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.     

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.     

Chemical Alteration and Use of Beeswax Through Time: Accelerated Ageing Tests and Analysis of Archaeological Samples from Various Environmental Contexts

In order better to interpret the chemical composition of ancient organic residues and artefacts containing beeswax, the degradation of this raw material was accelerated in the laboratory by controlled heating. During the course of degradation, deposits were condensed above the beeswax. Both degraded beeswax and these deposits were analysed. These experiments definitively proved that n‐alkane depletion is due to a sublimation process that depends on the molecular weight of these hydrocarbons. The formation of benzoic and cinnamic derivatives due to the degradation of flavonoid precursors initially present in beeswax has also been highlighted for the first time. The analysis of samples from Neolithic and Roman periods led to the identification of beeswax characterized by different degradation patterns linked to their environmental context.     

BYZANTINE OPAQUE RED GLASS TESSERAE FROM BEIT SHEAN,ISRAEL*

This paper presents the results of analysis of Byzantine opaque red glass tesserae derived from three separate locations in the ancient city of Beit Shean, Israel. Investigation proceeded using reflective light microscopy, energy dispersive X‐ray fluorescence and energy dispersive scanning electron microscopy. The glass matrix of the tesserae was found to be heterogeneous, with many inclusions. Similarities and differences between tesserae from the two mosaics are examined and discussed. Implications for locale of manufacture and production techniques are considered. Comparisons between the three locations led to conclusions about the use of the tunnel as a storage site and the implications of this for future research on mosaics.     

TECHNOLOGY AND PROVENANCE OF A COLLECTION OF ISLAMIC COPPER‐BASED OBJECTS AS FOUND BY CHEMICAL AND LEAD ISOTOPE ANALYSIS*

Chemical and lead isotope analyses were utilized to determine the composition, technology and origin of a collection of Islamic copper‐based objects found in Jordan. The atomic absorption spectrometry results show that the objects were made of different types of copper‐base alloys that contain various amounts of zinc, tin and lead. The use of brass, highly leaded brass and quaternary alloys of Cu‐Zn‐Sn‐Pb in the manufacture of everyday, household objects strongly points to Islamic traditions. The lead isotope compositions of the objects match very well that of the copper ore mined from the Dolomite‐Limestone‐Shale unit of the Arabah copper mines.     

NON‐DESTRUCTIVE PORTABLE GAMMA RAY SPECTROMETRY USED IN PROVENANCING ROMAN GRANITOID COLUMNS FROM LEPTIS MAGNA,NORTH AFRICA*

Portable gamma ray spectrometry (PGRS) provides a non destructive means to analyst quantitatively large artefacts, such as building stones, for the radioelements K. U and Th. Nine Raman granitoid columns at the Leptis Magna Ruins in Windsor Great Park, London, were measured in situ by PGRS. Corrections for the environmental background contribution to the gamma ray flux measured, and for the shape and size of the columns, are described Comparison of the PGRS data with a radioelement data base for Roman granite sources indicates that most of the columns originated in the Troad area of Turkey. Two columns could not be unambiguously provenanced using PGRS alone because there is insufficient difference between radioelement concentrations in certain sources. However, non‐destructive measurements of magnetic susceptibility, used in conjunction with PGRS data, suggest that these two columns originated in the Kozak Daǧ, also in Turkey.     

THE ORIGIN OF THE PICTORIAL KRATER FROM THE ‘MYCENAEAN’ TOMB AT TEL DAN

A Late Bronze Age Mycenaean pictorial krater, decorated with a chariot procession, from tomb 387 at Tel Dan, Israel, was examined by instrumental neutron activation analysis. The origin of the krater is placed in the Argolid, very likely in the region of Mycenae or Berbati.     

STATISTICAL EVALUATION OF THE PRESENTLY ACCUMULATED LEAD ISOTOPE DATA FROM ANATOLIA AND SURROUNDING REGIONS

Several hundred new stable lead isotope ratio determinations of ore and slag specimens from ancient mining sites throughout Anatolia and of samples of artefacts of the Chalcolithic, Bronze Age and Early Iron Age from museum collections in Turkey and the United States have been combined with the accumulated published isotope determinations of such specimens from throughout the eastern Mediterranean and Aegean regions to form a data base of nearly 1000 analyses. It is the purpose of this paper to evaluate the practical effectiveness of using this now extensive data base to discriminate between the many sources of metals throughout this region and to propose methods to enhance this discrimination. By using the full three-dimensional isotopic data in multivariate statistical treatments and by separating isotopically resolvable source groups within some of the source areas and isolating statistically outlying specimens from them, it has been possible to characterize some ore sources more precisely and compactly and thereby achieve better resolution between ore sources. It has also been possible to isolate isotopically compatible artefact groups which possibly relate to ore sources that, as yet, have not been well defined by isotopic analysis.     

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.     

GREENSTONE AXES FROM EASTERN CENTRAL SWEDEN: A TECHNOLOGICAL-PETROLOGICAL APPROACH*

Thin-section study of Mesolithic-Neolithic axes from five sites in eastern central Sweden and of dolerites occurring in the vicinity showed that the axes were almost definitely produced from local material. Knapping experiments were carried out on blanks from two of these local dolerite varieties and on control material from Delaware, New Jersey, to produce thin-butted axes. These showed that the unconventional shape of the Swedish preforms is mainly, if not completely, determined by the intrinsic properties of the rock and not by local or regional cultural differences or bad craftsmanship. A number of features were observed in thin-section, such as a relatively coarse grain size, veining and small cracks, which may lead to the inferior knapping qualities of the Swedish dolerites.