Provenance of prehistoric obsidian artefacts from Kul Tepe,northwestern Iran using X-ray fluorescence (XRF) analysis

Analysis by X-ray fluorescence of 53 obsidian artifacts the main source of obsidian for the workshops in Kul Tepe was Syunik but obsidian sources as far as west as the Lake Van region (Nemrut Da? and Meydan Da?) and as far north as Gutansar were also utilized. These new results indicate a broad network of trade and exchange.     

Early Olmec obsidian trade and economic organization at San Lorenzo

The Olmec were the first complex society to develop in Mesoamerica between 1800 and 600 cal B.C. The earliest large Olmec center during this period was the archaeological site of San Lorenzo which emerged as Mesoamerica's first large ritual and political center between 1400 and 1000 cal B.C. San Lorenzo's growth as a prominent center included the development of long distance trade relationships with adjacent areas of Guatemala and highland Mexico. High precision chemical analysis of obsidian imported for use in the fabrication of cutting tools is used to reconstruct the growth, size and extent of San Lorenzo's interregional exchange networks with areas of Mexico and Guatemala where obsidian occurs as raw material. A total of 852 obsidian artifacts were analyzed to reconstruct changes in obsidian procurement between 1800 and 800 cal B.C. This represents one of the largest samples of sourced obsidian from a Mesoamerican site and it provides a comprehensive picture for the development of interregional trade networks for Mesoamerica's first large Olmec center.     

X荧光成分分析实验对测量陶瓷器热释光年代的影响研究

为了考察对一件已经经过X荧光分析实验的陶瓷样品进行热释光年代测定时,年代结果是否会受到X荧光分析实验的影响及其影响程度,本工作选取了古代与现代的陶器、瓷器及三彩样品共26件,在常规、经过胎体成分分析、经过釉层成分分析三种实验条件下测量比较热释光年代的变化.研究发现,对不同时代不同类型的样品,X荧光成分分析实验对热释光测年的影响程度不同;对部分样品的测年结果无影响,对部分样品的年代有增大的影响,但增大的程度不会使热释光测年结果产生真假颠倒的结论.     

油画保护性修复与清代马口铁底板的“美国货船油画”清洗修复研究

油画保护性修复是基于对绘画材料属性研究与修复保护的一种科学阐释。为了对中国古代油画进行科学的保护和修复,以清代一件"美国货船油画"为研究对象,围绕项目检测和修复方案制定展开深入研究。采用X射线荧光光谱仪、数码显微镜、紫外荧光等仪器并结合化学试剂测试对清代外销油画结构与画面表层污渍及棕色斑点进行分析。检测结果表明,棕色斑点中铁含量较高,应为铁锈。在保护修复中,应针对画面中锈斑进行清洗修复。     

A STUDY OF OBSIDIAN SOURCE USAGE IN THE CENTRAL ANDES OF ARGENTINA AND CHILE

We present the results of XRF analysis for 428 obsidian samples from archaeological sites in the Argentinian province of Mendoza and from central Chile. The archaeological samples come from different environments and have dates that range from 9000 to 300 bp . The results indicate that all known sources were utilized; however, the beginnings and the intensities of their exploitation were variable. On the contrary, strong differences appear, especially between the Cordilleran and the non‐Cordillera sources. We suggest that this pattern is mainly related to differences in the accessibility, quality and abundance of the obsidian in the sources.     

VARIETIES AND SOURCES OF ARTEFACTUAL OBSIDIAN IN THE MIDDLE STONE AGE OF THE MIDDLE AWASH,ETHIOPIA*

Recent investigation of the geochemical provenance of obsidian artefacts from spatially and temporally variable archaeological sites in Ethiopia has shown the diversity of geological sources and concomitant differences in the transport of raw material to archaeological sites, thus allowing reconstruction of the utilization of raw material by early hominids as well as recent humans. We recognize 30 compositionally different obsidians that were used at the Middle Stone Age (MSA) archaeological sites of Aduma (A8), Halibee Herto, Aladi Springs and Porc Epic in the Middle Awash region. Probable sources of nine of these obsidians are Adokoma, Ayelu, Ida'ale, Assebot, Asboli, Gira‐Ale and Kone. Many compositional types are confined to a single site, but others are shared between sites, although shared obsidians between sites more than 300 km apart are exceptional.     

A cost surface model of volcanic glass quarrying and exchange in Hawai‘i

The spatial distribution of artifacts from the Pu‘u Wa‘awa‘a volcanic glass source (North Kona District, Hawai‘i Island) shows a pattern of direct access by those living in the immediately vicinity of the source with subsequent down-the-line exchange. Most quarrying and exchanges likely occurred within a single day’s travel from sites where artifacts were deposited. The exception to this is the discovery of non-local direct access evident in assemblages from the extreme southern end of Hawai‘i Island; these visits may have involved voyages by canoe. While people did not often travel far for volcanic glass they nonetheless appear to have had unfettered accessed to source material and freely conducted inter-community exchanges. This implies volcanic glass was treated as a common pooled resource and the existence of informal exchange relationships.     

The Protohistoric Time Period in Northwest Ohio: Perspectives from the XRF Analysis of Metallic Trade Materials

This paper presents the results of an experimental study into the usefulness of X-ray florescence (XRF) in identifying the composition of metal artifacts found at aboriginal sites in northwestern Ohio. In the late 1990s, we subjected 96 samples to XRF and documented our results. We then compared our data to that collected by more precise spectrographic methods to assess the effectiveness of the XRF method for this application. While not precise enough to source native coppers, we conclude that XRF is a cheap, nondestructive method for differentiating native copper from its European counterparts at sixteenth- and seventeenth-century Late Woodland sites.     

Bromine in teeth and bone as an indicator of marine diet

Nitrogen isotope ratios in tissues are often used to aid in the reconstruction of the marine component of diets in past populations. Elevated δ¹⁵N values normally found with high trophic level marine resource consumption can, however, also be mimicked by physiological conditions (breastfeeding, pathological states affecting nitrogen balance), climate (aridity), and anthropogenic environments (manuring). This paper presents a pilot study testing whether bromine concentrations can provide a tool for teasing apart possible causes of variation in nitrogen isotope ratios. Blind analyses of bromine in archaeological samples correctly identified individuals derived from coastal vs. inland regions and high vs. low marine consumption time periods. Thus, bromine can provide an important supplement to other isotopic analyses of diet.     

The Copper CHARM Set: A New Set of Certified Reference Materials for the Standardization of Quantitative X‐Ray Fluorescence Analysis of Heritage Copper Alloys*

This paper introduces a new set of certified reference materials designed to aid scientists and conservators working in cultural heritage fields with quantitative X‐ray fluorescence analysis of historical and prehistoric copper alloys. This set has been designated as the Copper CHARM Set (Cultural Heritage Alloy Reference Material Set). The Copper CHARM Set is designed to be used by a wide range of museum‐, art‐ and archaeology‐oriented scientists and conservators to help improve the accuracy and range of their calibrations for quantitative ED–XRF spectrometry of copper alloys, and also increase the number of elements that can routinely be quantified. In addition, the common use of a single core set of the reference materials is designed to significantly improve inter‐laboratory reproducibility, allowing greater data sharing between researchers and thus furthering possibilities for collaborative study.