FIXED‐FREQUENCY RADIO‐WAVE IMAGING OF SUBSURFACE ARCHAEOLOGICAL FEATURES: A MINIMALLY INVASIVE TECHNIQUE FOR STUDYING ARCHAEOLOGICAL SITES*

In memoriam Tony Clark Sadly, this research marked the last field visit to the test site that the authors were able to share with their colleague Tony Clark. His enthusiasm, experience and encouragement inspired us to complete this project that, to many, must have appeared as grown men at play in a sand pit. A new approach to subsurface exploration has been developed, based on fixed‐frequency radio‐wave illumination from a buried transmitter. Data are collected from a buried, continuous wave source with a phase‐coherent surface‐scanning receiver and recorded in a digital archive from which images of the archaeological features are subsequently produced. An important feature of this approach is the opportunity to separate the data collection and archive functions, which form an uncompromised record of the site, from the more subjective image formation function. This paper reports the results of a feasibility assessment programme and discusses the future application of the method to real archaeological sites.     

A SCIENTIFIC INVESTIGATION ON THE PROVENANCE AND TECHNOLOGY OF A BLACK‐FIGURE AMPHORA ATTRIBUTED TO THE PRIAM GROUP*

The restoration of a Greek black‐figure amphora provided an opportunity to study the provenance and production technology of the vase. The composition of the ceramic body, determined by inductively coupled plasma optical emission spectroscopy (ICP–OES), matches that of Attic products. Investigation by X‐ray diffraction and reflectance spectroscopy suggests a maximum firing temperature around 900°C and a body re‐oxidation temperature around 800°C, respectively. The morphology and composition of black, red and dark red surface areas were studied by scanning electron microscopy and X‐ray energy‐dispersive analysis; the black areas show the features of a typical well‐vitrified black gloss, while the red areas were most probably obtained by simple burnishing of the body; the dark red additions, on the other hand, are the likely result of a partial re‐oxidation of a clay–ochre mixture.     

FROM SUSA TO ANURADHAPURA: RECONSTRUCTING ASPECTS OF TRADE AND EXCHANGE IN BITUMEN‐COATED CERAMIC VESSELS BETWEEN IRAN AND SRI LANKA FROM THE THIRD TO THE NINTH CENTURIES AD*

In contrast with artefactual studies of long‐distance trade and exchange in South Asia during the Prehistoric and Early Historic periods ( Ardika et al. 1993 ; Gogte 1997 ; Krishnan and Coningham 1997 ; Tomber 2000 ; Gupta et al. 2001 ; Ford et al. 2005 ), few scientifically orientated analyses have focused on artefacts from the region's Historic period. During excavations at the ancient city of Anuradhapura, Sri Lanka, a number of buff ware ceramics with a putative organic coating on the interior were recovered ( Coningham 2006 ). Dated stylistically to between the third and ninth centuries ad , analysis of the coatings using gas chromatography–mass spectrometry (GC–MS) and stable isotope analysis (carbon and deuterium) confirmed that the coatings are bitumen—an organic product associated with petroleum deposits. There are no known bitumen sources in Sri Lanka, and biomarker distributions and isotopic signatures suggest that the majority of the samples appear to have come from a single bitumen source near Susa in Iran. The relationship between the bitumen coatings and the vessels is discussed, and it is suggested that the coatings were used to seal permeable ceramic containers to allow them to transport liquid commodities. This study enhances our knowledge of networks of trade and exchange between Sri Lanka and western Asia during Historic times.     

POST‐MEDIEVAL CRUCIBLE PRODUCTION AND DISTRIBUTION: A STUDY OF MATERIALS AND MATERIALITIES*

This paper is concerned with the manufacture and trade of post‐medieval crucibles (14th–19th centuries). The analytical study of crucibles from different contexts in Europe and America employed optical microscopy and SEM–EDS, coupled with archaeological and historical data. We identified two major producers of crucibles, both of them in Central Europe, whose products appear widely distributed internationally. The analytical data allow an explanation of the technical reasons behind their superior reputation, as both crucible types shared comparable material properties, such as thermal, chemical and mechanical stability. Conversely, the two crucible types were radically different in their manufacture and appearance. We argue that, besides technical considerations, sensorial aspects such as texture and colour may have played an important role in the perception and choice of materials.     

A MULTI‐ANALYTICAL APPROACH FOR THE CHARACTERIZATION OF COMMODITIES IN A CERAMIC JAR FROM ANTINOE (EGYPT)*

This paper describes a multi‐analytical chemical study performed on the original, almost totally conserved, content of a small ceramic jar from the Antinoe archaeological site (fifth to seventh centuries ad, Roman Egypt) and now belonging to the archaeological collection of the Istituto Papirologico ‘Girolamo Vitelli’ (Florence, Italy). Scanning electron microscopy with an energy‐dispersive X‐ray spectrometer (SEM–EDX), Fourier transformed infrared spectroscopy (FTIR) and X‐ray diffraction (XRD) were all used to characterize the inorganic components of the archaeological material. The organic substances were analysed using FTIR, direct exposure mass spectrometry (DE–MS) and gas chromatography – mass spectrometry (GC–MS). The inorganic component essentially consisted of halite (NaCl). Among the NaCl crystals, lamellar elements were identified. They were chemically characterized by carbonato‐apatite and showed a concentric morphology typical of the scales of small fish. The most prevalent organic constituents of the sample were monocarboxylic acids, α,ω‐dicarboxylic acids, and cholesterol and its oxidation products. The organic material composition was consistent with the occurrence of lipids of animal origin. In addition, diterpenes related to pine pitch were also identified. The overall results suggest that the material recovered in the small ceramic jar found in Antinoe is a residue of fish‐based pickles such as garum, muria, allex and liquamen, which were commonly used in Roman times.     

ON THE AGE AND CONTENT OF JAR‐35—A SEALED AND INTACT STORAGE JAR FOUND ON THE SOUTHERN PLATEAU OF QUMRAN*

An intact and sealed storage jar known as Jar‐35 was found in 2004, south of the Qumran settlement. A previous study identified tartrate in the deposit of the jar, indicating the possible past presence of wine ( Buti et al. 2006 ). However, we cannot confirm this finding. Using liquid and gas chromatography with mass spectrometric detection, no trace of tartaric acid or salts thereof could be detected in our samples. We show that the major component of the deposit is gypsum. No other organic compounds were identified with the methods that we have applied. Both radiocarbon dating of charcoal in the deposit and thermoluminescence dating of the ceramic jar show that it dates to the main period of habitation at Qumran (c. 100 bc to ad 70).