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.     

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.     

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.     

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.     

Geochemical Variability in the Paredón Obsidian Source,Puebla and Hidalgo,Mexico: A Preliminary Assessment and Inter‐Laboratory Comparison

Chemical characterization reveals intra‐source variation in obsidian from the Paredón source area in Puebla and Hidalgo, Mexico. Two chemical sub‐sources of obsidian from Paredón are spatially discrete and cannot be distinguished by visual characteristics. To facilitate future investigations of the prehistoric exploitation of these sub‐sources, an inter‐laboratory comparison of elemental concentrations is presented based on neutron activation analysis and several XRF instruments.     

Application of electron microprobe analysis to identify the origin of ancient pottery production from the Castillo de Huarmey,Peru

A vast amount of ceramics (among other grave goods) were recovered from Castillo de Huarmey, a Wari culture (650–1050 ce ) archaeological site on the north coast of Peru. In order to assess ceramic production area(s) and possible trade, political or cultural interactions with other regions, and to complement earlier petrographic analysis, electron microprobe analysis (EMPA) was conducted following a rarely used methodology in archaeology. The chemical composition of individual minerals in ceramics and sediments samples from the Huarmey Valley was obtained, focusing mainly on amphiboles, feldspars and pyroxenes. The results of the analyses clearly indicate that the majority of the ceramic analysed was made of raw material of local origin.     

Smalt production in the Ore Mountains: Characterization of samples related to the production of blue pigment in Bohemia

The study deals with the chemical composition of samples related to the production of a blue pigment/smalt. The samples examined come from the regions of Soví huť and Horní Blatná (north-west Bohemia) dating to the 16th and 17th centuries. These locations are often mentioned in relation to the discoverer of smalt production technology: Christopher Schürer. The aim of the study is to evaluate the chemical composition of samples from both localities as well as with respect to the ores occurring in the given regions. The samples can be divided into two basic groups. The first clearly represents smalt (potassium glass coloured with cobalt), while the second apparently constitutes the samples of the so-called ‘speiss’ (an aluminosilicate mass with metallic compounds). The analysis of the smalt confirmed the representation of minor elements bismuth and nickel (always) and uranium and molybdenum (rarely), which are found in Co ores from the Ore Mountains. The paper is the first to present the composition of actual blue pigment finds originating directly from the production sites, while the available literature has so far only reported the results of analyses of the pigments already used when referring to the Ore Mountains.     

The manufacturing process of 3rd millennium BC bone based incrusted pottery decoration from the Middle Guadiana river basin (Badajoz,Spain)

The aim of this study is to present the manufacturing process developed on 3rd millennium BC white incrusted pottery from the middle Guadiana River basin (Badajoz, Spain), alongside the analytical procedure developed to determine the nature of these incrustations. The analytical procedure developed in this paper will assess the nature of these incrustations as burnt bone and in fewer cases as calcium carbonate, turning upside down the usual tendency for the Iberian Peninsula, where calcium carbonate has been the only kind of incrustation identified up until now. The analytical facilities used are: SEM-EDX, XRF microprobe, XRD and FTIR. The assessment of the nature of the incrustations as burnt bone has been a hazardous task and it has been necessary to develop a procedure using several analytical techniques and reference materials.     

CHARMed PyMca,Part II: An evaluation of interlaboratory reproducibility for ED‐XRF analysis of copper alloys

CHARMed PyMca is a protocol for researchers using energy‐dispersive X‐ray fluorescence spectroscopy (ED‐XRF) who wish to maximize interlaboratory reproducibility of quantitative results from copper alloys found in heritage materials. This paper reports the results of a study evaluating the interlaboratory reproducibility expected when following this protocol. Five institutions participated in this study, using nine tube‐based instruments of seven types. A set of 12 reference materials not used for calibration was analysed according to the protocol. The results show an improvement in reproducibility of between 65% and 83%, depending on the element, in comparison with a similar study carried out in 2010. The protocol allowed the consistent reporting of concentrations for 15 elements, in contrast to only eight elements that were reported in the 2010 study. Finally, the protocol was shown to generate accurate quantitative results with a well‐characterized precision. It is hoped the information presented here can help researchers studying heritage copper alloys to collaborate more effectively and with greater confidence in the reproducibility of their results. It should also aid researchers to make realistic and informed decisions about whether or not the degree of reproducibility that they may expect from ED‐XRF makes the protocol suitable for their specific purposes.     

Ceramic Production in the Kur River Basin (Fars,Iran) During the Middle to Late Second Millennium bce: A Geochemical and Technological Characterization

A total of 119 middle to late second millennium bce pottery samples from six sites in the Kur River Basin (Fars, Iran) were examined to characterize these ceramics and reconstruct their manufacturing technology and the origin of the primary materials. For this, a combined study of handheld XRF and thin‐section petrography was performed. The geochemical signatures of these ceramics were defined and interpreted in their archaeological and geological framework, resulting in the determination of different production processes and clay types used for four ceramic wares (Middle Elamite, Qaleh, Shogha and Taimuran) and the identification of possible outcrops used for Shogha–Taimuran production.