Beijing, Moscow, Paris, London and Washington, leading figures in palaeontology came to Dar-es-Salaam for the handing-over ceremony. I was invited to be present although it was stipulated that I attend not as a representative of any organisation or country, but as the person who had worked on the fossil for some five years! A special depository was constructed in the National Museum (formerly the George V Museum) in Dar-es-Salaam. This was made exceptionally secure, fire proof, with temperature- and humidity-control. It was a model of how the world's most precious fossils should be housed. President Julius Nyerere took a personal interest in the repository and played an active part in the ceremony that took place in the grounds of the Museum. Here was a National Museum that was convinced of the need to erect suitable facilities and, when funds were forthcoming, they did just that. 9.3. North Africa

Fossil hominids were originally removed from Algeria and Morocco to France. The most important specimens were: from Algeria - mandibles, teeth and a parietal bone from Temifine; from Morocco - specimens from Temara, Sidi Abderrahman, Rabat, Jebel Ighoud and Tangier (Mugharet-el-Aliya). From the Haua Fteah cave in Cyrenaica, Charles McBumey and a team from Cambridge University recovered two mandibles in a Levalloiso-

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Mousterian horizon. These were studied by J.C. Trevor and L.H. Wells (1953) and in greater detail by Tobias [20]. When last seen the two jaws were in the Natural History Museum, London. From the cave of Pore-Epic near Dire-Dawa in Ethiopia, a mandibular fragment was recovered. Its repository was last reported to be the Institut de Paleontologie Humaine, Paris. Chad Republic: - the cranium of Yayo (Koro Toro), discovered by Mme Francoise Coppens, was for many years in Paris where the author examined it jointly with Yves Coppens. Its latest repository was the Museum National d'Histoire Naturelle, Paris. The more recent Chadian finds from Bahr-el-Ghazal and Toros Menalla were recovered by a joint Franco-Chadian Expedition led by Michel Brunet of Poitiers, France. These specimens are housed in the Chad. 9.4. Central Africa The finest fossil hominid specimen to emerge, until today, from Zambia was the outstandingly complete cranium of what used to be called "Rhodesian Man" or Broken Hill Man. After independence it came to be known as Kabwe Man. This specimen was recovered by a miner, T. Zwigelaar, in 1921. From colonial Northern Rhodesia (later Zambia), the cranium went to the Natural History Museum, London. There, when I last looked, it still resided. It isunderstood that the Zambian Government had asked the British Museum to repatriate the skull to Zambia. This was earlier apparently declined by the British authorities, although I am uncertain of the grounds. It is one of the cases where an official, formal request for repatriation of a fossil hominid specimen has been made to a former colonial power by the fossil's source land. 10. Loss during repatriation This is the sad tale of "Egbert" the neandertal youth from Ksar 'Akil in the Lebanon. Father Franklin Ewing S.J. excavated in the cave deposit of Ksar 'Akil near Beirut in the Lebanon in 1938, and with his colleague J.G. Doherty, recovered human remains, described as "neandertaloid" in character. The best preserved was the partial skeleton of a child of about eight years old, to which Ewing gave the nickname "Egbert" because (he told me) of the state of preservation of its cranium - "like a broken eggshell!" Some other human remains were recovered. Egbert was for the time being in Fordham Catholic University in The Bronx, New York City, where I visited Ewing and "Egbert" in 1956. Father Ewing allowed me to handle and examine it. It included a good mandible and I obtained a cast of the cranium and mandible of the best specimen. I compared the Ksar 'Akil jaw with the juvenile jaw that McBurney

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had invited me to examine, from Haua Fteah in Cyrenaica. There were strong resemblances between the two mandibles and I included photographs of both in my description of the Haua Fteah remains, published in Charles McBumey's The Haua Fteah (Cyrenaica) and the Stone Age of the South-East Mediterranean (1967). In 1956 I took photographs of Ewing holding Egbert on the steps at the entrance to Fordham University. After Ewing's death, these remains were intended to be repatriated to Beirut. They were supposed to be sent from Fordham to the Society of Jesus' headquarters in Austria, with a view to their being returned to the museum in Lebanon, when circumstances permitted. The fossil bones have not been seen again, despite fairly rigorous enquiries made by Nancy Minugh-Purvis of Philadelphia and myself whilst a Visiting Professor at the University of Pennsylvania in the 1990s. So my 1956 photographs of Father Ewing and Egbert may be the last known photographs taken of the skull. 11. Le Moustier and Combe Capelle skeletons, problematical european repatriations The skeleton of Le Moustier Neandertal youth was brought to light in August 1908 in the Dordogne district in the south of France. The stone tools from this cave gave the name Mousterian to the associated archaeological industry [12] The skeleton was moved to Germany apparently without the enthusiastic acquiescence of French archaeologists. In Fossil Man, the 1923 English translation of the classical French work, Les Hommes Fossiles, by Marcellin Boule, a scathing account is given of the exhumation and removal of the Le Moustier skeleton. Essentially the same withering account is repeated in the 1957 English edition by Boule and Vallois: "In January 1909, a dealer in antiquities, of Swiss nationality, who had only too long exploited, for German profit, the deposits in the Dordogne district, that is to say, the most ancient and the most valuable archives in France, revealed the circumstances under which he had discovered and exhumed a human skeleton at Le Moustier The exhumation [by the Swiss dealer, O. Hauser] took place on the 10th August 1908, in the presence of a tribunal of scientists from beyond the Rhine- Klaatsch, H. Virchow, von den Steinen, Hahne, Wiist, and others (and, of course, in the absence of any French scientist). Even so the scientific value of this relic is markedly diminished by the poverty of significant stratigraphical or palaeontological data, and especially by the deplorable manner in which it was extricated and restored. The reconstruction of the skull by Klaatsch, a professor of anatomy, is a positive caricature...A second reconstruction, in which several of Klaatsch's distinguished colleagues were called upon to assist, has at least the merit of being more faithful. The monetary value of the skeleton from Le

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Moustier was, on the other hand, considered beyond compare by the 'Museum fur Volkerkunde' in Berlin, which paid Hauser, the dealer, the fabulous price of 125,000 [gold] francs!" In fairness to Hauser, however, when he brought the first limb-bones to light, he suspended operations for four months and entrusted the excavation of the bones to [11]. A year later, Otto Hauser recovered another skeleton, ornamented with sea shells, in a bed at Combe Capelle near Mont Ferrand in the Dordogne, France on 26th August 1909. This, too, was acquired by the Berlin Museum, Hauser once again acting as agent. Combe Capelle was considered to represent "a variety of the Cro- Magnon Race" [3] Then, for some thirty-five years, the two historical skeletons reposed in the State Museum in Berlin where they were rated as "two of the most important anthropological artefacts of the Museum fur Vor- und FrCihgeschichte" [10] During the Second World War, the bombing of Berlin onFebruary 1945 resulted in the Museum being hit. In the ensuing fire, the Le Moustier postcranial remains, among others, were severely damaged and partly destroyed. As a student I grew up with the teaching that Le Moustier skull had been lost, a casualty of the war. In 1957, Boule and Vallois wrote - not entirely accurately that the Le Moustier skeleton "was completely destroyed during the last war" (page 205, foot-note 22). In fact, the Le Moustier skull had been taken to the Soviet Union in 1945. Subsequently, the "lost" skull was located in Moscow, whence it was returned, along with the necklace of Combe Capelle, to the German Democratic Republic in 1958. For seven more years, the Le Moustier skull remained to all intents and purposes "lost" in Berlin. Only in 1965 was the skull "re-discovered" in Berlin where it was identified as that of Le Moustier [8,10]. Theoretically, if the Soviet authorities had known of the identity of the skulls, they would have been confronted with a dilemma: to which destination should the remains be returned - to France, from which they were removed almost a century ago, or to Berlin where, by purchase, they had reposed since about 1909? By today's thinking, the Le Moustier skull should have been sent to France. However, the Russians sent it back to the Berlin State Museum from which it had been plundered. This must be an unusual, if not unique, repatriation quandary, where there were two potential claimants for the "return" of a fossil Homo expatriate. However, if that was the theoretical position, it should be added that I have found no evidence that the skulls of Le Moustier and Combe Capelle were closely examined or identified specifically in Moscow. They were returned, along with stolen artworks in a packing case, to Berlin from which they had

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been taken. It was only in 1965 that Henrike Hesse "rediscovered" the Le Moustier skull [8]. In 1997, I was invited to Berlin by the German palaeo-anthropologist, Herbert Ullrich. He gave me the opportunity to examine the somewhat firescorched skull of Le Moustier and to confirm its identity. Until then, it had been one of very few European hominid fossils that I had not personally examined over the previous forty-five years. At the time of my visit to Berlin in 1997, the skull of Combe Capelle was still "missing". Strenuous efforts were made by German colleagues to find and identify the fragments of the calvaria, face and mandible. Isolated fragments had to be compared with illustrations and measurements that had been published much earlier [9] Only on 27th December 2001 could Almut Hoffmann and Dietrich Wegner announce that they had "re-discovered" and identified the skull of Combe Capelle without any doubt [10]. The cases of Le Moustier and Combe Capelle illustrate dramatically how, under wartime conditions, the purloining of fossils by invaders may add another dimension to the problems of expatriation and repatriation of fossil hominids. 12. Conclusions This article has been concerned, in the main, with case histories that illustrate claims for the ownership of hominid fossils. The coverage has not been universal, since I have confined my attention largely to examples with which I have been personally in contact. The article has dealt with specimens whose hominid status is not in doubt. There are a number of taxa whose systematic status is still uncertain; this includes fossils whose generic status has been variously assigned and at deeper, Miocene levels, whose classification as hominids has been proposed by some and opposed by other scholars. Examples of such indeterminate genera, or whose determinacy changes with the recovery of new specimens or alterations in the systematics of higher primates, are Otavipithecus, Kenyapithecus, Afropithecus, Samburupithecus, Nacholapithecus, Morotopithecus, Heliopithecus, Proconsul, Griphopithecus, Ankarapithecus, Oreopithecus, Rudapithecus, Graecopithecus, Sivapithecus, Lufengpithecus. It would be appropriate and judicious in the present context for specimens representative of such taxa to be handled, as though they were agreed hominids, at least until consensus was reached on their status. Therefore my conclusions below should be applied to such specimens. I staunchly support the idea that fossil hominids belong in and should remain in their country of origin. Where fossils have been removed to another country, they should be restored to their source-land. If there is doubt about whether the facilities in the cradle-land are adequate, the country of "adoption",

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perhaps helped by UNESCO, should offer to improve or help provide appropriate facilities for the permanent housing of the fossils in their cradleland. This category of heritage treasures comprises very rare specimens, most of which are unique. It would be valuable if UNESCO set up a commission to oversee problems of repatriation of fossil hominids, just as there is a special authority (the World Heritage Centre) to oversee sites and collections that have been placed on the World Heritage List. This analysis and these recommendations do not necessarily apply to recent human remains. A different set of issues may arise in such cases, especially if the bones in question are claimed by living peoples. Such claims may raise questions, on the credibility or authenticity of the claimed relationship between living populations and skeletal remains, especially where recent skeletal remains have been exhumed from unmarked and unidentified graves. It is less likely to apply to skeletons in anatomy departments of medical schools: under the law of South Africa, for instance, such skeletons may be prepared from bodies legally acquired from state institutions (such as hospitals), bodies, that is, of people who have died in such institutions unclaimed by relatives or bona fide friends. Another category of legally permissible acquisition of human bodies by medical schools is that of persons who have made testamentary provision for their bodies, after death, to be delivered to anatomy departments, or other medical school departments, of the institution chosen by the body donor. In respect of recent or lightly fossilised human material that has been removed from the country, such bones belong to the country of origin and should be repatriated to it. Would it be appropriate for such remains to be handed over to local populations who claim "ownership" of the remains? They might have reason to believe that the skulls or skeletons in question had originally been exhumed, or nefariously obtained, as by the unlawful killing of human beings, from people living in the "tribal" land or national territory, or who had belonged to the local population in question. There would however most commonly be problems of firmly establishing the provenance of such remains. Instead, I recommend that on repatriation such remains, should be returned to the state, which should be recognised as the appropriate authority to receive the remains. Taking what advice it needs, the state should determine the most suitable repository for them, be it in a university with a health sciences faculty, or in a museum. One other problem related to the main theme of this article has been raised by a colleague and has been under discussion in South Africa and elsewhere. This relates to requests received from time to time that specific fossils housed in museums or in universities be transferred to an authority close to the discovery site. The term 'repatriated' is clearly not applicable to such requests since

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'repatriate' means to return to the native land {Patria, native land). "Relocate" or even a borrowing of the genetical and botanical term "translocate', would be appropriate for a movement from one repository or locality to another within the country. Basically, the same essential principles should apply in such cases. The fossil in question belongs to the country within which it was discovered. Thus, the Taung skull belongs to South Africa and not to one of its areas or provinces. The second principle is that the specimen should repose in an appropriatelyequipped and expertly staffed institution. Thirdly, the choice of institution should depend on historical factors - by whom and where was the specimen recovered, extricated from the matrix or breccia, reconstructed and analysed? Fourthly, another important factor governing the choice of a suitable institution is this: the fossils, let it never be forgotten, are research materials. At which institution would the needs and convenience of researchers and graduate- and postgraduate students be best served? Regional interests and local tourism can be well served by the provision of superlatively made casts of selected fossil specimens. Experts at the repository should be willing to help design suitable displays and furnish reliable information for the erection of local exhibits at or near the source site. Successful examples of such local exhibits are those at Sterkfontein, South Africa; Olduvai Gorge, Tanzania, type site of Australopithecus boisei and Homo habilis; Zhoukoudian, near Beijing, the type site of Sinanthropus pekinensis, now known as Homo erectus pekinensis and still popularly called 'Peking Man'; and San Felice Circeo (Monte Circeo), the cave site on the west coast of peninsular Italy Acknowledgments My thanks are due to Teuku Jacob, Giorgio Manzi, Yves Coppens, P. Pasarello, Michel Brunet, Aldo G. Segre, Eugenia Segre-Naldini and earlier conversations and correspondence with Ralph von Koenigswald, Harry L. Shapiro, Louis, Mary and Richard Leakey, Desmond Clark, Birger Bohlin. I am grateful to Marion Bamford, Lucinda Backwell, Heather White and Peter Faugust. References 1. 2. 3.

Berckmer, F. 1933. Ein Menschen-Schadel aus den diluvialen Schottern von Steinheim a.d. Murr. Anthropologische Anzeiger 10, 318-321.M. Boule, M. 1923. Fossil Men: Elements of Human Palaeontology. Edinburgh, Oliver and Boyd. Boule, M. & Vallois, H.V. 1957. Fossil Men. New York, The Dryden Press

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Dart, R.A. 1925. Australopithecus africanus: the man-ape of South Africa. Nature, London 115, 195-199 Dart, R.A. & Craig, D. 1959. Adventures with the "Missing Link". New York, Harper and Brothers. Dreyer, T.F. 1935. A human skull from Florisbad, Orange Free State, with a note on the endocranial cast by Aliens Kappers. Koninklijke Akademie Van Wetenschappen in Amsterdam, Proceedings 38, 119-128. Dubois, E. 1891. Vooriopig bericht omtrent het onderzoek naar de Pleistocene en Tertiaire vertebraten-fauna van Sumatra en Java, gedurende het jaar 1890. Natuurkundig Tijdschrift voor Nederlandsch-lndie 51, 93-100 Hesse, H. & Ullrich, H. 1966. Schadel des "Homo mousteriensis Hauseri'! wiedergefunden. Biologische Rundschau 4,158-160 Hoffman, A. 1997. Zur Geschichte des Fundes von Le Moustier. Ada Praehistorica et Archaeologica 29, 7-16. Hoffman, A. & Wegner, D. 2002. Der Schadel von Combe Capelle. Anthropologische Anzeiger 60(4), 333-339. Klaatsch, H. 1923. The Evolution and Progress of Mankind. London, T. Fisher Unwin. Klaatsch, H. & Hauser, O. 1909. Homo mousteriensis Hauserr. Ein altdiluvialer Skelettfund im Departement Dordogne und seine Zugehongkeit zum!Neanderthaltypus. Archiv. fur Anthropologie N.F. 7, 287-297. Klaatsch, H. 1909. Preuves que t'Homme moustehensis Hauseriappartient au type de Neanderthal. In: L'Homme Prehistorique 7,10-16 Koenigswald, G.H.R. Von. 1956. Meeting Prehistoric Man. London, Thames & Hudson Kohl-Larsen, L. 1943. Aufden Spuren des Vormenschen. Band I und II. Stuttgart, Strecker und Schroder Leakey, LS.B. 1959. A new fossil skull from Olduvai. Nature, London 184, 491V. 493. Tobias, P.V. 1962. Early members of the genus Homo in Africa. In: Kurth, G., Ed., Evolution und Hominisation 191-204. Stuttgart, Gustav Fischer! Tobias, P.V. 1966. A re-examination of the Kedung Brubus mandible. Zoologische Mededelingen 41, 307-320. Tobias, P.V. 1967a. Olduvai Gorge - Vol. II. The Cranium and Maxillary Dentition of Australopithecus (Zinjanthropus) boisei. Cambridge, Cambridge University Press. Tobias, P.V. 1967b. The hominid skeletal remains of Haua Fteah. Appendix IB. In: McBumey, C.B.M. The Haua Fteah (Cyrenaica) and the Stone Age of the South-East Mediterranean, pp. 338-352. Cambridge, Cambridge University Press Tobias, P.V. 1971. The Brain in Hominid Evolution. New York and London, Columbia University Press Tobias, P.V. 1984a. Dart, Taungandthe 'Missing Link'. Johannesburg, University of the Witwatersrand Press for the Institute for the Study of Man in Africa.

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23. Tobias, P.V. 1984b. The life and work of Professor Dr. G.H.R. von Koenigswald. In: Auf den Spuren des Pithecanthropus. Leben und Werk von Prof. Dr. Gustav Heinrich Ralph von Koenigswald (1902-1982). Aufsatze und Reden der Senckenbergischen Naturforschenden Gesellschaft 34, 2596. 24. Tobias, P.V. & Koenigswald, G.H.R. Von 1964. A comparison between the Olduvai hominines and those of Java and some implications for hominid phylogeny. Nature, London 204, 515-518 25. Wells, LH. 1951. The fossil human skull from Singa. From Fossil Mammals of Africa, No. 2, London, British Museum of Natural History! 26. Woodward, A.S. 1938. A fossil skull of an ancestral Bushman from the Anglo-Egyptian Sudan. Antiquity 14,190-195.