CHARACTERIZATION OF SAMIAN WARE SHERDS BY MEANS OF NEUTRON ACTIVATION ANALYSIS

Neutron activation analysis has been employed for the characterization of Samian ware sherds. The analysed samples were classified in ten groups, seven of which belonged to the Arretine production, according to archaeological evidence. By means of high resolution gamma-ray spectroscopy, 22 elements have been identified and analysed. Compositional characterization was looked for by taking counting rate ratios of different nuclides in the samples. The compositional pattern of the sherds was found to be fairly uniform both for each pot and for each group so that, at least in the examined cases, it can be assumed to be characteristic of a given workshop.     

THE APPLICATION OF INSTRUMENTAL NEUTRON ACTIVATION ANALYSIS TO A STUDY OF PREHISTORIC STEATITE ARTIFACTS AND SOURCE MATERIALS

A study of the trace and minor element content of steatite artifacts from the Eastern United States has been carried out. Samples from both quarry and habitation sites ranging from New York to North Carolina have been analyzed through the use of instrumental neutron activation analysis. The most successful method of evaluating data has involved the study of a very coherent group of elements known as the Rare Earths. Geological processes cause fractionation of this group and it is this fractionation which is of use in terms of characterizing the source deposits of this material. Promising but less definitive results have been obtained with the elements scandium, chromium, cobalt and others. Sufficient variations have been found to be present in the source deposits of steatite in this area to enable differentiation, and the successful linking of samples from habitation sites to their quarry deposits has been achieved in some cases. This paper discusses the results of this study to date, the methods employed, and the potential value of this work in helping to reconstruct prehistoric trading systems.     

NEUTRON ACTIVATION ANALYSIS OF ANCIENT BURMESE SILVER COINS WITH A LOW FLUX AMERICIUM/BERYLLIUM NEUTRON SOURCE

Nondestructive neutron activation analysis is by now a well-established technique for the analysis of ancient silver coins. The high activation cross-section of silver for thermal neutrons makes it possible to also use this method with the low neutron fluxes available from an isotopic neutron source. In this case due consideration must be given to minimize the self-shielding effect which is encountered with coins above a few tenths of a millimetre thickness. A simple method for the determination of the silver, copper and gold content in silver coins based on the self-shielding properties of silver alloys of different fineness is described. The method has been found to be useful for the quick routine assay of silver coins for the purpose of their classification. Seventeen ancient Burmese silver coins from three different cultural periods of Burma, and two British coins for comparison have been analyzed by this method.     

STEATITE SOURCE CHARACTERIZATION IN EASTERN NORTH AMERICA: NEW RESULTS USING INSTRUMENTAL NEUTRON ACTIVATION ANALYSIS*

Doubts have recently been cast on the ability to characterize steatite sources using rare earth elements (REEs). By increasing the number of samples and elements examined using instrumental neutron activation analysis (INAA) and multivariate statistics, this study shows that, with unhomogenized samples, transition metals, not REEs, make the greatest contribution in characterizing steatite sources in the Middle Atlantic region of eastern North America. Preliminary results suggest that INAA has the potential to assign provenance to steatite artefacts, at least at a regional level.     

NEUTRON ACTIVATION ANALYSIS OF FAIENCE BEADS

A selection of faience beads has been examined using neutron activation analysis, with a view to distinguishing the provenance of individual specimens. Evidence is presented that the tin content in beads from British sites is significantly higher than in those from other areas. Characteristic features of beads from other sources are also discussed.     

GEOMETRICAL FACTORS IN THE NEUTRON ACTIVATION ANALYSIS OF ARCHAEOLOGICAL SPECIMENS

In the neutron activation analysis of museum specimens, for which sampling is not permitted, corrections must be applied to measured activities to take into account the sample shape and its position relative to the detector. Correction factors are derived for samples of cylindrical shape such as segmented faience beads and a model technique is suggested for those of irregular shape such as flint and obsidian implements. These techniques used in gamma-ray spectrometry with lithium-drifted germanium detectors enable elemental concentrations to be determined from the measured count rates.     

NEUTRON ACTIVATION ANALYSIS OF PREHISTORIC FLINT MINE PRODUCTS

Specimens of flint from English and Continentai prehistoric factory/mine sites have been analysed using neutron activation and element compositions compared. The possible use of element concentration patterns as a means of characterising such sites is discussed.     

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.     

NEUTRON ACTIVATION ANALYSIS AT THE BRITISH MUSEUM,LONDON

Neutron activation analysis was used at the British Museum from 1978 until 2002 for provenance studies on ceramics and marble. Significant numbers of the items analysed were of high quality and value, and careful sampling was necessary to avoid damage to the object. An in‐house British Museum Standard Pottery was established and inter‐calibrated with a number of standards used by other archaeometry laboratories. The results of the projects have been published in many papers, and the databases established will be of use to future scholars interested in the ceramic groups represented. Projects on Greek and Near Eastern pottery have been undertaken. Relatively large numbers of north European medieval and post‐medieval pottery samples were analysed, as well as the tin‐glazed ceramics of Spain and Italy. Classical marble has also formed the subject of another project and a database of quarry material has been established.     

CORRECTIONS FOR DRILL-BIT CONTAMINATION IN SAMPLING ANCIENT POTTERY FOR NEUTRON ACTIVATION ANALYSIS

The routine measurement of tungsten concentrations in pottery sampled with tungsten-carbide drill bits has enabled the measured concentrations of cobalt, tantalum, and lutetium to be corrected for drill-bit contamination. The corrected data, for cobalt at least, are sufficiently accurate that they regain their value as chemical indicators of pottery provenance.     

COMPARISON OF NEUTRON ACTIVATION ANALYSIS FROM THE LAWRENCE BERKELEY LABORATORY AND THE HEBREW UNIVERSITY

Neutron activation measurements for Eu, Sc, Cs. Th, Ta, and Fe on 6 samples of pottery and rock by the Hebrew University and the Lawrence Berkeley Laboratory have been compared. The average disagreement exclusive of counting errors was 1.1%. The practical importance of this study to archaeology is that data taken on source materials in one laboratory can be used by the other. Methods of determining the consistency of measurements within a laboratory and sources oferrors are also discussed.     

ACKNOWLEDGING FIFTY YEARS OF NEUTRON ACTIVATION ANALYSIS IN ARCHAEOLOGY

Neutron activation analysis has been an important analytical technique for chemical characterization studies of archaeological materials since 1957, and remains one of the best analytical approaches for bulk chemical characterization of archaeological ceramics and other materials. This paper introduces a series of reports that document the history of NAA applied to archaeological materials.     

ANALYSIS OF COPPER-BASED METALLIC ARTIFACTS BY PROMPT GAMMA-RAY NEUTRON ACTIVATION ANALYSIS

Non-destructive analysis of the major elements in copper-alloyed artifacts by prompt gamma neutron activation analysis is reported. Copper, zinc, tin and lead were measured in several ancient Roman, Greek and Iranian objects. Good agreement was found in comparison with analysis of similar objects by destructive methods.