MEASURING CHRONOLOGICAL UNCERTAINTY IN INTENSIVE SURVEY FINDS: A CASE STUDY FROM ANTIKYTHERA,GREECE*

This paper considers how to make the most out of the rather imprecise chronological knowledge that we often have about the past. We focus here on the relative dating of artefacts during archaeological fieldwork, with particular emphasis on new ways to express and analyse chronological uncertainty. A probabilistic method for assigning artefacts to particular chronological periods is advocated and implemented for a large pottery data set from an intensive survey of the Greek island of Antikythera. We also highlight several statistical methods for exploring how uncertainty is shared amongst different periods in this data set and how these observed associations can prompt more sensitive interpretations of landscape‐scale patterns. The concluding discussion re‐emphasizes why these issues are relevant to wider methodological debates in archaeological field practice.     

Revisiting the Exploitable Threshold Model: 14th century resource procurement and landscape dynamics on Perry Mesa,Arizona

Abstract

This study presents a revision of Dean E. Arnold’s (1985, 1993) Exploitable Threshold Model, which attempts to explain the selection of raw materials for pottery production. Arnold’s model posits that potters’ preferences for materials are largely determined by the linear distance to individual resources. We argue, however, that potters’ choices are, at least in part, determined by spatial relationships among the necessary resources rather than the distances to them. This study of 14th century pottery production on Perry Mesa, Arizona demonstrates that potters selected materials based on the co-occurrence of readily available sources of temper, clay, and fuel. Lack of water and fuel sources on the mesa top compelled local residents to eschew the use of readily available basaltic sands to temper their plainware pottery. Instead, Perry Mesa potters selected granitic sands from the river valley nearly 300 vertical meters below their settlements.     

CHEMICAL–MINERALOGICAL ANALYSES AND MICROSTRUCTURAL STUDIES OF PREHISTORIC POTTERY FROM RAHMATABAD,SOUTH‐WEST IRAN*

A series of prehistoric pottery samples excavated from Rahmatabad, south‐west Iran, were investigated using XRF and XRD analyses to determine their chemical and mineralogical compositions. The sample microstructures were also studied by SEM/EDX. The relative similarity of compositions, the fine, dense and homogeneous microstructures and the presence of high‐temperature phases such as diopside and mullite showed the use of high firing temperatures, in the range 950–1050°C. This, along with the homogeneity in shape, decoration and size ranges of the ware, all indicate the adoption of specialized pottery‐making techniques by the potters of Rahmatabad in the fifth to fourth millennia bc .     

Post‐Depositional Elemental Alterations in Pottery: Neutron Activation Analyses of Surface and Core Samples*

From 38 sherds with ‘corroded’ surfaces, two samples per sherd were examined using Neutron Activation Analysis, one from the surface and one from the core of each sherd, in order to analyse post‐depositional alterations of minor and trace elements. The most striking effect was that a leaching of Ca could be found at the surface. Another group of elements that is severely affected are the alkali metals, with Cs and Rb showing the strongest changes. A third conspicuous group of elements are the Rare Earth Elements. Finally, the effect of such alterations on a statistical data evaluation to classify pottery according to provenance is investigated.     

Inductively coupled plasma emission spectroscopy and Postclassic Petén slipped pottery: an examination of pottery wares,social identity and trade*

ICP–ES analysis of the clay pastes of Postclassic (c. ad 850–1524) slipped pottery from the central Petén lakes region establishes chemical composition groups that provide information concerning manufacturing traditions and trading patterns. These data demonstrate that manufacturing traditions and trading patterns change throughout the Postclassic period, reflecting possible socio‐political alliances as different ethnic groups migrated to and from the Yucatán peninsula into the central Petén lakes region. The chemical composition groups also demonstrate that some manufacturing traditions imitate those from the Late Classic period and that some clay sources were used throughout the Postclassic period for multiple ceramic groups.     

INVESTIGATION ON ROMAN LEAD GLAZE FROM CANOSA: RESULTS OF CHEMICAL ANALYSES*

Five sherds of green glazed pottery excavated at Canosa (Apulia) in Italy have been analysed by scanning electron microscopy. The aim of the investigation was to determine the chemical composition of the glazes and thus obtain information on the methods used in their production. The glazes were all of the high‐lead type, coloured green by the addition of copper. Intermediate layers, observed at the interface between the glaze and body and giving the appearance of an applied white slip, were the result of the crystallization of lead feldspar from the molten glaze. Non‐calcareous clays were used in the production of the pottery bodies. Concentration profiles from the glaze exterior to the body suggested that the glazes were produced by applying a suspension consisting of lead oxide plus silica to the bodies. On the basis of the glaze and body compositions, it is suggested that the Canosa glazed pottery was produced locally.     

THE HISTORY OF THE LAWRENCE BERKELEY NATIONAL LABORATORY INSTRUMENTAL NEUTRON ACTIVATION ANALYSIS PROGRAMME FOR ARCHAEOLOGICAL AND GEOLOGICAL MATERIALS

The Lawrence Berkeley National Laboratory pottery provenance group developed standards and instrumental neutron activation analysis (INAA) methods that are used at many archaeometry laboratories around the world. The background and development of ‘Standard Pottery’ and of methods for INAA are described. Early pottery provenance studies are described, and other research programmes, involving obsidian and magmatic mixing, the origin of the stone used for the Colossi of Memnon, and the ‘Plate of Brass’, are mentioned. Research work by the Laboratory included the discovery of the world‐wide iridium anomaly and extensive subsequent research on what has come to be known as the ‘Asteroid Impact Theory’. Characteristics of the analytical programme for pottery provenance work, including overall aims, precision and accuracy, intercalibration, and irradiation and measurement protocols, are discussed. New research areas developed in the past 15 years, to broaden the usefulness of chemical compositional data for archaeological investigation, and examples of recent work, are described. This research, which makes use of high‐precision X‐ray fluorescence analysis in addition to INAA measurements on sample splits, includes distinguishing the products of different workshops located at the same production site, studies on the significance of the distribution of silver in archaeological pottery and the use of high‐precision chemical compositional data as an aid for making chronological distinctions.     

THE SMITHSONIAN–NIST PARTNERSHIP: THE APPLICATION OF INSTRUMENTAL NEUTRON ACTIVATION ANALYSIS TO ARCHAEOLOGY

The history and procedures of the Smithsonian–NIST programme in the application of instrumental neutron activation to the study of archaeological materials are reviewed. Statistical processing of the resulting analytical data is a major focus of the programme, with attention called to processes of initial group formation. Specific areas of current research emphasis are presented, which build upon the strength of accumulated databases.     

FOSSIL DIATOMS AND THEIR SIGNIFICANCE IN ARCHAEOLOGICAL RESEARCH

Summary. The relationship between environmental archaeology and diatom analysis, a well established technique in palaeoecology, is explored. The development of diatom analysis for palaeoenvironmental reconstruction is briefly considered and flow diagrams are presented to illustrate laboratory techniques. Examples of research in Mexico, North America, Britain and Europe are discussed to illustrate the potential of diatom analysis as a means of assessing human impact on the environment, notably lake water quality, and as a means of elucidating the palaeoenvironmental conditions under which archaeological sediments have accumulated. Consideration is also given to the role of diatom analysis in examining land/sea-level changes, especially those which may have affected prehistoric resource use, and to its significance in the reconstruction of local environments in and around archaeological sites. Finally, the potential of fossil diatoms for provenancing pottery is explored with particular reference to Dutch and Finnish examples.     

GC–MS ANALYSIS AND FATTY ACID RATIOS OF ARCHAEOLOGICAL POTSHERDS FROM THE WESTERN GREAT BASIN OF NORTH AMERICA*

The study of organic residues in archaeological pottery has focused on fatty acids due to their relative stability and longevity. However, even these compounds are subject to degradation, which makes assignment of residues to original foods problematic. This paper suggests that the use of ratios of fatty acids that degrade at roughly the same rate can be useful to identify very general categories of foods. It compares independent information on pot function based on ethnography and engineering/technological studies to that reconstructed based on extracted fatty acid ratios. The results support the notion that Great Basin pots were used primarily to boil seeds and that pot shape and pot function were related.