AN EPR AND ISOTOPIC STUDY OF THE MARBLES OF THE TRAJAN's ARCH AT ANCONA: AN EXAMPLE OF ALLEGED HYMETTIAN PROVENANCE*

The provenance of 20 marble samples drawn from the Trajan's arch at Ancona, which is supposed to be made of Greek, Hymettian marble, has been established on the basis of the independent use of EPR and isotopic data. The results of the two methods are in good agreement and unequivocally indicate a Proconnesian provenance. Sixteen samples are assigned to this site, whereas two are classified as untypical Proconnesian samples and the remaining two are assigned an unlikely Parian provenance. No indication exists for a possible Hymettian origin of the marbles. A multi‐method approach, which employs all of the experimental variables simultaneously, demonstrates that the 18 samples identified as Proconnesian belong to several different quarrying areas within the site. This result is taken as an indication that the Proconnesian quarries were run following a highly organized, semi‐industrial production model. The origin of the Hymettian/Proconnesian misunderstanding and the possible misclassification of other Roman monuments in Italy are briefly commented on.     

ON THE WHITE AND COLOURED MARBLES OF THE ROMAN TOWN OF CUICUL (DJEMILA,ALGERIA)

This paper reports the results of an archaeometric study of the local and imported marbles found in the Roman town of Cuicul (now Djemila, Algeria), a research project funded by the Sixth Framework Programme of the European Union. Of the few imported coloured lithotypes that have been found, four are of Greek origin and one was imported from Asia Minor. In addition, two other classical Roman coloured stones found on the site are probably of local North African origin (most likely one from Numidia and one from Algeria). With regard to the grey and white marbles employed in the statuary and architecture, petrographic study in thin section and the δ¹³C and δ¹⁸O isotopic data emphasize the frequent use of the local fine‐grained lithotype from Filfila (Skikda) together with imported Greek lithotypes (i.e., Pentelic marble, the dolomitic variety of Thasian marble, and Parian marble from Lakkoi) as well as different varieties of the so‐called ‘greco scritto’, whose provenance in some cases still remains uncertain. In fact, the petrographic and geochemical features of the marbles do not always match those known for the classical ‘greco scritto’ from the quarry of Cap de Garde, near Annaba (Algeria).     

PETROGRAPHIC AND ISOTOPIC CHARACTERIZATION OF THE MARBLE OF THE ISLAND OF TINOS (GREECE)*

Most outcrops of good‐quality crystalline marble in Mediterranean countries were exploited in Greek and Roman times. Hence, a wide variety of marble is now found in archaeological excavations. The precise determination of the provenance of a marble object is of great archaeological importance, and is now mostly obtained by coupling the petrographic study of a thin section with the analysis of the C and O stable isotopes, or by stereomicroscopy and EPR. The existing databases are considerable but still insufficient, because our knowledge about and study of ancient Mediterranean quarries remain incomplete. The contribution of this research is to add new petrographic and isotopic data on small quarries on the Greek island of Tinos that were exploited in antiquity. This marble belongs to the same geological horizon; it is quite pure, sometimes dolomitic and characterized by a low‐T, high‐P metamorphism that produced a limited recrystallization (MGS varying from 0.64 to 2.50 mm) on marine limestone protoliths. The petrographic features are quite distinctive: the fabric is strongly lineated and often stressed; and the accessory minerals are ubiquitary quartz, ore minerals, graphite and muscovite. As far as the isotopic data are concerned, δ¹³C_PDB varies from 1.1 to 2.7, and δ¹⁸O_PDB from ?1.7 to ?11.4. Both the features and the data have been compared with those of similar marbles used in antiquity, showing that their combination mirrors the fingerprint of the Tinos marble.     

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.     

Archaeometric analysis of the ‘greco scritto’ marble slabs from the Edificio dei Triclinii at Murecine (Pompeii,Italy)

This paper presents the results of the archaeometric analysis of the greco scritto marble slabs from the Edificio dei Triclinii, an inn or statio negotiatorum discovered at Murecine in Pompeii’s suburbs in 1999–2000. A total of 14 samples were collected and subjected to standard X-ray diffraction (XRD), optical microscopy (OM) on thin sections and stable isotope ratio analysis (SIRA) to assess the stone’s identity and provenance. The results of this study substantiate the hypothesis (already put forward and based on a macroscopic identification by Perna and Scognamiglio) that the stone originates from the Hasançavuşlar quarries near Ephesus in Asia Minor, and represent the first step towards a systematic contextual and geochemical study of Ephesian greco scritto in Roman contexts and its respective contribution to the Roman stone trade.     

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.     

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.     

Characterizing the Alabastro listato or fiorito of Hierapolis in Phrygia: A Simple Method to Identify its Provenance using Carbon Stable Isotopes

Alabastro listato or fiorito of Hierapolis in Phrygia was a prestigious coloured marble widely used in Roman architecture and decoration. This stone is generally identified in artefacts on autoptic examination, but it may sometimes be confused with alabasters of different provenances. This study describes a simple, but effective, scientific method to contribute to the determination of Hierapolis alabaster. Due to its unique genetic context, it is characterized by a distinctive carbon isotope signature. A comparison between the stable carbon isotope data from this paper and from the literature confirms the uniqueness of the isotopic character of Hierapolis alabaster. Carbon isotopes can ensure a reliably provenance attribution of the alabaster artefacts along with visual recognition by an expert eye.     

CARBON AND OXYGEN ISOTOPIC RATIOS: A DATA BASE FOR CLASSICAL GREEK AND ROMAN MARBLE

An isotopic data base of δ¹³C and δ¹⁸O analyses of 528 samples collected from 39 classical Greek and Roman quarries of Turkey, Greece, Italy and Tunisia has been accumulated. The discriminative possibilities of the data base vary from quarry to quarry. Most quarries have a distinctive pattern for either or both variables, but some have more than one grouping. The data also overlap for many quarries preventing a unique provenance assignment. If the alternatives are known so that the total pool of possible sources is reduced, the data base can then discriminate and assign a provenance for most classical marble artifacts.     

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.     

EPR OF Mn2+ IMPURITIES IN CALCITE: A DETAILED STUDY PERTINENT TO MARBLE PROVENANCE DETERMINATION*

We demonstrate that the electron paramagnetic resonance spectrum of Mn²⁺ impurities in calcite, and therefore also in marble, may be accurately reproduced by a traditional spin Hamiltonian formalism. The success of such a treatment, however, very much depends on the spin Hamiltonian parameters having the correct signs as well as magnitudes. We present data that determine the sign of the axial anisotropy parameter and thereby facilitate future quantum mechanical characterizations of marble electron paramagnetic resonance spectra that supplement provenance determination.     

A Multi‐Method Database of the Black and White Marbles of Göktepe (Aphrodisias), Including Isotopic,EPR, Trace and Petrographic Data

A database of the ancient marbles of Göktepe near Aphrodisias is reported, and includes 160 white, black and bichrome samples from 13 quarries and two waste deposits. The quarries are grouped into four districts. Districts 1 and 2, to the north, produced exclusively black or dark grey marbles (nero antico). Districts 3 and 4 produced white statuary marble. Nero antico and a black and white stone were also quarried in district 4, where the black marble surfaces again. The samples were characterized using petrography, isotopic analysis, EPR spectroscopy and trace analysis. The Göktepe white exhibits an unparalleled combination of fine grain, low EPR intensity and high strontium concentration that often allows easy identification. The isotopic values are less distinctive and similar to those for Carrara. In most cases, however, they are tightly grouped and also quite indicative. The black marbles exhibit a much weaker metamorphic overprint. With respect to the white marbles, they show analytical similarities but also notable differences. Therefore, establishing their provenance can be more difficult and may require the support of petrographic analysis. The results suggest that the Göktepe marbles were among the most prized and widespread statuary marbles used in Roman times, particularly from the early second century ad onwards.     

EVALUATION OF THE MANGANESE ESR METHOD OF MARBLE CHARACTERIZATION

Results suggest that ESR studies of Mn⁺² in marble can provide an excellent discriminator for the determination of marble provenance. In comparison with other methods of quantitative analysis for manganese such as AA or NAA, the ESR method determines only Mn⁺² rather than total Mn, is inexpensive and rapid with no chemical preparation required, and does not consume the sample.     

TRACING THE RESOURCES OF IRON WORKING AT ANCIENT SAGALASSOS (SOUTH‐WEST TURKEY): A COMBINED LEAD AND STRONTIUM ISOTOPE STUDY ON IRON ARTEFACTS AND ORES*

Lead and strontium isotope analyses were performed by thermal ionization mass spectrometry (TIMS) on Roman to Byzantine iron artefacts and iron ores from the territory of ancient Sagalassos (south‐west Turkey), to evaluate Pb and Sr isotopes for provenance determination of ores for local iron production. It can be demonstrated that for early Roman artefacts and hematite iron ore processed in early Roman times from Sagalassos proper, as well as for magnetite placer sands and early Byzantine raw iron from the territory of the city, Sr isotopes are much less ambiguous than Pb isotopes in providing clearly coherent signatures for ore and related iron objects. Late Roman iron objects were produced from iron ores that as yet remain unidentified. Early Byzantine iron artefacts display more scatter in both their Pb and Sr isotope signatures, indicating that many different ore sources may have been used. Our study demonstrates that iron objects can be precisely analysed for their Sr isotopic composition, which, compared to Pb isotopes, appears to be a much more powerful tool for distinguishing between chronological groups and determining the provenance of raw materials.     

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.     

Petrographic Characterization and Provenance Determination of the Crystalline Marbles Used in the Roman City of Banasa (Morocco): New Data on the Import of Iberian Marble in Roman North Africa

This paper reports the results of an archaeometric study of the crystalline marbles used in the Roman city of Banasa (Morocco). On‐site surveys allowed a detailed inspection of the monuments of the ancient city and sampling of the different marble lithotypes used for architectural purposes and sculptures. The inventory was completed by the study of both the grey‐and‐white streaked or spotted marble items stored in the warehouse of the archaeological site and of those currently exhibited at the National Archaeological Museum of Rabat. Provenance determination of 28 samples was carried out by means of a multi‐method approach combining mineralogical–petrographic data and C–O stable isotope analyses as the first step, and cathodoluminescence microscopy as a complementary technique to verify possible unusual alternative origins of some marbles. The analytical results obtained were compared with both the most reliable international databases and the few available studies dealing with the use of marble in other Roman towns in Morocco (e.g., Volubilis, Thamusida and Sala‐Chellah). They point to a variety of classical marble sources such as Carrara, Mount Penteli, Paros, Marmara and probably Mount Filfila (Algeria), and prove a significant import of Iberian lithotypes.     

AN INVESTIGATION OF THE PROVENANCE OF THE ROMAN AMPHORA CARGO FROM THE PLEMMIRIO B SHIPWRECK

Eighty-six Roman amphora sherds from the Plemmirio B shipwreck, off Sicily, have been analysed by neutron activation analysis. A large group representative of the amphora cargo, mainly of forms Africana 1 and Africana 2A (from the area of modern Tunisia), was subsequently defined. No differences between Africana 1 and Africana 2A samples were observed, thus implying a similar origin for both forms. The provenance of this cargo group was then investigated by comparison with a Roman amphora kiln data base. After elimination of the more mobile elements it was shown that the cargo amphorae were more likely to have been manufactured at kilns around Sullecthum rather than Leptis Minor. The analytical conclusions are thoroughly consistent with the known archaeological information.     

THE SUPPLY OF CAMPANIAN‐MADE SIGILLATA TO THE CITY OF POMPEII

Pompeii is an important temporal reference in the study of Roman ceramics, yet until now the origins of red slip tableware or sigillata found in the city have largely been classified by visual evaluations of the pottery. This investigation employs petrographic and elemental analyses to establish the provenance of sigillata found in two pre–ad 79 contexts of Pompeii. In contrast to previous studies, the results suggest that pottery workshops in the vicinity of Somma‐Vesuvius played a vital role in the supply of sigillata to the city.     

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.     

GEOCHEMICAL CHARACTERIZATION OF ARCHAEOLOGICAL LIME MORTARS: PROVENANCE INPUTS*

Chemical and mineralogical analyses were carried out on historical lime mortars from the parish church of Santa María La Real (Guipúzcoa). The study included various periods ranging from Roman to modern times and allowed the identification of various types of raw materials. In order to obtain pure binder, free of carbonate aggregates and charcoal particles, an innovative binder separation method was implemented. The chemical composition of the binder allows discrimination of different provenance areas for the raw materials, although those areas do not correlate with specific historical periods. In addition, the influence of burial processes on the primeval chemical features has been assessed and reveals that modern mortars display greater chemical modification than the Roman mortars.