PROVENANCE STUDIES OF CHALCOLITHIC OBSIDIAN ARTEFACTS FROM NEAR LAKE URMIA, NORTHWESTERN IRAN USING WDXRF ANALYSIS

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.     

NON‐DESTRUCTIVE ANALYTIC METHOD USING XRF FOR DETERMINATION OF PROVENANCE OF ARCHAEOLOGICAL OBSIDIANS FROM THE MEDITERRANEAN AREA: A COMPARISON WITH TRADITIONAL XRF METHODS*

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.     

New Data on the Exploitation of Obsidian in the Southern Caucasus (Armenia,Georgia) and Eastern Turkey,Part 2: Obsidian Procurement from the Upper Palaeolithic to the Late Bronze Age

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.     

MULTIPLE PRIMARY AND SECONDARY SOURCES FOR CHEMICALLY SIMILAR OBSIDIANS FROM THE AREA OF PORTADA COVUNCO,WEST‐CENTRAL NEUQUÉN,ARGENTINA

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.     

DISTRIBUTION AND CONTEXT OF WORKED CRYSTALLINE ARTIFACTS FROM THE MIDDLE CUMBERLAND REGION OF TENNESSEE

Antiquarian and modern explorations within the Middle Cumberland region of Tennessee have uncovered vast quantities of ceramic, stone, bone, and shell artifacts. Objects made from mineral resources represent a modest percentage of the overall artifact assemblage. Specimens manufactured from crystals comprise a very small portion of the mineral sample, as only six worked crystalline artifacts are documented to date for the Middle Cumberland region. These specimens of fluorite and calcite consist of four earplugs, one bird effigy pendant, and one bead from four different Mississippian period sites. Fluorite and calcite deposits occur within the study area, but additional research is needed to determine whether these sources were used to make the Middle Cumberland items. The recovery of three earplugs (two of which are very unusual) and raw calcite crystals from the Castalian Springs mound complex comprises intriguing evidence for the production of crystalline objects as a site activity.     

Environment and collapse: Eastern Anatolian obsidians at Urkesh (Tell Mozan,Syria) and the third-millennium Mesopotamian urban crisis

The Early to Middle Bronze Age transition in Northern Mesopotamia has received great attention for the apparent concurrence of aridification, deurbanisation, and the end of the Akkadian empire around 2200 BCE. Our understanding of the “crisis” has been almost exclusively shaped by ceramics, demography, and subsistence. Exchange and the associated social networks have been largely neglected. Here we report our sourcing results for 97 obsidian artefacts from Urkesh, a large urban settlement inhabited throughout the crisis. Before the crisis, six obsidian sources located in Eastern Anatolia are represented among the artefacts. Such a diversity of Eastern Anatolian obsidians at one site is hitherto unknown in Mesopotamia. It implies Urkesh was a cosmopolitan city with diverse visitors or visitors with diverse itineraries. During this crisis, however, obsidians came from only two of the closest sources. Two to three centuries passed before varied obsidians reappeared. Even when an obsidian source reappears, the raw material seems to have come from a different collection spot. We discuss the likely exchange mechanisms and related social networks responsible for the arrival of obsidians at Urkesh and how they might have changed in response to climatic perturbations and regional government collapse.     

EMPLOYING TL METHODS FOR THE VERIFICATION OF MACROSCOPICALLY DETERMINED HEAT ALTERATION OF FLINT ARTEFACTS FROM PALAEOLITHIC CONTEXTS

The reconstruction of past human use of fire is often based on the presence of fire in archaeological sites as evidenced by alterations of lithic material. Here, a simple test based on thermoluminescence (TL) methods is used as a verification tool for the macroscopic identification of burning damage on flint microartefacts from the Early and early Middle Pleistocene site of Gesher Benot Ya‘aqov (Israel). The small dimensions of the microartefacts often prevented the removal of the outer surface, for which the TL signal might have been altered (bleached) by exposure to light during excavation. Bleaching of the TL signal by sunlight was found for fresh raw material, but appeared to be less problematic for the archaeological material, presumably due to patination. However, TL results for some samples are ambiguous and it is sometimes difficult to distinguish heating from post‐depositional bleaching, especially for samples that are macroscopically considered as not having been heated. A qualitative interpretation of the TL data is compared with the macroscopic assessment. The general agreement of the TL analyses with the macroscopic observations provides an independent verification of the observed burning and thus supports the assumption that fire was used and controlled throughout the long occupational sequence of Gesher Benot Ya‘aqov.     

STUDYING TECHNOLOGICAL PRACTICES AT A LOCAL LEVEL: NEUTRON ACTIVATION AND PETROGRAPHIC ANALYSES OF EARLY CERAMIC PERIOD POTTERY IN CENTRAL CHILE*

We discuss neutron activation and petrographic analyses of domestic ceramics and some raw materials from five archaeological sites in the Valdivia de Paine locality, in Central Chile. During the time period studied, the area was occupied by small‐scale horticultural groups with disperse and sedentary or semi‐sedentary settlement patterns. The analyses indicate that diverse local raw material sources were used in pottery production, and shared by members of different co‐residential units and between different cultural groups. The data indicate as many similarities as differences among the technological practices of pottery‐producing groups who lived in spatial proximity. The results have implications for the understanding of pottery‐producing communities at a local level, as well as small‐scale groups in general.     

AN ASSESSMENT OF BACK-SCATTERED ELECTRON PETROGRAPHY AS A METHOD FOR DISTINGUISHING MEDITERRANEAN OBSIDIANS

The recent application by Burton and Krinsley (1987) of back-scattered electron (BSE) petrography to obsidians from sources located in the south-western United States established that this method can effectively resolve and characterize included micro-crystalline phases that have proven difficult to analyse by optical thin-section microscopy. In the first extension of their original study, we have examined, using BSE petrography, obsidians from island sources located in the Mediterranean, including sources known to have been exploited in prehistory. Because of the kinetic contrasts on their crystallization, these microcrystalline phases reflect the magmatic history of the obsidian, providing information about superheating, supercooling, sub-solidus processes, and other phenomena. This information is of significance for the chemical analysis of Mediterranean obsidians and also as the basis for a powerful alternative to existing non-destructive analytical methods for the sourcing of archaeological and art-historical obsidian.     

Magnetic Sourcing of Obsidians in Southern South America: Some Successes and Doubts

Sourcing of archaeological obsidians is of great importance in unravelling the cultural, social and economic development of many ancient societies. Use of magnetic properties of obsidian fragments has been reported as a cheap, fast and versatile tool for these purposes. One hundred and seventy-six obsidians from archaeological sites and sources in Argentina and southern Chile were analysed magnetically using the weight-normalized intensity of JNRM (Intensity of Natural Remanent Magnetization), the intensity of JSIRM (Intensity of Saturation of Isothermal Remanent Magnetization) at 0·35 T and the bulk susceptibility. The method allowed identification of at least two different sources for archaeological materials found respectively to the north and south of the Lago Argentino, in SW Santa Cruz province, Argentina. Comparison of values from most samples in south and central Santa Cruz with those from a known source may lead to the interpretation that most of them belong to that source. In contrast, a critical analysis of the resolution of this using a larger than usual number of samples from three well distant obsidian sources in Argentina showed that two of the sources showed an almost complete overlapping of these three parameters, and all displayed a very large dispersion of values. This different result indicates that the magnetic sourcing of obsidians may not always have the resolution previously portrayed, but is applicable in certain localities.     

ARCHAEOLOGICAL VOLCANIC GLASS FROM THE SITE OF ROCCHICELLA (SICILY,ITALY)*

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.     

Geochemical composition of source obsidians from Kenya

Here we provide a reference resource to archaeologists interested in the sources of obsidian in Kenya, through electron microprobe analyses of 194 obsidian samples from 90 localities. Averaged analyses of each sample and eleven published analyses are categorized into 84 compositional groups of which only about 21 are known to have been used to produce artifacts, possibly because studies of artifactual material in the region are lacking. We also provide trace element analyses determined by XRF and LA-ICP-MS for these same obsidians. In northern Kenya 27 distinct compositions of obsidian have been found, including some of Miocene age, but the source of the most abundant obsidian found in archaeological sites in this part of Kenya remains obscure. The Baringo region contains at least 13 varieties of low-silica obsidian. The Naivasha–Nakuru region contains an abundance of obsidian with 38 compositional types recognized, and is the only region in Kenya apart from the Suregei (northern Kenya) that contains rhyolitic obsidian. Nine compositionally distinct types of obsidian are known from southern Kenya. Although Kenyan obsidians span the compositional range from phonolite to rhyolite, low-silica, nepheline-normative obsidians occur only south of 1°N latitude. One obsidian type, the Lukenya Hill Group, appears to have been derived from a regionally extensive ash flow tuff with a distribution of over 8000 km². From previous studies it is known that obsidians of lowest (Mundui) and highest iron content were used for tool manufacture, as were some obsidians (e.g., Kisanana) with the highest alkali content, and obsidians with both high (Njorowa) and low (Kisanana) silica content.     

PROBLEMS OF PHASING: A RECONSIDERATION OF THE BLACK PATCH MIDDLE BRONZE AGE 'NUCLEATED VILLAGE'

The Middle Bronze Age settlement complex of Black Patch, East Sussex, originally considered to represent the remains of a single phase 'nucleated village', is here reconsidered as representing the remains of two chronologically distinct settlement units. The dangers inherent in overlooking sequence and assuming contemporaneity for all archaeological features revealed within the course of a single excavation, are outlined.     

Sources of archaeological volcanic glass in the Primorye (Maritime) Province,Russian Far East*

Geochemical studies of volcanic glasses (obsidians and perlites) from geological outcrops (N = 80) and archaeological collections (N = 110) were performed in order to determine source provenance in Primorye (Russian Far East), using neutron activation analysis and X‐ray fluorescence spectrometry. Three major sources of archaeological volcanic glass were identified, two relatively local and one more remote. Several minor sources detected in the archaeological assemblage have not been located. This study suggests that long‐distance obsidian exchange between Primorye and adjacent North‐East Asia has existed since c. 10 000 bp .     

Early Neolithic obsidians in Sardinia (Western Mediterranean): the Su Carroppu case

All the obsidians from the undisturbed Early Neolithic (Cardial ware phase I) layer of the Su Carroppu rock-shelter (Sardinia island) were studied. Their elemental composition and that of obsidians from the Monte Arci (Sardinia) volcanic complex was determined by ion beam analysis (PIXE). A comparison between the composition of Su Carroppu artefacts, analysed non-destructively, and that of Western Mediterranean analysed in the same conditions shows that the archaeological material belongs to the SA, SB2 and SC Monte Arci-types, to the exclusion of the SB1 type. The typological/technological study of this industry allowed us to reconstruct two chaînes opératoires, for the production of blades (using predominantly SC obsidians) and of flakes (based exclusively on SA and SB2 obsidians), respectively, but on the whole, assemblage blade/bladelet production was performed somewhat preferably with SA and SB2 types. Thus, in the earliest EN culture known on the island, ancient man had, for the making of its obsidian toolkit, a highly adaptive behaviour applied to the reduction of different useful obsidian sources.     

Ecological Patterns in the Upper Pleistocene and Holocene in the Jebel Gharbi, Northern Libya: Chronology, Climate and Human Occupation

Surveys and test excavations in the Jebel Gharbi have brought to light a large quantity of prehistoric sites indicating intensive human occupation from the Upper Pleistocene to the Holocene. Several radiometric dates (standard ¹⁴C, AMS and U/Th) provide a detailed framework of the absolute chronology of the local peopling of the area. Generalised Middle Stone Age archaeological materials represent the earliest term of reference in the geological series. Aterian complexes are well-represented, being widely spread throughout the mountain range and in the lowlands. Lower Later Stone Age, or “Dabban”, artefacts are also attested to both geological and archaeological sequences. Human occupation continued with the Upper and Final Epipalaeolithic (or “Iberomaurusian”) and later, with Capsian and Neolithic groups. Permanent and seasonal water springs and raw material sources influenced settlement strategy and selected areas offered particularly favourable conditions and became intensively occupied.     

New Data on the Exploitation of Obsidian in the Southern Caucasus (Armenia,Georgia) and Eastern Turkey,Part 1: Source Characterization

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.     

Stone tools for the hunt: points with impact scars from a Middle Paleolithic site in southern Italy

We present the find of impact scars on six Middle Paleolithic points from the rock shelter site of Oscurusciuto in southern Italy, dated to MIS 3. We review our knowledge of hunting weapons in the European Middle Paleolithic, the available evidence for the use of Mousterian points as spear tips and the interpretations of impact scars. Our identifications are based on comparisons to similar scars observed on experimental material and archaeological material of known function, made of the same raw materials (cryptocrystalline varieties of silica) as the points from the Oscurusciuto site. The scarce evidence available prior to our work suggested that at least some Mousterian points were used to tip hand-delivered spears already by MIS 6 (i.e. between 186 and 127 ka). The evidence from Oscurusciuto confirm that Neanderthals in Western Europe sometimes used Mousterian points to tip spears to hunt large and medium size mammals, like the fauna present at the Oscurusciuto site. The significance of this sample is not diminished by its small size, as indicated by a discussion of the factors that influence the frequencies of impact scars in different archaeological samples and a review of comparable evidence from residential sites of similar and younger ages.     

Petrographic thin sections and exotic rocks provenience among hunter–gatherer societies in the eastern Pampa–Patagonia Transition (lower basin of the Colorado River,Argentina)*

Lithic assemblages recovered from sites located in the eastern Pampa–Patagonia transition include a great diversity of raw materials, some from neighbouring regions, such as the Humid and Dry Pampa subregions and Northpatagonia. Lithic raw material assignments to specific procurement areas were preliminarily proposed based on macroscopic characterizations. The aim of the paper is to present the results obtained from the petrographic thin sections of archaeological artefacts from Middle and Late Holocene sites recorded at the study area. The analyses corroborate most of the macroscopic determinations, and more detailed knowledge of the acquisition areas of these raw materials was obtained.     

THE PROVENANCE OF OBSIDIAN ARTEFACTS FROM THE WĀDĪ ATH‐THAYYILAH 3 NEOLITHIC SITE (EASTERN YEMEN PLATEAU) BY LA–ICP–MS

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.