Obsidian from the Epipalaeolithic and Neolithic eastern Maghreb. A view from the Hergla context (Tunisia)

In the present paper, it is shown that in the Hergla area (eastern Tunisia), obsidian was present from the early to at least the late sixth millennium cal BC. The presence of cores indicates that obsidian knapping was at least partly carried out in situ. The origin of these obsidians was determined from their elemental composition, by comparison with those originating from western Mediterranean potential sources, including analyses of new samples from the nearby Pantelleria Island. All obsidians were measured following the same protocol, by particle induced X-ray emission or by scanning electron microscopy/energy dispersion spectrometry. All the Hergla obsidians were found to originate from the Balata dei Turchi sources of Pantelleria. A review of the present body of knowledge on eastern Maghreb suggests, in spite of the still very preliminary data available, that Pantelleria was almost its unique provider of obsidians from the Epipalaeolithic to and during the Neolithic. However, the relative importance of the two main Pantellerian sources of Balata dei Turchi and Lago di Venere as providers of obsidian to eastern Maghreb remains to be investigated.     

Empires and resources: Central Anatolian obsidian at Urkesh (Tell Mozan,Syria) during the Akkadian period

Almost all of the obsidian used to craft stone tools in the Near East from the Palaeolithic onward originated from volcanoes in two geographic regions: Central Anatolia and Eastern Anatolia. Five decades of obsidian sourcing has led to the view that Central Anatolian obsidians largely followed the Mediterranean coast and rarely reached farther east than the Middle Euphrates, whereas Eastern Anatolian sources almost exclusively supplied sites east of the Euphrates. This paper discusses the identification of Central Anatolian obsidian artefacts at the Bronze-Age site of Tell Mozan (Urkesh) in northeastern Syria. Most of the obsidians at Tell Mozan (97%) came from the Eastern Anatolian sources, as expected from established distribution models. Artefacts of Central Anatolian obsidian, however, were excavated from one well-constrained context: the deposits on a palace courtyard that date to the height of the Akkadian empire's influence at this third-millennium Hurrian religious and political centre. In particular, the obsidian came from the Kömürcü source of Göllü Da?. Potential explanations for this exotic obsidian are discussed. This obsidian might have “piggybacked” on the distribution of Central Anatolian metals or arrived at this city as royal gifts or prestige items. Other discussed mechanisms include Akkadian-linked changes in either territoriality involving pastoral nomads responsible for the arrival of Eastern Anatolian obsidians or identity construction of elites based on involvement in Central Anatolian economic and political networks.     

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.     

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.     

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.     

The application of Mössbauer spectroscopy to the characterisation of western mediterranean obsidian

Iron-57 Mössbauer absorption spectra have been measured for samples of obsidian from known geological flows and from archaeological site material from the western Mediterranean region. Of the four main sources available to prehistoric man it is possible to distinguish Sardinian (SA) and Pantellerian obsidian from Lipari obsidian on the basis of differences in the local atomic surroundings of iron atoms, as determined from the Mössbauer spectra. There is, however, some overlap between Lipari and Pontine Island obsidians. The Gabellotto flow on Lipari is readily identified through the presence of magnetite inclusions. The ratio of ferric to ferrous ions is found to be much higher in the surface layers (< 60 μm) than in the bulk obsidian as detected using Mössbauer backscattering.     

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.     

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.     

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.     

The distribution and provenance of archaeological obsidian in central and eastern Europe

The sources of archaeological obsidian in central and eastern Europe are briefly described and analyses of 48 samples from 10 of these sources in northeast Hungary and southeast Slovakia are reported. Instrumental Neutron Activation Analysis was used to determine 16 trace elements and two major elements. Principal Components Analysis supported by Discriminant Analysis showed seven analytical groups in these data. A total of 270 pieces of archaeological obsidian were assigned by Discriminant Analysis to three of the Carpathian source groups defined, the remaining four source groups not being represented in the archaeological record. The three source groups used are: (1) Szöllöske and Málá Toron?a in Slovakia (designated group Carpathian 1); (2) Csepegö Forrás, Tolcsva area, Olaszliszka and Erdöbénye in Hungary (Carpathian 2a); and (3) Erdöbénye (Carpathian 2b). Carpathian 2a and 2b type obsidians are both found at the re-deposited source of Erdöbénye. Carpathian obsidian was used most widely in Hungary, Slovakia and Romania, and also reached south to the Danube in Yugoslavia, west to Moravia, Austria and to the Adriatic near Trieste, and north to Poland. Carpathian 2a obsidian was used in the Aurignacian period, Carpathian 1 in the Gravettian and Mesolithic, and Carpathian 1, 2a and 2b in the Neolithic, when Carpathian 1 predominated and obsidian use was at its most intensive. Only Carpathian I type has been identified in the Copper and Bronze Ages. There is no evidence at present for any overlap between the Carpathian obsidian distribution and the distributions of the Near Eastern or Aegean sources, but there is an overlap with Mediterranean obsidian at the Neolithic site of Grotta Tartaruga in northeast Italy where Liparian and Carpathian 1 material were identified. The distribution of obsidian from the Carpathian sources is considered in terms of linear supply routes. Based on limited available evidence the supply zone is significantly smaller and the rate of fall-off with distance slightly lower than that reported for Near Eastern obsidians.     

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.     

Obsidian source characterization in the Cordillera Real and eastern piedmont of the north Ecuadorian Andes

Recent research in the Quijos and Cosanga valleys of the eastern piedmont of Ecuador’s Cordillera Real has revealed and substantiated previous knowledge of obsidian sources that are unrelated to obsidian flow systems in the Sierra de Guamaní, Ecuador. Neutron Activation Analysis (NAA) and X-ray Fluorescence (XRF) were carried out on 47 obsidian source samples collected from several contexts in and adjacent to the study area. From samples within the study area three distinct obsidians were characterized: Cosanga A, Cosanga B, and Bermejo. These obsidians originate from a number of obsidian-bearing rhyolitic domes recently identified in the hills west of the Río Cosanga. Extensive survey of these dome localities has identified obsidian cobbles large enough for formal and informal tool manufacture. Beyond the study area, samples were collected and analyzed from the El Tablón source in the Sierra de Guamaní, providing much needed data on this poorly understood source. In addition, a sample from the newly identified Conda Dome source, near the Cotopaxi volcano, was characterized with XRF. All samples were then compared to 57 pre-existing samples from the Mullumica–Callejones, Yanaurco–Quiscatola and Carboncillo sources in the Ecuadoran Cordillera Real, as well as to artifacts from the Sumaco area in the Ecuadorian Amazon. Results of the elemental characterization indicate that the Cosanga Valley, El Tablón and Conda Dome obsidians are chemically distinct. Further, visual characteristics of Cosanga Valley obsidian types are useful in source attribution for the large artifact samples from the region. Finally, obsidian collected from the El Tablón flow suggests that this source may have produced obsidian suitable for tool manufacture.     

XRF obsidian analysis from Ayacucho Basin in Huamanga province,south-eastern Peru*

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.     

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.     

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 .     

Distinguishing Nemrut Dağ and Bingöl A obsidians: geochemical and landscape differences and the archaeological implications

Distinguishing the geochemically similar Bingöl A and Nemrut Da? peralkaline obsidians is a major challenge in Near Eastern obsidian sourcing. Despite abundant claims in the literature otherwise, this study reveals that Bingöl A and Nemrut Da? obsidians are distinguishable with adequate source sampling and highly accurate and repeatable data for geochemically important elements. Earlier research has endeavored to link a simple geochemical trend (peralkalinity) to specific locations at Nemrut Da?, but existing schemes to distinguish Bingöl A and Nemrut Da? obsidians cannot validly link compositional clusters to the landscape. This study demonstrates that additional elements are required to attribute artifacts to specific obsidian-bearing lava flows at the volcano. Limitations of this newly analyzed collection of geo-referenced Nemrut Da? and Bingöl specimens suggests caution is still warranted in sourcing peralkaline obsidians, but a few archaeological implications are clear. New sourcing results from Tell Mozan in northeastern Syria refute a widespread assumption that one can use maximal efficiency to deduce whether peralkaline obsidian artifacts originated from Nemrut Da? or Bingöl A. The ability to discern among these sources also enables inquiries into issues of cultural and technological preferences regarding these obsidians.     

Possible obsidian sources for artifacts from Timor: narrowing the options using chemical data

Measurements made at the Australian National University using laser ablation ICPMS show that none of the 88 analyzed obsidian artifacts from East Timor match either the known Papua New Guinea or the five Island SE Asian source samples in our ANU collections. There is a coastal journey of more than 3000 km between the occurrence of obsidians from the Bismarck Archipelago volcanic province of Papua New Guinea and the Sunda-Banda Arc volcanic chain, yet obsidian artifacts from the two important PNG sources of Talasea and Lou Island are found at coastal Bukit Tengkorak in eastern Sabah at a similar distance along with material that has no known source. Timor lies south of the eastern section of the active volcanic Banda Arc island chain but it is within range of possible rhyolite sources from there. Although there is a continuous chain of around 60 active volcanoes stretching from west Sumatra to the Moluccas most are basaltic to andesitic with few areas likely to produce high silica dacite–rhyolite deposits. This does not exclude the possibility that the volcanic landscapes may contain obsidian, but without detailed survey and chemical analysis of sources from the Sunda-Banda Arc the attribution of the Timor obsidian artifacts remains to be demonstrated. Timor may seem to be an unlikely source for the presence of obsidians as it lacks reports of the silica-rich rhyolite volcanic centers necessary to produce this material. Despite the absence of detailed survey and analysis of Indonesian obsidian sources, especially from the volcanically active Banda Arc, this paper presents evidence that one of two obsidian sources is clearly from Timor while the other, with less certainty, is also from an unknown local source.     

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 origins of Bondi Cave and Ortvale Klde (NW Georgia) obsidians and human mobility in Transcaucasia during the Middle and Upper Palaeolithic

Using PIXE four types of elemental compositions were found among obsidian artefacts from the Bondi Cave and Ortvale Klde, Middle to Upper Palaeolithic sites in NW Georgia. One of those types corresponds to obsidians from the Chikiani source, whose compositions were determined with a very good agreement by PIXE and ICP-AES/MS. The composition of Chikiani obsidians is remarkably constant despite K–Ar and ³⁹Ar/⁴⁰Ar extrusion ages from ca 2.4 and 2.8 Ma. The compositions of two other groups of obsidian artefacts are similar to source materials from eastern Anatolia and Armenia, in particular Ikisdere, Sarikamis, Gutansar, and Hatis. Obsidian is only a minority component in the lithic assemblages at the Bondi Cave and Ortvale Klde. Both Neanderthal and Modern Human populations used obsidian in particular from Chikiani. Considering that the shortest walking distance to this nearest source is at minimum of about 180 km, and to other potential sources of more than 350 km it is suggested that this material reached these two sites mostly, if not exclusively, by a series of ‘down the line’ exchanges.     

Sources of obsidian artefacts,exchange networks and landscape use in Auca Mahuida (Neuquén,north-western Patagonia)

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.