Authors:R. Bugoi, V. Cojocaru, B. Constantinescu, F. Constantin, D. Grambole, and F. Herrmann
Several fragments of ancient gold objects coming from an Eneolithic hoard and from Pietroasa Cloca cu Puii de Aur (The Golden Brood Hen with Its Chickens) hoard, unearthed on Romanian territory, and two Romanian native gold nuggets samples were analyzed using micro-PIXE technique. The purpose of the study was to clarify the metal provenance. Trace and minor elements (Cu, Te, Sn, Pb, Ti, Cr, V, Mn, Ta) and platinum group elements (PGE) concentrations were estimated. The presence of inclusions (micrometer size areas of composition different from the surroundings) was investigated. We found Si and Ca inclusions on two Eneolithic samples, and Ta inclusions on two samples from Pietroasa hoard. The measurements suggested an alluvial origin of gold for the Eneolithic samples and give indications for the possible gold ore sources of Pietroasa hoard.
Neutron activation analysis was used for provenance studies of ceramics from the early middle ages (avar period). 14 trace elements and Fe were determined by multiisotope comparator method. Computerized mathematical statistical methods (cluster-, and similarity analysis) were used for grouping the samples according to the similarity of their trace element distributions.
Some theoretical aspects and limitations of XRF are discussed, including information depths in layered materials, characterization of inhomogeneous specimens, light element analysis, and radiation damage. Worked examples of applications of XRF and XRD are pigment analysis in delicate Chinese Paper, corrosion of glass, and leaching effects in soil-buried medieval coins.
Authors:M. Glascock, H. Neff, K. Stryker, and T. Johnson
An abbreviated NAA procedure has been developed to fingerprint obsidian artifacts in the Mesoamerican region. Despite the large number of available sources, an NAA procedure, which relies on producing short-lived isotopes, has been applied with a success rate greater than 90 percent. The abbreviated NAA procedure is rapid and cost competitive with the XRF technique more often applied in obsidian sourcing. Results from the analysis of over 1,200 obsidian artifacts from throughout Mesoamerica are presented.
Authors:F. Carrot, C. Dardenne, N. Deschamps, Ch. Lahanier, and G. Revel
In order to obtain sufficiently accurate results for the provenance characterization of ceramic objects, the error risks are studies at each step of the instrumental neutron activatin analysis. The homogeneity of clay figurines and the reproductibility of the analytical process are tested. For the sampling, a weight of 100 mg is enough to obtain significant results. The use of the K0 Standardization Method and a well specified position during the radioactive measurements, improve the precision of the element determinations. The experimental conditions chosen are described and the accuracy of the method is tested on international standards.
Red thermoluminescence (RTL) using a SAR (single-aliquot regenerative-dose) method has been applied to artificial ceramic samples to determine retrospective doses, and to estimate the naturally accumulated doses for natural quartz grains. In the RTL measurement of quartz grains, several preheating effects on equivalent doses around 200 °C were examined for extracted quartz grains from tephra (Medeshima, Miyagi). Preheating at 200 °C for 10 seconds gave better reproducibility and response than those for preheating at 80 °C for 5 minutes. The RTL/SAR method was used to quartz grain samples extracted from pottery pieces with preheating at 200 °C for 10 seconds.
Authors:K. Sueki, Y. Oura, W. Sato, H. Nakahara, and T. Tomizawa
Nondestructive determination of major and trace elements within voluminous materials has been demonstrated by prompt γ-ray
neutron activation analysis. Some fragmented pieces of pottery bowls considered to have been produced in the late 18th century
were analyzed by a new internal monostandard method, and noticeable differences of the elemental contents and significant
correlations of the elemental distributions were observed among the samples. The possibility of identification of producing
areas of unearthened material is demonstrated by the analytical results and the applicability of this method to the investigation
of precious samples in a completely nondestructive way is verified in practice.