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The Caribbean islands witnessed a population expansion of ceramic‐using horticulturalists during the Early Ceramic Age (ca. 500 BC to 750 AD) from the Orinoco Valley to Puerto Rico. We examined 18 lithic artefacts from Guadeloupe and Dominica initially thought to be obsidian, a material believed to be absent from those islands. We investigated the volcanic or meteoritic origin of this unique and yet unknown material through observation (binocular, SEM, microtomography) and geochemical analyses (PIXE, SEM‐EDS, ED‐XRF, EPMA, LA‐ICP‐MS). Elemental analyses rule out the hypothesis of an origin from a meteoritic impact (i.e. identification as tektites). Most of the artefacts have an andesitic composition (<63% SiO2), which appears to be unique among ‘massive’ glasses. The only artefact with a rhyolitic composition has been traced back to the Guadeloupe's Volcan du Tuf, where glassy fragments have been collected and analysed. The geological source of the other vitreous artefacts that exhibit an andesitic composition could be from a sublocal subduction‐arc volcanism (maybe from Martinique), although no volcanic vitreous material of this kind has ever been reported worldwide. These results once again highlight the regional mobility of Early Ceramic populations and the production of standard lithic products using a highly original, albeit low‐quality, local lithic resource, and provide valuable references for future identification of similar materials. [ABSTRACT FROM AUTHOR]

The Salado and Verde streams constitute the two main seasonally available freshwater courses that flow into the Atlantic coast of the Río Negro province (continental Patagonia, Argentina, 42° South). This would have favored their use in the past as corridors for human circulation between the coast and the interior. This paper presents the results of the technomorphological and geochemical analyses of the obsidian artifacts recovered in the area to constrain mobility. The results allow us to propose the existence of toolkit reconditioning or replacement activities, and the identification of different sources of provenance of the obsidians (Sacanana, Telsen, and Portada Covunco, distant up to 800 km from the study area), reinforcing the hypothesis of a coast–inland circulation, with the possible existence of circuits of exchange of this raw material. [ABSTRACT FROM AUTHOR]

In archaeometry, the correct assignment of archaeological artefacts with their original geological sources continues to be an indispensable tool for determining exploitation patterns, trade routes, tool production and the movement of goods in ancient times. Statistically, Mahalanobis distance has been an integral part of the artefact provenance methodology. However, this method presents disadvantages when some of the theoretical assumptions are not fulfilled. In this way and with a focus on the veracity of the correct assignment of archaeological samples to their geological sources, we present a technique that employs a semi‐supervised classification based on finite mixture models. This procedure uses labelled and unlabelled data to assign samples to groups with the advantage that it does not depend on the sample size of the groups as required by Mahalanobis distance. This procedure was first applied in a controlled experiment where the exact origin of the samples is known in order to verify the accuracy of the method; afterwards, it was applied to artefacts recovered from the archaeological site of Xalasco, Tlaxcala (Mexico), from both surface and excavation collections and analysed with a portable X‐ray fluorescence spectrometer. The resulting groups defined that the ancient dwellers of Xalasco exploited six supply sources located in Central Mexico. [ABSTRACT FROM AUTHOR]

Portable X‐ray fluorescence (pXRF) geochemical analysis on obsidian from five Formative period (1200 BCE to AC 100) sites from Tlaxcala, Mexico, has revealed that most of the material had similar values to those found in the closest obsidian source, named El Paredón, Puebla. Nevertheless, initial analyses did not resolve whether these materials came from the same caldera or from a specific obsidian deposit. Here we present a methodology that allows the identification of obsidian subsources. The results reveal that Tlaxcalan populations took advantage of a specific obsidian deposit called Tres Cabezas, Puebla, providing valuable new data to identify associated regional exchange networks. [ABSTRACT FROM AUTHOR]

Stone‐tipped weaponry was important for the survival of past peoples, and many functional and non‐functional factors likely influenced their design. Two functional factors that past peoples likely considered in the design of their stone tips are durability (whether or not a stone tip breaks) and robusticity (how much damage is incurred upon breakage). Many factors have been shown experimentally to influence stone tip influence durability and robusticity, including stone raw material. Here, we further explore the relationship between stone raw material and stone tip durability and robusticity via controlled experiments comparing chert and obsidian. We first demonstrate with semi‐static fracture strength analyses that obsidian stone tips require less force to break than do chert stone tips. We then show with dynamic ballistics impact testing that obsidian stone tips are less durable and robust than chert stone tips. Our results are entirely consistent with previous experimental comparisons of chert versus obsidian stone tips, and support the hypothesis that past peoples, when presented with multiple raw materials, likely weighed their costs and benefits in the process of selection. [ABSTRACT FROM AUTHOR]

Obsidian archaeological artifacts from the Holocene occupation sequences at the contemporary sites of Mochena Borago and Yabello, southern Ethiopia, have been characterized using electron microprobe analysis. Results show the artifacts of each site were partially procured from two separate but known sources, Bantu and Chebe. The inhabitants of both sites also seem to have used obsidian from another, as yet unknown, source. This is interesting as the inhabitants of each site pursued different life ways: one entirely dependent on wild animals and the other incorporating domestic fauna. In spite of the analysis of many geological sources in the Ethiopian Rift System, the unknown sources cannot yet be determined. Despite erupting from several vents, one of the sources, Chebe, has uniform elemental chemistry, representing an exception to the widely held assumption that every eruptive sequence has unique chemistry, the archaeological significance of which should be further explored. [ABSTRACT FROM AUTHOR]

Obsidians sources used by prehistoric people in the Omolon River basin and neighbouring areas of north‐eastern Siberia were determined for 112 artefacts from 30 sites by the energy‐dispersive X‐ray fluorescence (ED‐XRF) method. The main suppliers were the primary obsidian sources in both the Chukotka (Lake Krasnoe) and Kamchatka (Itkavayam, Payalpan and KAM‐8) regions, with distances from sources to sites up to about 300–900 km in a straight line. For the first time, the transport of obsidian from Kamchatkan sources has been detected outside of this territory. The mechanism of obsidian transport was most probably by down‐the‐line movement, especially in the case of the Lake Krasnoe source. [ABSTRACT FROM AUTHOR]

Recent archaeological research has highlighted the potential role of mobile pastoral groups in the diffusion of raw materials and technological innovations between the southern Caucasus and north‐western Iran from the Neolithic onwards. Two successive projects, PAST‐OBS and SCOPE, were designed to explore this hypothesis through the study of obsidian consumption patterns from the Neolithic to the Bronze Age using a flexible analytical strategy that considerably extends the scale of obsidian studies in these regions. By focusing on the exploitation of obsidian at multiple levels—local, regional and interregional—we hope to unravel the complexity of the obsidian networks under study. The aim of this paper is to present (1) a reassessment of the work so far carried out by previous obsidian studies, with a view to homogenizing and to clarifying the nomenclature in use; and (2) an introduction to the PAST‐OBS and SCOPE projects in order to initiate a discussion of our preliminary results. [ABSTRACT FROM AUTHOR]

Obsidian was broadly used along the Andean Cordillera in South America. Particularly in Peru, its use can be traced to the earliest human occupations, continuously through pre‐Columbian times to contemporary Andean agro‐pastoralist societies. In order to distinguish the provenance of obsidians from Peru, this paper reports a new X‐ray fluorescence (XRF) analysis on several obsidians obtained in surface collections of the Ayacucho region. The analysis and source determination were made by XRF on 52 specimens. The source assignments involved comparisons between the compositional data for the specimens and the University of Missouri Research Reactor (MURR) XRF obsidian database for sources in Peru. After analysing the samples, obsidian sources were recognized and documented. All had small nodules not larger than about 4 cm. They were recovered from Ñahuinpuquio and Marcahuilca hill which belonged to the previously identified Puzolana source. Another identified source was the well‐known Quispisisa, located 120 km south of the city of Ayacucho, and distributed through a vast region in central Peru. The results expand previous observations made on the obsidian provenance at Ayacucho Basin, as well as the extension of the Puzolana source between Yanama and Huarpa hills, south of Ayacucho city. [ABSTRACT FROM AUTHOR]

In north‐western Patagonia, obsidian was used during the entire Holocene, and its importance increased with time. Recent fieldwork discovered a new obsidian source located in the Río Grande, which was called 'Coche Quemado' (CQ). The results indicate that the CQ source has a different geochemical signal than all other sources in the region. Its use is spatially restricted to piedmont and, to a lesser extent, the plains. Chronologically, CQ was exploited in the middle and late Holocene, and its use accounts for a range of spatial distribution between 150 and 200 km. [ABSTRACT FROM AUTHOR]

The results of the X‐ray fluorescence (XRF) analysis of 59 obsidian samples from 11 archaeological sites in the Auca Mahuida region of north‐western Neuquén, Argentina, are present. They indicate that several obsidian sources were used; however, the intensities of their exploitation were variable. Strong differences appear between the Colorado River basin, characterized by a low variability of obsidian groups from northern Neuquén; the Auca volcano, with a low variability of obsidian groups, but from local sources located north and southwards of the study area; and along Bajo del Añelo, which presents a high variability of obsidian groups from several local and non‐local sources. The pattern recorded fits different mechanisms of access to the sources and the conveyance of obsidian across the landscape. Two distinct paths of direct access are suggested for obsidian availability along the Colorado River in northern Neuquén and for Portada Covunco obsidian in central Neuquén. Additionally, the presence of obsidian from sources in southern Neuquén province (Cerro Las Planicies‐Lago Lolog), located about 350 km from the study area, is suggested. While not yet conclusive, this possibility parsimoniously integrates the available geochemical and spatial information, allowing the existence of either long‐distance transport or indirect access by exchange or similar mechanisms to be proposed. [ABSTRACT FROM AUTHOR]

This study presents a provenance analysis of the Neolithic obsidian assemblages from the early to mid‐sixth millennium bc settlement at Göytepe, Azerbaijan. The study is unique in that (1) it involves a complete, non‐selected obsidian assemblage (901 artefacts) from one particular area of the site; (2) the material is derived from a well‐stratified sequence of 10 securely radiocarbon‐dated architectural levels; and (3) the use of an extraordinarily wide range of sources (more than 20) was identified by provenance analysis using energy‐dispersive X‐ray fluorescence. The results reveal a previously unknown diachronic change in obsidian use in the region, suggesting the occurrence of significant socioeconomic changes during the Late Neolithic of the southern Caucasus. [ABSTRACT FROM AUTHOR]

Primary questions regarding the foraging behaviour of the first hunter–gatherers who colonized the New World are how they found, procured and utilized high‐quality raw materials for manufacturing stone tools. In this paper, we present evidence from the late Pleistocene site of Cueva Bautista in the highlands of south‐western Bolivia, which demonstrates that a substantial portion of the recovered stone tool assemblage originated in Cerro Kaskio, a recently discovered obsidian source located 15 km south‐west of the site. In addition to describing the geological and geochronological setting, we provide the first geochemical characterization of the Cerro Kaskio source by means of instrumental neutron activation analysis and energy‐dispersive X‐ray fluorescence. Supported on the technological analysis and archaeometric sourcing of the obsidian lithics found in Cueva Bautista, we discuss the nature of the procurement strategies practised by the earliest mobile hunter–gatherers who explored and colonized the Andean highlands. We conclude that opportunistic lithic resource procurement was probably an important component of the first foraging societies that explored the highland Andes. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In this study we applied a multidisciplinary approach, coupling geophysical and geochemical measurements, to unveil the provenance of 170 obsidian flakes, collected on the volcanic island of Ustica (Sicily). On this island there are some prehistoric settlements dated from the Neolithic to the Middle Bronze Age. Despite not having geological outcrops of obsidian rocks, the countryside of Ustica is rich in fragments of this volcanic glass, imported from other source areas. The study of obsidian findings was carried out first through visual observations and density measurements. At least two different obsidian families have been distinguished, probably imported from Lipari and Pantelleria islands. Analysing the magnetic properties of the samples, these two main sources were confirmed, but the possibility of other provenances was inferred. Finally, we characterized the geochemical signature of the Ustica obsidians by performing microchemical analyses through electron microprobe (EMPA) and laser ablation (LA-ICP-MS). The results were compared with literature data, confirming the presence of the Lipari and Pantelleria sources (Sicily) and indicating for the first time in this part of Italy a third provenance from Palmarola island (Latium). Our results shed new light on the commercial exchanges in the peri-Tyrrhenian area during the prehistoric age. [ABSTRACT FROM AUTHOR]

Long-distance networks for the transport of exotic goods and the beginnings of specialized craft production first appear in Mesoamerica during the Formative Period. The results of portable X-ray fluorescence (pXRF) analysis of 456 obsidian artefacts imported to the Pacific coast site of La Zanja (Guerrero, Mexico) indicate that long-distance exchange of finished obsidian blades along the coast began during the Early Formative (c.1400-1000 cal BC) and remained constant into the Middle Formative Period (c.800-550 cal BC). Comparisons with sourcing studies from elsewhere in Mesoamerica indicate the development of a major Pacific coast trade network during the Formative Period that linked coastal Guerrero to the central Mexican highlands and the Valley of Oaxaca. Weaker connections existed with Gulf coast obsidian trade networks that traversed the Isthmus of Tehuantepec. As the first obsidian sourcing study from coastal Guerrero, these data contribute to a greater understanding of the development of exchange networks in Mesoamerica during the Formative Period. [ABSTRACT FROM AUTHOR]

This paper aims to evaluate the optical properties of natural rhyolite obsidians that might be useful in the identification of different sources of archaeological samples. Even though colour, degree of alteration, crystaloclast composition and texture are important properties by which sources can be identified, all of these features do not always lead to an unambiguous distinction. In this regard, the refractive index (ND) becomes a helpful tool because it is not only sensitive to the chemical composition of natural glasses but also to their different thermal histories. Obsidians from six localities of Patagonia were analysed. Their refractive index measurements (ND) only range between 1.47 and 1.49, but the ND values of some of these sources are sufficiently constrained to allow discrimination between them. [ABSTRACT FROM AUTHOR]

The obsidian sources on the Erzurum- Kars Plateau have not been extensively surveyed, and their geochemical signatures are still poorly understood. Yet a significant number of artefacts from archaeological sites in Georgia and Armenia have produced chemical compositions that are unrelated to any Turkish or Caucasian source analysed so far. Their origins may lie in these poorly known deposits. The objective of the collaborative project undertaken by the University of Erzurum and the French mission ' Caucasus' is to study the sources of obsidian in the Erzurum and Kars regions, in order to shed light on the intensity of exploitation of this material, and to highlight the exchange networks that may have existed between north-eastern Turkey and the southern Caucasus. The analyses that we have carried out on the samples taken during this exploratory survey have enabled a definite extension of the territory of circulation of this obsidian to western Transcaucasia. The lack of knowledge concerning the diffusion of obsidian from the regions of Erzurum and Kars thus appears for the moment mainly related to insufficient geochemical characterization of the sources, confirming the importance of future surveys. [ABSTRACT FROM AUTHOR]

We tested two portable XRF instruments (with different technologies) using two correction schemes ('soils' and 'mining') with both factory-set calibrations and linear regression calibrations derived from published data. All four Aegean obsidian sources, including Sta Nychia and Dhemenegaki on Melos, were distinguished in each case. The newer instrument provided better 'off-the-shelf' accuracy than the older instrument, but calibrations negated these differences. The newer model also offered superior precision for most elements, despite measuring specimens for shorter times. Both correction schemes for the newer instrument resulted in almost equal precision, meaning that either may be used for successful Aegean obsidian sourcing. [ABSTRACT FROM AUTHOR]

A large analytical programme involving both obsidian source characterization and obsidian artefact sourcing was initiated recently within the framework of the French archaeological mission ' Caucasus'. The results will be presented in two parts: the first part, this paper, deals with the presentation and characterization of obsidian outcrops in the southern Caucasus, while the second presents some results obtained from a selection of artefacts originating from different Armenian sites dated to between the Upper Palaeolithic and the Late Bronze Age. The same analytical method, LA- ICP- MS (laser ablation inductively coupled plasma mass spectrometry), has been used to characterize all the studied samples (both geological and archaeological). This method is more and more widely used to determine the elemental composition of obsidian artefacts, as it causes minimal damage to the studied objects. We present in this first part new geochemical analyses on geological obsidians originating from the southern Caucasus ( Armenia, Georgia) and eastern Turkey. These data enhance our knowledge of the obsidian sources in these regions. A simple methodology, based on the use of three diagrams, is proposed to easily differentiate the deposits and to study the early exploitation of this material in the southern Caucasus. [ABSTRACT FROM AUTHOR]

Within the framework of the French archaeological mission ' Caucasus', in a previous paper we have presented new geochemical analyses on geological obsidians from the southern Caucasus ( Armenia, Georgia) and eastern Turkey. We present here the second part of this research, which deals with provenance studies of archaeological obsidians from Armenia. These new data enhance our knowledge of obsidian exploitation over a period of more than 14 000 years, from the Upper Palaeolithic to the Late Bronze Age. The proposed methodology shows that source attribution can be easily made by plotting element contents and element ratios on three simple binary diagrams. The same diagrams were used for source discrimination. As the southern Caucasus is a mountainous region for which the factor of distance as the crow flies cannot be applied, we have explored the capacity of the Geographic Information System to evaluate the nature and patterns of travel costs between the sources of obsidian and the archaeological sites. The role of the secondary obsidian deposits, which enabled the populations to acquire raw material at a considerable distance from the outcrops, is also considered. [ABSTRACT FROM AUTHOR]

This paper thematically characterizes a large body of recent obsidian sourcing discourse as a means of highlighting the current place of obsidian provenance studies in larger archaeological discourse. It is shown that the field of obsidian sourcing is flourishing, with a clear upward trend in the number of published studies in the past decade. This paper further argues that sourcing is a means to an end, a way to determine where artefacts originate, and thus a means of addressing broader archaeological problems. Through this contextual framework, obsidian sourcing studies-and indeed all provenance studies-are seen as relevant because they transcend the increasingly specialized world of archaeological discourse. [ABSTRACT FROM AUTHOR]

The geochemical compositions for obsidian from two of the most important sources on the Japanese island of Hokkaido, Shirataki and Oketo, are presented. This work represents the first systematic study of obsidian geochemistry on Hokkaido from the view of modern methodological standards. The study was performed with the help of neutron activation analysis to determine the concentrations for 28 elements. The results obtained allow us to subdivide both sources into two geochemical groups (Shirataki-A and -B; and Oketo-A and -B), with each representing an individual sub-source. Obsidian from both Shirataki and Oketo sources is identified at archaeological sites located on Hokkaido, on the neighbouring Sakhalin Island and Kurile Islands, and in the lower course of the Amur River basin. The distance of obsidian transport during the Upper Palaeolithic was up to ∼250 km, and in the following Neolithic and Palaeometal periods up to ∼1200 km. This testifies to the wide distribution of Hokkaido obsidian to archaeological complexes in North-East Asia and its active transport/exchange in prehistory. The data presented here should be used as a reference for the obsidian geochemistry of Shirataki and Oketo sources from now on. [ABSTRACT FROM AUTHOR]

Despite predictions in the 1980s that electron microprobe analysis (EMPA) would become a popular technique for obsidian sourcing, few studies have used it with this goal, and most of them are now outdated and unrepresentative of modern EMPA. For example, Merrick and Brown (1984) recorded their data on punch cards. Furthermore, these studies destructively prepared artefacts for analysis. The research at hand endeavoured: (1) to establish the modern capabilities of EMPA for obsidian sourcing; and (2) to develop and evaluate procedures for non-destructive artefact analysis. Issues such as diagenetic effects and compatibility with NAA and XRF data were also investigated. [ABSTRACT FROM AUTHOR]

The geological sources of obsidian in the Red Sea region provide the raw material used for the production of obsidian artefacts found in prehistoric sites on both sides of the Red Sea, as far afield as Egypt, the Persian Gulf and Mesopotamia. This paper presents the chemical characterization of five obsidian geological samples and 20 prehistoric artefacts from a systematically excavated Neolithic settlement in highland Yemen. The major element concentrations were determined by SEM-EDS analysis and the trace element concentrations were analysed by the LA-ICP-MS method, an almost non-destructive technique capable of chemically characterizing the volcanic glass. A comparison of archaeological and geological determinations allows the provenance of the obsidian used for the Neolithic artefacts to be traced to definite sources in the volcanic district of the central Yemen Plateau. [ABSTRACT FROM AUTHOR]

In west-central Neuquén Province, Argentina, in the area around Estancia Llamuco, west of Zapala, south of Las Lajas and north-east of Lago Aluminé, there are multiple primary and secondary sources of obsidian. Primary sources occur within the south-east extension of the Plio-Quaternary volcanic chain that runs from Copahue volcano through Pino Hachado. Secondary sources include river-bed gravels within the valleys of Arroyo Cochicó Grande and Río Kilca as far south as where this river joins with Río Aluminé, and the Quaternary fluvial-glacial sediments cut by the valley of Río Covunco as far east as Portada Covunco. Visually variable obsidians from these two secondary sources include homogeneous black and grey-translucent types, porphyritic and banded types, and an abundant quantity of oxidized red and black obsidian. However, all these visually distinct obsidians have similar and unique chemistry, with Ba between 220 and 340 ppm, different from any other obsidians previously reported from Neuquén, which all have Ba > 500 ppm, as do obsidians from sources to the north in Mendoza and to the west in Chile. This chemical distinctive obsidian has been exploited and transported over a wide area, beginning prior to 4000 bp, and occurs in local archaeological sites, as well as sites ≥ 300 km to the north-east in La Pampa Province, ∼430 km to the south in Chubut Province, and >75 km to the west across the Andean drainage divide in Chile. [ABSTRACT FROM AUTHOR]

Obsidian is an effective material for the study of prehistoric raw material use and exchange, due to the high degree of homogeneity and redundancy of obsidian materials and manufactured objects in the archaeological record. The destructive nature of many analytical techniques often impedes compositional research because of the damage that may occur to priceless archaeological artefacts. The combination of time-of-flight (TOF) ICP-MS with a laser ablation sample introduction system provides a highly efficient means of chemically characterizing obsidian. This study shows that sample size limit capabilities of TOF-ICP-MS analysis of obsidian can reach less than 100 μm. Sampling and analysis of microartefacts enables researchers to overcome problems of sampling bias with very little damage to the valuable existing materials within the archaeological record and expands the potential for chemical compositional analyses in archaeology. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 . 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. [ABSTRACT FROM AUTHOR]

A collection of 50 archaeological obsidian samples studied in the framework of the Preciudadela Project (Teotihuacan, Mexico) has been analysed using particle-induced X-ray emission (PIXE) with the external beam line of the Accélérateur Grand Louvre d'Analyse Elémentaire facility (C2RMF, Paris) and of the Instituto de Física (UNAM, Mexico). This work addresses the provenance of these obsidian samples, with the purpose of determining if they come from the obsidian sources exploited by Teotihuacans (mainly Otumba and Sierra de Pachuca), from other sources, or arrived via commercial exchanges with other regions. For that, the elemental compositions derived from the PIXE spectra have been compared with data published in the literature on the basis of instrumental neutron activation analysis. From the concentrations of selected key elements (Na, K, Mn, Fe, Zn, Rb, Sr, Zr), it was possible to unambiguously assign the provenance of most samples. Many originate from two major sources, namely Sierra de Pachuca (Hidalgo) and Otumba (Mexico), which were the main obsidian deposits used by the Teotihuacans. However, some samples exhibit a compositional fingerprint matching other provenances, i.e., Paredón (Puebla) and Zacualtipan (Hidalgo). [ABSTRACT FROM AUTHOR]

PIXE–PIGME analysis of 19 obsidian artefacts from Lakeba Island in east Fiji identified contact with northern Vanuatu in the post-colonization period ( c. 2500–1000bp) of Fiji. The Lakeba obsidian is the only physical evidence for interaction across the 850 km water gap separating the archipelagos of Vanuatu and Fiji in the first millenniumad. New research on the Vanuatu obsidian sources with laser ablation – inductively coupled plasma – mass spectrometry (LA–ICP–MS) casts serious doubt on the validity of a long-distance inter-archipelago connection in the post-Lapita era. This paper presents the re-analysis of 18 obsidian artefacts from Lakeba using LA–ICP–MS and radiogenic isotope results that demonstrate that the Lakeba obsidian is not from Vanuatu, and it most likely derives from the Fiji–Tonga region. Geochemical evidence for long-distance interaction and migration between the West and Central Pacific in the post-Lapita era has yet to be identified. [ABSTRACT FROM AUTHOR]

In 2005–2006 we initiated a major archaeological survey and chemical characterization study to investigate the long-term use of obsidian along the eastern shores of Lake Urmia, northwestern Iran. Previous research in the area suggested that almost all archaeological obsidian found in this area originated from the Nemrut Daĝ source located in the Lake Van region of Anatolia (Turkey). More recent research on obsidian artefacts from the Lake Urmia region has identified a significant number of obsidian artefacts with compositions different from the sources near Lake Van. This suggests that the obsidian artefacts are from a yet to be identified geological source, but possibly one that was not too distant. In order to advance our knowledge of Iranian obsidians and eventually refine provenance criteria we analysed obsidian from 22 Chalcolithic sites and some source areas. The compositions of both obsidian source samples and artefacts were determined using wave length dispersive X-ray fluorescence spectrometry (WDXRF). This paper presents results from the trace elemental analysis of both geological and archaeological obsidians, providing important new data concerning the diachronic relationship between lithic technology and raw material in the north-west of Iran. [ABSTRACT FROM AUTHOR]

X-ray fluorescence and laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS) analyses conducted on 40 obsidian samples from the Late Chalcolithic 2 levels at Tell Hamoukar and Tell Brak in north-east Syria have shown trends towards the exploitation of obsidian sources in the eastern Taurus. While the Bingöl region appears to provide the majority of obsidian to both sites, there is also evidence of more minor exploitation of a source in the Lake Van area and an altogether unknown source (X). This paper presents the data acquired from the analyses of the archaeological obsidian and situates these results within their chronological and regional contexts. [ABSTRACT FROM AUTHOR]

The site of Rocchicella, near Catania, in eastern Sicily, has yielded important archaeological evidence from prehistoric times to the Middle Ages. Extensive archaeological investigations of cultural layers dating from the Palaeo-Mesolithic to the Copper Age have recently been undertaken, and volcanic glass, mainly obsidian, has been collected in the course of excavation. To determine the provenance of this volcanic glass, a non-destructive elemental analysis was carried out to measure the concentration of characteristic trace elements. The analysis was carried out using a new XRF spectrometer equipped with a beam stability controller and a quantitative method developed at the LANDIS laboratory of the INFN–CNR Institutes of Catania. In addition to the obsidian, it was demonstrated for the first time that a local vitreous material similar to obsidian, but displaying a completely different composition, was used during all the investigated periods. This material was identified as a basaltic glass, characterized by a superficial product of devitrification called palagonite. Analysis of the obsidians has led to the identification of the island of Lipari as the provenance source. High- and low-power microscopic use-wear analysis on obsidian and basaltic glass artefacts indicated that soft wood and plant matter might have been processed at the site. [ABSTRACT FROM AUTHOR]

A non-destructive analytical method using wavelength-dispersive X-ray fluorescence (WDXRF) that allows the establishment of the provenance of archaeological obsidians was developed and a comparison with the classical XRF method on powders is discussed. Representative obsidian samples of all the geological outcrops of archaeological interest of the Mediterranean area (Lipari, Pantelleria, Sardinia, Palmarola and the Greek islands of Melos and Gyali), were analysed with the normal procedures used in rock analysis by XRF (crushing, powdering and pelletizing). The non-destructive XRF analysis was instead conducted on splinters taken from the original geological pieces, with the shape deliberately worked to be similar to the refuse usually found at archaeological sites. Since the analysis was conducted on the raw geological fragment, intensity ratios of the suitably selected chemical elements were used, instead of their absolute concentrations, to avoid surface effects due to the irregular shape. The comparison between concentration ratios (obtained by traditional XRF methods) and the intensity ratios of the selected trace elements (obtained from the non-destructive methodology) show that the different domains of the chemical composition, corresponding to the geological obsidians of the source areas, are perfectly equivalent. In the same way, together with the geological splinters, complete archaeological obsidians, from Neolithic sites, may be analysed and their provenance may be determined. The proposed non-destructive method uses the XRF method. Due to its sensitivity, low cost and high speed, it is surely an extremely valid instrument for the attribution of the provenance of the archaeological obsidian from Neolithic sites. [ABSTRACT FROM AUTHOR]

For 50 years, archaeologists and physical scientists have been dating, determining the composition of and measuring stone tools, and reporting them in Archaeometry and many other journals. In Archaeometry specifically, the number of papers devoted to the analysis of lithic material has increased at least 30 times since 1958 and volume 1. This is a reflection not only of an increase in the number of scholars devoting their time to the archaeometry of stone, but also of increases in the quality and quantity of instrumental technology available to researchers in the field. [ABSTRACT FROM AUTHOR]

Recently, several archaeometrical projects have been started on the prehistoric collection of the Hungarian National Museum. Among the analytical methods applied, non-destructive prompt gamma activation analysis has a special importance. We have also tested the potential of this method on chipped stone tools, with the aim of determining their exact provenance. On the basis of major and trace element components, characterizations of stone tools and their raw materials—silicites (flint, chert, radiolarite and hornstone) as well as volcanites (felsitic porphyry and obsidian)—were performed. We discuss some important results concerning each group, as case studies. Compiling the data set of different PGAA analysis series, compositions of 110 samples are reported, including 76 archaeological pieces. In the future, we plan to extend the number of investigated objects in each class. [ABSTRACT FROM AUTHOR]

A neutron activation programme aimed at archaeological provenance research operated at The Hebrew University of Jerusalem between the years 1974 and 1997. The history and accomplishments of that laboratory are presented. Endeavours to preserve unpublished results are described. Results on Cypriote pottery are presented. [ABSTRACT FROM AUTHOR]

Descriptions of the history of the Archaeometry Laboratory at the University of Missouri Research Reactor and the procedures used for instrumental neutron activation analysis of archaeological materials are presented. The laboratory was established in 1988 to support students and faculty from the University of Missouri and other universities who were interested in archaeological research involving compositional analysis. The results obtained from the analysis of obsidian sources and artefacts from locations in the continental USA are presented for illustration. [ABSTRACT FROM AUTHOR]

The Elemental Analysis Laboratory provides research support for campus users and service analyses for the University, other state and governmental agencies and private industry. The laboratory's primary concern is the application of unique methodology to a wide range of analytical problems that arise in the course of efforts by University researchers. For the past decade or so, compositional analysis by neutron activation analysis of archaeological artefacts for the purpose of studying provenance, trade or cultural patterns of prehistoric populations has become an area of focus. The present communication will discuss the laboratory in general and the scope and significance of the archaeology work done within the organization. A brief example of a current project involving the study of geologic samples from prehistoric stone tool quarries from American Samoa is presented as an illustration. [ABSTRACT FROM AUTHOR]

Neutron activation analysis has contributed to research in Peru in different scientific fields, particularly in archaeometry. In archaeometry, applications include the characterization of copper alloy artefacts from the tomb of El Señor de Sican to determine production methods, ceramics from the Wari Culture to study production, and distribution of Middle Horizon pottery in Cuzco, ceramics from Villa El Salvador to determine production groups, and obsidian source analysis. [ABSTRACT FROM AUTHOR]

The water diffusion mechanism in obsidian has been revisited with the advent of a new dating approach employing secondary ion mass spectrometry (SIMS). The water diffusion SIMS(+) profile and the concept of a surface saturation (SS) layer in obsidians both provide a sound basis for the new diffusion age equation (SIMS-SS) and are supported by dated world examples ( Liritzis et al. 2004 ). Here, we present the basic physical–chemical analysis of the mass transport phenomenon on which the new dating method is based. The crucial age parameter of the SIMS-SS dating approach for archaeological obsidians—that is, the surface saturation (SS) layer—is supported by both theoretical and experimental data. [ABSTRACT FROM AUTHOR]

Obsidian geochemical analysis has become an indispensable tool in archaeological research and has wide applications. However, in spite of the abundance of geological and archaeological obsidian, there has been virtually no such investigation in Ethiopia. Recent instrumental characterization of 31 obsidian artefacts from the Middle Stone Age site of Porc Epic and numerous obsidian geological sources show that artefacts were being transported from as far as 250 km away. We believe this has relevance to the understanding of the emergence of modern human behaviour. [ABSTRACT FROM AUTHOR]

article introducing an exciting, potentially precise and inexpensive method of dating obsidian artefacts has thus far failed to reach its potential. Numerous efforts to refine, improve and even redevelop the method since that time have similarly failed to achieve the original promise. Only within the last eight years have significant improvements been made, due to both improved analytical techniques and a better understanding of the hydration process. However, most of our mechanistic understanding of the interaction of water with rhyolitic glass is based on experiments performed on melts and glasses at temperatures above their glass transitions, conditions inappropriate for investigation of near-surface environmental conditions. Unfortunately, studies detailing the temporal evolution of the diffusion profile at low temperatures are rare, and few useful data are available on the low-temperature diffusive hydration of silicate glasses. This paper presents data on the experimental hydration of obsidian from the Pachuca source (a.k.a. Sierra de las Navajas, Basin of Mexico) at 75°C for times ranging from 3 to 562 days, and compares these results with data for samples obtained from a stratigraphic excavation of the Chalco site in the Basin of Mexico. Samples have been analysed using secondary ion mass spectrometry (SIMS) to provide concentration/depth data. While 75°C is still significantly above the temperatures at which archaeological obsidians hydrate, it is well below the glass transition temperature (approx. 400°C) and thus processes are likely to be similar to those that occur in nature, but fast enough to be observed over a laboratory timescale. The results demonstrate that a simple square-root-of-time model of the evolution of the diffusion profile is not adequate to describe the diffusion process, as measured diffusion profiles exhibit the effects of concentration- and time-dependent, non-Fickian diffusion. With progressive hydration, characteristic diffusion coefficients first decrease, then increase with time. Surface concentration increases with time, but an intermediate plateau is observed in its time evolution that is consistent with results obtained from the suite of Chalco samples. Both of these effects have been observed during diffusion in glassy polymer systems and are associated with the build-up and relaxation of self-stress caused by the influx of diffusing material. [ABSTRACT FROM AUTHOR]