MECHANICAL PERFORMANCE OF QUARTZ-TEMPERED CERAMICS: PART II,HERTZIAN STRENGTH,WEAR RESISTANCE AND APPLICATIONS TO ANCIENT CERAMICS*

Mechanical performance of ceramics can be measured by various techniques. Conventional testing usually requires multiple samples of large size and specific geometries and for this reason cannot be usually applied directly to ancient pottery. However, Hertzian strength and wear resistance can be measured on the same specimen, of small size, and it is shown that these tests can describe, to a good approximation, the basic ceramic mechanical propertics (strength and toughness). Therefore, these tests are proposed for use on archaeological specimens. An application on Punic amphorae found in Corinth is presented.     

THE ENVIRONMENTAL STABILITY OF ANCIENT CERAMICS

A series of corrosion experiments was carried out using identical samples of a ceramic of known composition, structure and density which were subjected to a variety of simulated soil solutions. The action of the solutions was monitored by measuring their pH as a function of time at 25 °C and 90 °C. Under all conditions the pH stabilized rapidly. Microscopic and electron microscopic studies showed the presence of reaction/alteration products that would account for the observed pH changes. The findings indicate that ancient ceramics that exhibit no physical deterioration will have below their surface a composition corresponding to the composition of the sherd at the time of its burial.     

CALCAREOUS MICROFOSSILS IN BRONZE AGE AEGEAN CERAMICS: ILLUMINATING TECHNOLOGY AND PROVENANCE*

The calcareous skeletal remains of various microscopic organisms such as foraminifera and ostracods are a striking feature of thin sections of many archaeological ceramics from the Aegean Bronze Age. While the presence of these calcareous microfossils in pottery has been noted for some time, attempts to utilize them to further the aims of ceramic compositional analysis have been few in number. In the following paper, we take a first detailed look at the occurrence and utility of calcareous microfossils in archaeological ceramics. By presenting selected case studies from the Bronze Age of Crete, we demonstrate the potential of calcareous microfossils, especially the extremely small ‘nannofossils’ and the highly contextual geological information that they contain, in terms of the characterization and grouping of ceramics, the determination of their provenance and the reconstruction of ancient technology.     

ELECTRON PROBE MICROANALYSIS OF MIXED-ALKALI GLASSES

European mixed-alkali glasses are compared with Sayre and Smith's categorisation for ancient glass and with the chemical compositions of other prehistoric and later European glasses. The new categories reported here indicate that a wide range of alkali raw materials was used in the production of glasses found in prehistoric European contexts. At least five major chemical categories of glass are now known to have been used in prehistoric and early Roman Europe. A plant species of the genus Sulicorniu is suggested as a possible alkali source in ancient European glasses.     

RETENTION OF PHOSPHATE IN BURIED CERAMICS: AN ELECTRON MICROBEAM APPROACH

Elevated concentrations of P₂O₅ of 2–12 wt% absolute were observed in the matrices of a small group of ceramics with the electron microprobe. P₂O₅, CaO and FeO^t are enriched towards the surfaces in some cases and elemental correlations suggest precipitation of a crystalline calcium phosphate with a stoichiometry close to CaO · P₂O₅. Scanning electron microscopy with X-ray mapping showed P₂O₅ to be dispersed in the ceramic matrix on a very fine scale, while X-ray diffraction detected no crystalline phosphate. Parallels are drawn with the precipitation of phosphate in the surfaces of weathered glass. It is concluded that the amorphous phases produced on firing behave as chemically active substrates which facilitate the adsorption or precipitation of very fine grained calcium phosphate from the burial environment.     

PROVENANCE OF ANCIENT TEXTILES—A PILOT STUDY EVALUATING THE STRONTIUM ISOTOPE SYSTEM IN WOOL*

Strontium isotopes are used in archaeology to reconstruct human and animal migration routes. We present results of a pilot study applying strontium isotope analyses to modern sheep hair as a basis for its potential use as a provenance tracer for ancient woollen textiles. Our hydrofluoric acid‐based, lipid soluble analytical protocol, also tested on a number of ancient textile fibres, allows for contamination‐free, low blank strontium isotope analysis of minimal amounts of archaeological material. ⁸⁷Sr/⁸⁶Sr ratios of decontaminated sheep hair agree well with the compositions of biologically available (soluble) strontium fractions from the respective feeding ground soils, a translatable requirement for any potentially successful provenance tracing applied to wool textiles.     

A COMPARATIVE ELECTRON MICROPROBE STUDY OF LERNA III AND IV CERAMICS AND LOCAL CLAY-RICH SEDIMENTS*

This study uses electron microprobe analysis of ceramic artefacts and local day-rich sediments and lithics to help address questions concerning the nature of the cultural change implied by ceramics from Lerna III and IV. It redresses the previous lack of a comparative collection of clay-rich sediments that adequately represents the local variation in clay and temper for the area surrounding Lerna. The resulting comparisons indicate that although they produced stylistically different ceramics, potters from both Lenta phases acquired their clays from the local Lerna area.     

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.     

REGIONAL VARIATIONS IN TECHNOLOGICAL CHANGE AND IN POTENTIAL GAINS FROM CONSOLIDATION AMONG U.S. COMMERCIAL BANKS

ABSTRACT. This paper investigates the regional variations in the impact of technological change and in gains from consolidation among U.S. commercial banks. We estimate a multiproduct translog cost function with the appropriate regional dummy variables. Technological change, ray scale economies and scale biases in technological change are estimated for each region. Furthermore, pairwise expansion path economies between all the regions are calculated to evaluate the potential gains from interregional consolidation. In general Southwest banks had the worst and Southeast the best technological change. There is substantial disparity across regions. It also appears that technological change increased the efficient size in the Midwest and Southwest regions and reduced it in the West, Northeast and Southeast. Banks in all regions show ray economies of scale, affirming the need for larger banks if output mix remains constant. Finally, the results support takeover of regional banks by the Money Center banks but not vice-versa, and favor consolidation among regional banks. The biggest potential gains accrue from mergers of Southeast banks with either Midwest or Southwest banks and the least gains are derived from mergers between Midwest and Southwest banks.     

ELECTRON BACKSCATTER DIFFRACTION (EBSD): A NEW TECHNIQUE FOR THE IDENTIFICATION OF PIGMENTS AND RAW MATERIALS IN HISTORIC GLASSES AND CERAMICS

Coloured samples of glass and ceramic were selected for EBSD investigation to verify the potential (advantages and limitations) of this technique in the characterization of the raw materials used and the neoformation phases originating from the manufacturing processes. In the case of copper‐bearing red glasses, it was verified that micrometric droplets, residuals of the original copper source, can be ascribed to metallic copper or to a low‐Sn bronze, due to strongly similar lattice parameters. From the same samples, micrometric flakes were identified by EBSD as magnetite and interpreted as residues of the reducing agent used in the production of such red glasses. Further, the technique allowed the pigment responsible for the yellow colouring of some incised slipware to be recognized as bindheimite. In a third case, the black pigment, contained in some Nestorian decorated pottery, was identified as an amorphous phase of Mn oxide. The accurate identification of the colouring particles and other products or materials offered a more precise comprehension of the production technique, period and site of the examined artefacts, together with scientific parameters for the identification of the raw materials, their transformation during the production cycle and an evaluation of the most reliable recipes used for their preparation.     

ARCHAEOMAGNETIC DATING OF COPPER SMELTING SITE F2 IN THE TIMNA VALLEY (ISRAEL) AND ITS IMPLICATIONS FOR THE MODELLING OF ANCIENT TECHNOLOGICAL DEVELOPMENTS

Site F2 in the Timna Valley, Israel, is a small copper smelting site of ‘primitive’ technology, dated by its excavator to the Pottery Neolithic (sixth to fifth millennium bce ). This early date challenges the common view of the beginning of smelting technology in the Levant and has been contested by various scholars since its publication. In this study, we present results of archaeointensity experiments conducted on slag fragments from the site. The slag yielded an excellent ancient geomagnetic value (64.1 ± 1.1 μT) that, when compared to the Levantine master curve, suggests an age not older than the second millennium and most probably between the 13th and 11th centuries bce . In addition to demonstrating the applicability of geomagnetic archaeointensity experiments to independent dating of slag, we discuss the implications of the current results for the socio‐historical picture of the Timna Valley, and in particular for the way in which technological developments were previously modelled in the archaeometallurgical research on the region.     

PROVENANCE OF PUMICES IN THE NORTH COAST OF CYPRUS

With the aim of establishing the provenance of pumices along the North Coast of Cyprus, from Morphou to Kormakiti, chemical analysis, refractive indices determinations and mineralogical examination have been performed. On the basis of the experimental data the pumices can be distinguished into two groups. For the first one a provenance from Santorini can be established, for the second Yali, Kos and Milos can be taken into consideration as source localities.     

EVIDENCE FOR THE MIXING OF FATS AND WAXES IN ARCHAEOLOGICAL CERAMICS

Lipid residues from two Late Saxon/early medieval ceramic vessels recovered from excavations at West Cotton, Raunds, Northamptonshire, U.K., have been investigated by high-temperature gas chromatography (GC) and GC/mass spectrometry (GC/MS). The solvent extracts of sherds sampled from different points on each vessel (i.e., base, body and rim) were analysed quantitatively and qualitatively and compounds were identified which were characteristic of beeswax and animal fat. Furthermore, by determining the sites of accumulation of the specific lipid types and their concentrations in different parts of the vessels it can be inferred that the beeswax was added to the vessels prior to the addition of the fat. It was concluded that the two vessels performed different functions in antiquity.     

TOWARD A UNIFICATION OF CONCEPTS AND TERMS USED IN INTEGRAL LANDSCAPE INVESTIGATIONS

A discussion of the concepts and terms of landscape research developed and applied for more than a decade at the field stations of the Institute of Geography of Siberia and the Far East (Irkutsk). The key concepts are geosystems, which represent the sphere of interaction between animate and inanimate nature; ecosystems, which focus on the biotic aspect of geosystems. Geosystems are said to fall within the sphere of interest of the landscape geographer, while ecosystems are viewed as the study objects of ecology, a biological discipline. Although the two approaches are said to be distinctive, the interests of geographers and ecologists overlap, and a common terminology for both disciplines is proposed.