A QUANTITATIVE FABRIC ANALYSIS APPROACH TO THE DISCRIMINATION OF WHITE MARBLES*

Quantitative fabric analysis was applied in order to discriminate better among white marbles from various quarries of archaeological interest. This method provides an effective complementary tool to a characterization based upon petrography, cathodoluminescence microscopy and stable isotopes. Very good discrimination of marbles is achieved with the help of simple variables such as major axis and the shape-specific PARlS-factor. Using quantitative fabric analysis, marbles with similar cathodomicrofacies, as, for example, the Naxian quarries of Apiranthos, Koronos, Flerio and Kinidaros and the quarry of St. Beat (French Pyrenees), can be distinguished from each other. Marbles collected within one quarry may display dissimilar cathodomicrofacies. The common origin of such specimens can be determined with the aid of quantitative fabric analysis, as shown for the quarries of Kinidaros as well as St. Béat.     

AN UPDATED,MULTI‐METHOD DATABASE OF EPHESOS MARBLES,INCLUDING WHITE,GRECO SCRITTO AND BIGIO VARIETIES*

An updated database of Ephesos marbles including 244 samples from 16 quarrying districts is reported. The unknown Greco Scritto quarries near Hasançavuslar and the Bigio marbles from the quarries of Belevi and of Mt Panayir are also presented. The paper, however, is mostly devoted to the identification of the Ephesos white marbles, whereas the problems posed by the Bigio and Greco Scritto varieties are deferred to future work. The samples have been characterized by isotopic analysis, EPR spectroscopy and additional petrographic and optical properties. Owing to the complex geology of the region, the white marbles of Ephesos exhibit rather inhomogeneous properties and are conveniently classified into four marble groups, which can be almost completely discriminated. The problem of distinguishing the Ephesos white marbles from other similar varieties has been dealt with by statistically comparing the Ephesos samples with all the similar, medium‐grained varieties present in the marble database. Although some of the four Ephesos groups can be reliably identified, general solution of the discriminant problem is difficult. Historical archaeological information is needed to reduce the complexity of the problem by eliminating unlikely provenances. In this way relevant problems, such as the discrimination between Ephesos and Proconnesos marbles, can be solved.     

CARBON AND OXYGEN ISOTOPE RATIOS OF MARBLES FROM SOME ANCIENT QUARRIES OF WESTERN ANATOLIA AND THEIR ARCHAEOLOGICAL SIGNIFICANCE

¹³C/¹²C and ¹⁸O/¹⁶O ratios have been measured for 42 marbles from the main quarry localities of archaeological interest of Western Anatolia (Marmara, Ephesos, Aphrodisias, Denizli and Afyon) in order to test the possibility of isotopically characterizing ancient marbles from this region. The various groups of samples are not clearly distinguishable on a δ¹³C-δ¹⁸O diagram. However, if only white or slightly coloured samples are considered, the isotopic method appears to be much more selective.     

INVESTIGATION OF ELECTRON PARAMAGNETIC RESONANCE PEAKS IN SOME POWDERED GREEK WHITE MARBLES*

Within the context of white marble provenance research, 42 powdered white Greek marbles have been characterized using electron paramagnetic resonance (EPR) spectroscopy. Phase analysis was first carried out to separate calcitic and dolomitic marbles, then EPR spectra of Mnuc were studied. Investigation of other marble EPR spectra, especially around g — 2.00, led us to characterize five different signals. The intensities of Mn²⁺ lines permit the separatum of eight quarries into two groups, allowing a first discrimination, in the g = 2,00 region, only one signal has been found to be useful for provenance research objectives. The results are cheering and should lead to many other similar experiments.     

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.     

PROVENANCE OF MARBLES FROM NAXOS BASED ON MICROSTRUCTURAL AND GEOCHEMICAL CHARACTERIZATION

A detailed quantitative microstructural study coupled with cathodoluminescence and geochemical analyses on marbles from Naxos demonstrates that the analysis of microstructures is the most sensitive method to define the origin of marbles within, and between, different regions. Microstructure examination can only be used as an accurate provenance tool if a correction for the second‐phase content is considered. If second phases are not considered, a large spread of different microstructures occurs within sample sites, making a separation between neighbouring outcrops difficult or impossible. Moreover, this study shows that the origin of a marble is defined more precisely if the microstructural observations are coupled with cathodoluminescence data.     

Ancient ‘Black’ Decorative Stones and the Ephesian Origin of Sculptural bigio antico

Isotopic, EPR and petrographic studies aimed at establishing the provenance of sculptural bigio antico are reported, including 18 possible quarry sites and 21 ancient sculptures. The results demonstrate that the Belevi quarry, north‐east of Ephesos, above the more famous white marble quarry, was the major source of this marble. Nineteen artefacts belong to Belevi, whereas the precise origin of the remaining two is unknown, but must probably be found within the same area. The peculiar distribution of δ¹³C values both for Belevi and artefacts was crucial for inferring the correct provenance, subsequently confirmed by additional analytical and petrographic data.     

CATHODOLUMINESCENCE OF WHITE MARBLES: AN OVERVIEW*

Identifying the source area of white marbles has long been a problem in archaeology. To address this problem, about 1000 samples from known Classical quarrying areas in Greece, Italy and Turkey were analysed using cathodoluminescence. Twenty-one cathodomicrofacies were recognized, each of which generally characterizes a given area. In cases where the cathodomicrofacies is common to more than one area, δ¹³C and δ¹⁸O signatures provide an effective complementary dataset which allows additional distinctions. Determination keys for the 21 cathodomicrofacies observed are proposed based upon their principal cathodoluminescence colour, and their stable isotopic signature.     

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).     

New data of 87Sr/86Sr ratio in classical marble: an initial database for marble provenance determination

⁸⁷Sr/⁸⁶Sr ratios are presented for white marbles collected from some of the most famous classical quarry areas of the Mediterranean: Carrara, Paros, Naxos, Pentelikon, Dokimeion, Hymettus, Thasos, and Proconnesus. These ratios range from 0.7071 to 0.7092. The ranges of the different quarry areas are notably superimposed; this prevents a common adoption of this parameter in distinguishing the quarry locations for the classification of the provenance of marbles used during classical times for architectural and sculptural artefacts. However some quarry areas show peculiar distributions of their isotopic values, which could help to assign the provenance to an unknown marble artefact.Adding these new data to the scarce number of strontium isotopic compositions measured on white marbles and available in the relevant literature, permits the creation of an initial database of 11 classical quarry locations. This database confirms that the strontium isotope ratio could be used in marble provenance determination, together with petrographic and geochemical methods, as an ancillary technique.     

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.     

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.     

MULTI‐METHOD MARBLE PROVENANCE DETERMINATIONS: THE CARRARA MARBLES AS A CASE STUDY FOR THE COMBINED USE OF ISOTOPIC,ELECTRON SPIN RESONANCE AND PETROGRAPHIC DATA*

A multi‐method approach, based on petrography, stable isotope data and electron spin resonance spectroscopy for assigning the provenance of white marbles, is presented. A total of 11 experimental variables has been used, including the quantitative measurement of the sample colour and its homogeneity. On this basis we attempt to distinguish the three main quarrying basins of the Carrara district, that is, Torano, Miseglia and Colonnata. Such discrimination, extremely uncertain on the basis of the single techniques, may be performed with acceptable confidence’ using a properly selected subset of six petrographic, isotopic and spectroscopic variables. The final resubstitution and jackknifed re‐assignment rates are, respectively, 85% and 81%. Inclusion of the remaining five variables into the classification rule does not improve the results, but simply increases data overinterpretation. The practical possibility of using such an approach for more general provenancing problems is considered.     

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.     

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 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.     

Ionoluminescence and Cathodoluminescence in Marbles of Historic and Architectural Interest

Ion beam induced luminescence (IBIL) was applied, along with cathodoluminescence (CL), on seven samples of marbles of historic and architectural interest. The CL colours, observed in a cold cathode device, have been related to the IBIL spectra. Moreover, a detailed analysis of the IBIL spectral features has made it possible to disclose the influence of the chemical composition and to emphasize the crystal‐chemical role of the Mn²⁺. Beyond the chemical information and the crystal‐chemical interpretation, the spectra are recognized as being valuable in the field of archaeological studies for their significance as fingerprints of marbles, giving information on their nature and origin.     

PROVENANCE STUDY OF MARBLE ARTEFACTS FROM THE ROMAN BURIAL AREA OF FASCHENDORF (CARINTHIA,AUSTRIA)*

Numerous marble artefacts were among the extraordinary findings excavated at the Roman burial area of Faschendorf (Carinthia, Austria). The provenance of marble objects, particularly in the Roman provinces, is mostly unclear. Predominantly Mediterranean marbles have been used, but there are also some marble occurrences in the eastern Alpine regions that were exploited in those times. Besides a mineralogical–petrographic analysis, grain‐size evaluation in particular, and the determination of carbon and oxygen isotopes allow an effective characterization of the Faschendorf materials. Their provenance from the Gummern Marble complex in Carinthia is very likely.     

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.