ACCESSORY MINERALS AS TRACERS IN THE PROVENANCING OF ARCHAEOLOGICAL MARBLES,USED IN COMBINATION WITH ISOTOPIC AND PETROGRAPHIC DATA*

Thirty‐eight archaeological marbles (Roman and medieval) from Modena and Reggio Emilia (northern Italy) were provenanced using the accessory minerals as tracers and the results were compared with those inferred for the same artefacts using isotope composition and MGS (maximum grain size of calcite grains). The number of inferred possible sources is generally lower when using the mineralogical method, which therefore seems to be suited to marble provenancing.     

MARBLE PROVENANCE INVESTIGATION OF ROMAN SARCOPHAGI FROM THESSALONIKI*

The provenance question of the marbles used for making the sarcophagi of local production of Thessaloniki in the Roman period had been posed by archaeologists in the past. The hypothesis was that the material came mainly from the quarries of Thassos Island. This paper presents the scientific analysis of 23 characteristic samples from selected sarcophagi at the Museum of Thessaloniki, using three different techniques: electron paramagnetic resonance (EPR) spectroscopy, stable isotope analysis and maximum grain size measurements, plus in-situ examination. New combinations of parameters were used in order to resolve fully the provenance of all samples. The results showed that the vast majority of the objects were indeed made in Thassian marble but from three different quarries, namely Vathy/Saliara (dolomitic marble), Aliki (calcitic marble) and Acropolis/Phanari (calcitic marble). The calcitic marbles from Aliki and to a lesser degree from Acropolis/Phanari are met in all the basic types of sarcophagi (framed type, plain type, garland sarcophagi). The use of the better quality and snow-white dolomitic marble from Vathy/Saliara quarries is relatively restricted and is often found in works that are above the average regarding the quality of their workmanship. In addition, two sarcophagi were made in Pentlelic marble and one in Proconnesian. The scientific analysis results provide a good confirmation of the archaeological estimates and, furthermore, the conclusions constitute henceforth a secure basis for the study of the entire sculptured works of Thessaloniki.     

DISCRIMINATING SOURCES OF MEDITERRANEAN MARBLES: A PATTERN RECOGNITION APPROACH

A computer-based pattern recognition procedure has been applied to trace element data obtained from marble samples of different Mediterranean quarries. Nineteen elements, mostly hydromagmatic and rare earth elements were first determined by neutron activation analysis. These elemental concentrations are then used as the data for further multivariate analysis. The results indicate significant differences in chemical patterns of the marble sources.     

Roman marble from Lusitania: petrographic and geochemical characterisation

This paper reports the results of an archaeometric study of the marble from the Estremoz Anticline, Portugal. Thirty-four samples from eleven different locations were analysed petrographically. In addition, ten samples were selected for trace element and strontium isotopic analysis. The sampling was aimed at obtaining material from known ancient quarries and at establishing the overall petrographic and geochemical variation of the marble from the Estremoz Anticline. The main type of marble in Estremoz is a white(-veined), calcitic marble with an average maximum grain size between 0.81 and 3.50 mm. ⁸⁷Sr/⁸⁶Sr values of marble leachates range from 0.70850 to 0.70891 and are similar to the results for other Palaeozoic marbles of the Iberian Peninsula.     

The White Marble of the Arch of Augustus (Susa,North‐Western Italy): Mineralogical and Petrographic Analysis for the Definition of its Origin

The Arch of Augustus in Susa (north‐western Italy) was built in 9–8 bc by King Cottius, to celebrate the treaty between the Romans and the Gauls. It is made of white marble, which was considered for a long time to be locally extracted, but no archaeometric studies have been performed up to now. Therefore, a multi‐analytical study based on petrographic (optical and scanning electron microscopy), electron microprobe and stable isotope analyses was carried out on the marble from the arch and from reference samples, with the aim of defining the provenance. All the data confirmed that white marble belonging to the metamorphosed carbonate cover of the Dora Maira Massif, known as Foresto marble, was used for the Susa Arch. This choice was probably made for economic reasons, but also due to the relative independence of the ruling family of the Alpes Cottiae, which was obviously interested in promoting a local marble.     

The use of white marbles for sculpture in Roman Gortyn (Crete) as revealed by archaeometric analyses

Gortyn was an important Cretan town from the late Archaic to the Hellenistic period and then became one of the provincial capitals of the Roman Empire. It controlled the whole of Crete and Cyrenaica and was a flourishing centre of trade and agricultural products in the first centuries of our era. In more than 100 years, many portions of the Greek and Roman town were unearthed under the supervision of the Italian Archaeological School of Athens and a considerable number of stone artefacts found, many of them made of imported marble since the local variety was grey and of poor quality. Statuary and other prestigious marble sculpted artefacts found in Gortyn were sampled and subjected to archaeometric examination (by way of optical microscopy in thin section, powder X-Ray diffraction and mass spectometry for the determination of the C and O isotopic ratio) in order to identify the quarries they came from. The results obtained from the analysis of several dozen white marble objects have indicated the use of a quite wide variety of species including Parian (from Lakkoi), Pentelic, Thasian (dolomitic and calcitic) and (occasionally) Proconnesian marbles. The first three, especially Pentelic, were used for most of the statuary.     

WHITE,VEINED MARBLE FROM ROMAN AMMAIA (PORTUGAL): PROVENANCE AND USE

A multimethod approach using petrography and strontium (Sr) isotopic analysis was applied to determine the geological source of 17 marble artefacts from the Roman town of Ammaia (Portugal). All samples are calcitic, with dolomite, quartz and muscovite as accessory minerals. The marbles are characteristically medium‐grained with a maximum grain size (MGS) between 0.98 mm and 1.82 mm, have a heteroblastic texture, and have curved to embayed calcite grain boundaries. ⁸⁷Sr/⁸⁶Sr values of marble leachates range from 0.708488 to 0.708639. Comparison with Hispanic and Mediterranean marbles suggests the Estremoz Anticline as the most likely source for the Ammaia marble, especially for architectural marble. This hypothesis is supported by the geographical proximity of the Estremoz marble district and the long and expensive overland transport required for other marbles to reach Ammaia.     

Non-destructive pXRF of mafic stone tools

Archaeological use of non-destructive pXRF has been most systematically applied to the classification and provenancing of volcanic glass (obsidian) artefacts. Comparable work has yet to be developed for non-vitreous artefacts. We report results of pXRF analysis for a sample of grey to black (mafic) aboriginal hatchets from Sydney and adjacent coastal regions to the north and south. The study shows both broad and detailed classification is achievable depending on rock type and degree of elemental depletion or enrichment of the samples. PXRF analysis reveals not only distinct patterns of resource use between the three regions of this study but also enables a high degree of geographic resolution in the case of the basalt artefacts of our sample. We conclude that non-destructive pXRF is effective for reliable characterisation of non-vitreous stone artefacts that have a sufficiently complex and enriched compositional signature (i.e., unaltered basalts); with ∼50% of the basalt hatchets in our sample matched with spatially and geologically specific sources.     

MILLSTONE PROVENANCING USED IN TRACING THE ROUTE OF A FOURTH-CENTURY BC GREEK MERCHANT SHIP

A Greek merchant ship carrying a cargo of millstones, amphorae and bronze vessels was wrecked at Sec, off Mallorca, Spain. in about 375-350 BC. Geochemical provenancing of the millstones helps in reconstructing the route of the ship and complements evidence from the amphorae. Thirty-eight lava hopper-rubber millstones and one Pompeian-style rotary mill from the ship were sampled for provenancing. The hopper-rubbers are mainly of basalt from the island of Pantelleria off North Africa in the Sicilian channel, one is from Nisyros off the Anatolian coast, and the Pompeian mill is of ignimbrite from Mulargia in Sardinia. The hopper-rubbers are the most westerly examples known in the Mediterranean. and the Nisyros mill represents the first proven instance of millstone transport between the east and the west Mediterranean. The occurrence of the Pompeian mill in a fourth-ceniury BC context is evidence of the use of this type a century earlier than previously thought. The Nisyros mill was probably taken on board at the start of the ship's voyage in the eastern Mediterranean, the Pantellerian mills may have been collected partly as ballast at Pantelleria, and the Mulargia mill was probably picked up at Carthage.     

APPLICATIONS OF PETROGRAPHY AND ELECTRON MICROPROBE ANALYSIS TO THE STUDY OF INDIAN STONE SCULPTURE*

Examples of research on ancient Indian stone artefacts utilizing petrographic examination coupled with qualitative and quantitative electron beam microprobe analysis of specific minerals are described. Types of artefacts discussed include Gandharan schist sculptures. Pala dynasty phyllite and schist objects from eastern India, Hoysala sculptures from Karnataka state (southern India), and sandstone objects from northern India. In spite of the rich history of stone sculpture in the Indian subcontinent, characterization studies to date have been limited in scope, typically involving unprovenanced artefacts. The examples described point to areas in which more extensive research could produce useful information for the provenancing of artefacts.     

THE ESTABLISHMENT OF A DATA BASE OF NEUTRON ACTIVATION ANALYSES OF WHITE MARBLE*

The establishment of a data base of trace element analysis results obtained by neutron activation analysis of 183 marble samples, each weighing about 200 mg, from eight different quarrying localities for use in provenance studies is described and a summary of the results presented. The problems of sampling museum artefacts are discussed, and details of tests of the reproducibility of the technique are given together with those obtained from multiple-samples from single museum objects. Replicate analyses of a marble standard are also discussed. Thus these data are a measure of the accuracy and precision of the technique, as well as allowing an assessment of the variation in trace element composition within quarry sources and single blocks of marble, as used for artefacts.     

The influence of different tempers on the composition of pottery

The modification of the raw clay by the potter to produce a paste suitable for the intended purposes adds a layer of obfuscation to the problem of provenancing the original clay source by chemical fingerprinting. By preparing different pastes from the same commercially available raw clay and their chemical analysis by Instrumental Neutron Activation Analysis, an experiment under controlled conditions (tempers, mixing ratios, firing temperatures and sampling methods) sheds light on the influence of different tempers.     

ISOTOPES ON THE BEACH,PART 2: NEODYMIUM ISOTOPIC ANALYSIS FOR THE PROVENANCING OF ROMAN GLASS‐MAKING

In this study, we have evaluated the applicability of Nd isotopic analysis for the provenancing of Roman glass and we present a database of Nd isotopic compositions of possible sand raw materials from the western Mediterranean, as a means of comparison for the growing number of isotopic studies on ancient glass. The ¹⁴³Nd/¹⁴⁴Nd isotope ratio of sands is a good indicator for their geological (and sometimes geographical) provenance. The use of the isotopic signature of Nd as a proxy for the source of silica in glass is, however, not always straightforward because of the possible overlap of signatures from different suppliers.     

SCIENTIFIC CHARACTERIZATION OF THE POHORJE MARBLES,SLOVENIA

As a former part of the great Roman Empire, Slovenia has many archaeological sites featuring buildings and objects entirely or partly constructed from marble whose provenance is doubtful. In Slovenia, the most probable source of such marble is the Pohorje Mountains. For the purpose of supporting further provenance studies, these marbles are fully scientifically characterized. The techniques used are petrographic and geochemical analysis, stable isotope ratio analysis and EPR spectroscopy. The results show that the Pohorje marbles are highly heterogeneous in both their isotopic and geochemical parameters as well as grain sizes. The parameters of the different Pohorje marble outcrops are compared between themselves and with the parameters of known ancient quarries in the Mediterranean and Austria. The use of a multi‐technique approach with combined parameters allows the best possible discrimination.     

X‐Ray Fluorescence and Stable Isotope Analysis of Marble in Central Lydia,Western Turkey

This paper presents the results of carbon and oxygen stable isotope analysis on marble quarries and artefacts from central Lydia, western Turkey under the auspices of the Central Lydia Archaeological Survey (CLAS). The marble survey and sampling programme studied 11 small‐scale quarries in the hinterland of the ancient city of Sardis. These quarries demonstrate evidence of ancient tool use, though their precise periods of operation were unknown prior to this study. The results presented here correlate material from these quarries with material previously studied from Sardis and from several tumuli in the monumental cemetery known as Bin Tepe. This study demonstrates that small quarries were important components of ancient social and economic landscapes, and that they are deserving of more consideration in archaeometric and marble studies. The data also point towards different social and economic factors at work in Lydian and Roman‐period marble acquisition.     

LASER ARGON DATING AND GEOLOGICAL PROVENANCING OF A STONE AXE FROM THE STONEHENGE ENVIRONS*

The recently-developed laser microprobe ⁴⁰argon-³⁹ argon technique has been used to give a geological date for a rhyolitic tuff stone axe fragment from the Stonehenge environs. The method requires only milligramme-sized samples and gives dates of sufficient accuracy to aid in provenancing artefacts to sources, as well as information on the heating history of samples. The axe sample is of Lower Carboniferous date (341 ± 5 Ma) and this limits possible sources to outcrops within the Scottish Midland Valley and small altered exposures in Dartmoor. X-ray fluorescence analysis of the axe suggests the Scottish Midland Valley as the more likely source. The laser argon analysis also shows that the implement had not been heated in antiquity. Laser argon-argon dating can, therefore, be a useful tool in artefact study.     

A SCULPTURAL MARBLE OF PRIME QUALITY IN ANTIQUITY—THE DOLOMITIC MARBLE OF THE SIVEC MOUNTAINS IN MACEDONIA

This paper presents analytical data on a major occurrence of fine‐grained dolomitic marble in the Sivec Mountains, close to the city of Prilep in today's former Yugoslavian Republic of Macedonia. This is the first presentation of an analytical database of a large‐scale source of fine‐grained dolomitic marble, whose ancient use can be demonstrated by tool marks and archaeological evidence. Many traces of ancient mining have fallen victim to a big modern quarrying operation in this area, which for decades has produced high‐quality blocks of marble (‘Macedonian Carrara’) and exported them all over the world. A combination of different analytical methods is used to characterize the marbles and to present a database for investigating ancient artefacts made of fine‐grained dolomites. Petrographic investigations revealed the very homogeneous micro‐fabric of this marble, which is of high purity with very low silicate contamination and has a maximum grain‐size of 1 mm. In addition to analysis of the stable isotopes, trace element analyses of carbonate lattice elements (Mg, Fe, Mn and Sr) were performed. An alternative method, the analysis of the chemical composition of the inclusion fluids, was also employed. On the basis of these techniques, a multivariate discrimination analysis was performed, and a clear separation of the different dolomitic marbles (Thasos, Ephesos, Proconnesos and Karacasu) was obtained. Finds of artefacts of high artistic quality made from this dolomite prove the existence of a significant workshop in the neighbourhood of the Sivec quarries. Because of its vulnerability to weathering, this fine‐grained dolomitic marble was used preferentially for indoor applications. Sculptures of prime artistic quality made of Sivec marble have so far been found in several locations of the Republic of Macedonia.     

ELECTRON SPIN RESONANCE STUDY OF WHITE MARBLES FROM THARROS (SARDINIA): A REAPPRAISAL OF THE TECHNIQUE,POSSIBILITIES AND LIMITATIONS*

The characterization of various samples of white marble from the archaeological site of Tharros (Sardinia) is the starting point for the reexamination of the capabilities of electron spin resonance (ESR) spectroscopy as a tool for identifying the quarries of origin of ancient marble artefacts. Existing methods and data bases are employed for the assignment of our samples, but also reviewed to see if a more extensive use of the technique is feasible. It turns out that ESR spectroscopy, coupled with other available methods, may readily provide valuable information, often yielding the final answer to the problem of marble provenance. However, it is also clear that much work has still to be done to standardize the data collection and analysis procedures and to expand the available data base.     

The Possibility of Provenancing A Series of Bronze Punic Coins Found At Tharros (Western Sardinia) Using the Literature Lead Isotope Database

A sample set of 42 bronze Punic coins dating from the third century bc and excavated in the Phoenician, Punic and then Roman town of Tharros (western Sardinia) has been used to test the performance of the literature lead isotope database and to establish a well defined provenancing procedure. A selection from the available database, including Cypriot, Sardinian and Spanish ore deposits, has been used. The complete assignment has been carried out twice, using both statistical methods (linear discriminant analysis) and the conventional raw data plots. Three major and one minor disagreements have been found, suggesting that the two procedures, when properly employed, may be acceptably compatible. Almost one third of the coins exhibit a characteristic Cypriot signature, whereas only very few samples are compatible with Sardinian ores. However, the majority of the coins (c. 60%) cannot be associated with any known source, which suggests the possibility of extensive metal recycling.