Picking up The Pieces: Reconstructing Lithic Production Strategies at a Late Holocene Obsidian Quarry in Southern Kenya

Use of particular lithic quarries by different cultural groups is a prominent feature of the Pastoral Neolithic period in southern Kenya (ca. 3200–1400 b.p.), when lifeways based on herding domesticated livestock spread through eastern Africa. Here, I present lithic attributes from the recently excavated Elmenteitan Obsidian Quarry assemblage to examine the site’s role in an obsidian distribution network spanning southwestern Kenya. Evidence from the quarry reflects intensive preparation of blade cores and blade reduction. Changes in platform size, flake scar orientation, curvature, and cortical rates through the reduction sequence permit a preliminary reconstruction of Elmenteitan core production strategies that can serve as a basis for regional comparative studies. Uniformity in blade core design and reduction strategy suggests highly organized use of the quarry and supports its role as a production center for regional exchange. Results inform regional debates and contribute to a growing literature on the potential of quarry archaeology.     

Obsidian sources and distribution systems in Island Southeast Asia: a review of previous research

This paper summarises research on obsidian findings across the region of Island Southeast Asia (ISEA), from the first reporting of obsidian on Sumatra as a result of cave excavations in the early 1900s through to the latest published discoveries in 2009. These results are the background for the first region-wide research project focussing on obsidian characterisation and its role in prehistoric inter-island exchange. It is commonly held that distribution of obsidian in ISEA was only localised and inter-island transportation limited. The review, however, suggests that this hypothesis derives from an incomplete knowledge of obsidian distribution in the region rather than typifying prehistoric social patterns. Obsidian sourcing has been carried out only intermittently in ISEA since the 1970s and has generally been focussed only at the single site level, thus explaining this very partial understanding.     

Towards a Multi-Agent-Based Modelling of Obsidian Exchange in the Neolithic Near East

This paper examines an alternative approach to previously proposed models of prehistoric exchange such as the law of monotonic decrement or the down-the-line exchange model developed by Renfrew (Proceedings of the Prehistoric Society 34: 319–331, 1968, Renfrew 1977) to explain the distribution of obsidian across the Near East during the Neolithic period. Renfrew’s down-the-line model, which results in a very regular and clustered network, does not permit the circulation of obsidian to regions of the Near East that are further than 300 km from the source zones, as is shown in the archaeological data available. Obsidian exchange is a complex system where multiple factors interact and evolve in time and space. We therefore explore Agent-Based Modelling (ABM) so as to get a better understanding of complex networks. ABM simulations of an exchange network where some agents (villages) are allowed to attain long-distance exchange partners through correlated random walks are carried out. These simulations show what variables (population density, degree of collaboration between villages…) are relevant for the transfer of obsidian over long distances. Moreover, they show that a type of small-world exchange network could explain the breadth of obsidian distribution (up to 800 km from source) during the Near Eastern Neolithic.     

Through the Glass Darkly: Prehispanic Obsidian Procurement and Exchange in Southern Peru and Northern Bolivia

Recent discovery of the major geological sources of Central Andean obsidian permits a new understanding of the patterns of obsidian procurement and exchange by the Prehispanic societies of southern Peru and northern Bolivia. Based on the trace element analysis of obsidian artifacts from 160 archaeological sites, it can be established that the two major deposits of obsidian were being exploited by 9400 BP, and that volcanic glass was being transported over long distances throughout Andean prehistory. Inhabitants of the Cuzco region acquired most obsidian from the Alca source in central Arequipa, while those in the high plateau surrounding Lake Titicaca obtained most obsidian from the Chivay source in southern Arequipa. Obsidian evidence suggests close ties between the Cuzco and Circum-Titicaca regions throughout prehistory, except during the Middle Horizon (ca. 1400–1050 BP), when the expansion of the Huari and Tiahuanaco states disrupted this pattern.     

Recent Research on Obsidian from Missouri Archaeological Sites

Obsidian has been noted at archaeological sites in the Midwest for over 160 years, although very few artifacts made from this material are recorded in archaeological contexts in Missouri. Background research revealed that only 16 obsidian artifacts from 13 sites had been documented from the state and that only 5 of the specimens had been geochemically analyzed and attributed to a source. Recent excavations at the Droste site (23PI1291), a Late Woodland period site in northeast Missouri, yielded two obsidian artifacts. The two specimens from the Droste site along with two previously unsourced obsidian artifacts from the Burkemper site (23LN104) and two from the Stapleton site (23HD110) were tested for trace element composition via X-ray fluorescence analysis. This article reports the results of these geochemical analyses, reviews the other obsidian artifacts reported from Missouri, and examines the cultural context and source of obsidian artifacts from other states in the upper Midwest.     

TRANSPORT AND SUBSISTENCE PATTERNS AT THE TRANSITION TO PASTORALISM,KOOBI FORA,KENYA

The Turkana Basin in Kenya has an extensive record of Holocene activities relating to mobility and economy of foraging and herding communities. Obsidian is only known from a few key localities in northern Kenya. As such, the use of obsidian as a toolstone material, commonly used during the mid‐Holocene, provides one way to trace exchange, interaction and population movements during the transition to pastoralism. We employ X‐ray fluorescence to characterize obsidian artefacts from four Pastoral Neolithic assemblages. Data reveal a highly mobile and diversified population that used watercraft to access and transport obsidian resources. Specifically, the use of the North Island obsidian source in Lake Turkana indicates that boat use was significant during this transitional period. The incorporation of watercraft transport and aquatic resources in our analyses of Pastoral Neolithic sites affords a greater understanding of subsistence, mobility and economy in this important period in East African prehistory.     

Obsidian provenance for prehistoric complexes in the Amur River basin (Russian Far East)

The sources of high quality volcanic glass (obsidian) for archaeological complexes in the Amur River basin of the Russian Far East have been established, based on geochemical analyses by neutron activation and X-ray fluorescence of both ‘geological’ (primary sources) and ‘archaeological’ (artifacts from the Neolithic and Early Iron Age cultural complexes) specimens. A major obsidian source identified as the Obluchie Plateau, located in the middle course of the Amur River, was found to be responsible for supplying the entire middle and lower parts of the Amur River basin during prehistory. The source has been carefully studied and sampled for the first time. Minor use of three other sources was established for the lower part of the Amur River basin. Obsidian from the Basaltic Plateau source, located in the neighboring Primorye (Maritime) Province, was found at two sites of the Initial Neolithic (dated to ca. 11,000–12,500 BP). At two other sites from the same time period, obsidian from a still unknown source called “Samarga” was established. At the Suchu Island site of the Early Neolithic (dated to ca. 7200–8600 BP), obsidian from the ‘remote’ source of Shirataki (Shirataki-A sub-source) on Hokkaido Island (Japan) was identified. The range of obsidian transport in the Amur River basin was from 50 to 750 km within the basin, and from 550 to 850 km in relation to the ‘remote’ sources at the Basaltic Plateau and Shirataki-A located outside the Amur River valley. The long-distance transport/exchange of obsidian in the Amur River basin in prehistory has now been securely established.     

Book Reviews

Abstract

Obsidian studies play an integral part in archaeology around the world, particularly in the Americas, but few archaeologists have employed obsidian studies to understand Native American life at historical archaeological sites. Yet, obsidian sourcing and hydration analysis can provide critical insights into site chronology and use, lithic recycling, and procurement and trade at contact and colonial sites. Obsidian geochemical sourcing and hydration analyses of a 19th-century rancho site in northern California have revealed new information on Native Americans who labored there in the second quarter of the 19th century. The obsidian data indicate a significant amount of lithic manufacture and use, a change in obsidian procurement in the 1800s, and an unprecedented number of obsidian sources represented on-site. The implications for general obsidian studies, as well as for regional archaeological issues, concern the problems with popular sourcing methods in northern California and the need to revisit current understandings of the first micron of hydration rim development.     

Coastal Maya Obsidian Tool Use and Socio-Economy in the Late Postclassic-Early Spanish Colonial Period at San Pedro,Ambergris Caye,Belize

Microscopic use-wear analysis of the obsidian artifacts recovered from Late Postclassic-Early Spanish Colonial occupations at the site of San Pedro yields useful information for interpreting Maya socio-economic activities. Obsidian traded into the community was used for a variety of tasks with emphasis placed on subsistence and domestic manufacture associated with marine resources, including intermittent and contingent crafting. Trade in obsidian and marine resources likely provided San Pedro community members access to inland economic networks and enabled the acquisition of resources not found on the caye. Microwear on chert and obsidian tools indicates relative stability in the traditional lives of the San Pedro Maya in the 15th–17th centuries a.d. Although the San Pedranos likely suffered to some degree from coastal raiding and the introduction of epidemic diseases by the Spaniards, their off-shore location provided them some protection from the upheaval experienced by the Maya in mainland communities.     

Initial source evaluation of archaeological obsidian from the Kuril Islands of the Russian Far East using portable XRF

Obsidian artifacts recently have been recovered from 18 archaeological sites on eight islands across the Kuril Island archipelago in the North Pacific Ocean, suggesting a wide-ranging distribution of obsidian throughout the island chain over the last 2,500 years. Although there are no geologic sources of obsidian in the Kurils that are known to have been used prehistorically, sources exist in Hokkaido, Japan, and Kamchatka, Russia, the southern and northern geographic regions respectively from which obsidian may have entered the Kuril Islands. This paper reports on the initial sourcing attempt of Kuril Islands obsidian through the analysis of 131 obsidian artifacts. Data from this research were generated through the application of portable XRF technology, and are used to address research questions concerning prehistoric mobility, exchange, and social networking in the Kuril Islands.     

Obsidian hydration dating: accuracy and resolution limitations imposed by intrinsic water variability

Obsidian hydration dating typically yields a range of ages for a single chronometric measurement, even after controlling for source chemistry and effective hydration temperature. Previously published data suggest that this range is due to hydration rate variations caused by variability in the concentration of intrinsic water, and specifically hydroxyl ions, in the obsidian. Such variability exists within any given obsidian source, and even within any particular specimen. This paper analyzes the effect on age estimates of intrinsic water variability and concludes that if a controlled sample of obsidian yields a range of ages, there is no way to tell whether the range is due to long site use or to variations in hydroxyl concentration. At present there is no robust and cost-effective protocol for measuring hydroxyl concentration. Suggested guidelines for obsidian hydration dating are developed using a case study. These findings do not invalidate obsidian hydration as a chronometric technique, but they do suggest limits to the temporal resolution achievable.     

Obsidian types from Holocene sites around Lake Turkana,and other localities in northern Kenya

Obsidian has been widely used by early Holocene hunter-gatherers and succeeding Pastoral Neolithic peoples in northern Kenya. Here we report the results of over 2000 electron microprobe analyses of artifactual and non-artifactual obsidian from the greater Lake Turkana region. Of the 15 compositional types of obsidian observed, a preponderant type is widespread across the region from the Barrier in the south to Ileret in the north and east as far as Kargi. This obsidian is the principal type at Lowasera and most Pastoral Neolithic sites, including the Jarigole Pillar site and Dongodien (GaJi4). The source of this obsidian is not known, but based on its distribution the source may be located on the Barrier or in the Suguta Valley immediately to the south of Lake Turkana. Although there are several possible sources of local obsidian identified for minor types, in stark contrast to the central part of the Kenyan Rift, major sources of obsidian available for artifact manufacture are not known in the Lake Turkana region. The lack of obsidian from demonstrable Ethiopian Rift and central Kenyan Rift sources, and the absence of obsidian with compositions found at the Turkana area sites in assemblages in the central part of the Kenyan Rift suggests that the earlier Pastoral Neolithic peoples around Lake Turkana interacted with each other, but perhaps not as strongly with people farther south along the Rift Valley, even as herding practices were expanding to the southward into central Kenya.     

Obsidian sources and distribution systems in Island Southeast Asia: new results and implications from geochemical research using LA-ICPMS

This paper discusses new evidence of long-distance interaction networks in Island Southeast Asia obtained from geochemical analyses using SEM-EDXA and LA-ICPMS of 101 obsidian samples from 25 locations including seven obsidian sources and 19 archaeological sites. Given that there are obsidian sources distributed throughout much of Island Southeast Asia, the potential for obsidian studies to provide greater understanding of patterns of mobility and exchange in the Pre-Neolithic and Neolithic periods would seem to be considerable. This potential, however, remains largely unrealised as obsidian sourcing has hitherto only been carried out intermittently in Island Southeast Asia using PIXE-PIGME, XRF and other methods.     

Obsidian Diffusion Dating by Secondary Ion Mass Spectrometry: A Test using Results from Mound 65, Chalco,Mexico

Secondary ion mass spectrometry (SIMS) was used to measure hydrogen and other elemental concentrations as a function of depth in ten obsidian artifacts (Pachuca Source), each with a well-constrained ¹⁴C date, from Mound 65, Chalco, Mexico. Hydrogen depth profiles for the different artifacts all display a characteristic S-shape, and increasing maximum hydrogen content in each profile and profile depths are well correlated with time. These data are used to investigate the potential use of Obsidian Diffusion Dating by SIMS (ODDSIMS) for both extrinsic and intrinsic dating of obsidian artifacts. Using “characteristic points” on the hydrogen profile (half-fall depth, inflection point depth), simple hydration rate equations were evaluated against time constraints provided by associated ¹⁴C dates. We demonstrate that neither the traditional OHD equation for depth (x) as a function of the square root of time (t^1/2) nor a linear function (t¹) fit the data. Solving the more generalized tⁿ function provides an excellent fit between characteristic point depths and ¹⁴C dates (for n≈0·75), and meets the constraint that at time equal to zero, the depth of the hydration profile must also be zero. However, this may be an average coefficient over the range of ages available, and may not accurately reflect rates at shorter or longer times. Using only two obsidian samples and their associated ¹⁴C dates, a calibration curve can be derived that provides ODDSIMS dates for the other pieces that are in excellent agreement with associated¹⁴ C dates, indicating that empirical application of the technique is potentially feasible, at least at individual sites.The underlying processes governing hydrogen transport into the obsidian were also investigated by using finite difference modelling to reproduce the shape of the hydrogen depth profile. Excellent fits were obtained by assuming concentration-dependent diffusion, and dates that agree well with associated ¹⁴C dates can also be extracted from the finite difference profiles. Although considerable additional work needs to be done, the success of the finite difference modelling suggests that development of an independent, intrinsic ODDSIMS model may be possible.     

THE OBSIDIAN IN THE AEGEAN BEYOND MELOS: AN OUTLOOK FROM YALI

Summary.   Obsidian is an important material circulated throughout the Aegean. Melian obsidian is found at many sites and researchers have concentrated on Melos without acknowledging obsidian from other sources. This article endeavours to highlight obsidian of non-Melian origin, such as that from the Carpathians, central Anatolia, Antiparos and, particularly, Yali. It is demonstrated that this latter source was a central one for certain islands, with its obsidian found at a number of sites in the Dodecanese and beyond. It is also emphasized that there were circulation modes of obsidian parallel to that of Melos, as well as different procurement conditions. Therefore, by including important regional sources such as Yali in the obsidian discourse, our understanding of obsidian exchange and circulation is enriched.     

Obsidian procurement,least cost path analysis,and social interaction in the Mimbres area of southwestern New Mexico

For over 15 years chemical compositional analyses of obsidian artifacts recovered from archaeological sites in the southwestern United States have been increasingly used to address many research agendas. Despite this increasing interest in obsidian studies, few have attempted to synthesize the ever-growing amount of data generated from the numerous projects being conducted in the southwest. Here, we synthesize and present data for 923 sourced obsidian samples recovered from over 80 archaeological sites in the Mimbres area of southwestern New Mexico. We then use least cost path analysis as a means of investigating procurement patterns as well as networks of social interaction within the region.     

OBSIDIAN IN THE MEDITERRANEAN AND THE NEAR EAST: A PROVENANCING SUCCESS STORY

Obsidian provenancing studies comprise one of the most productive and successful research programmes of archaeological science. Obsidian characterization has been successful because workable obsidian is homogeneous on a small scale, analysable by a large number of methods, and is restricted to a small number of mainly readily distinguishable geological sources. Analytical, dating, source, and trade studies within the western Mediterranean, central and eastern Europe, the Aegean, and Anatolia and the Near East during the last 30 years or so are reviewed. Research has shown that distributions are mainly separate in the four regions examined, and that obsidian was traded up to 900km in the prehistoric period. Publications on obsidian in the areas under review reached a peak of frequency in the later 1970s and 1980s, but have now decreased in number. This may reflect changing fashions in archaeometric studies, and a current lack of routine application of the provenancing methods developed.     

Long distance trinket trade: Early Bronze Age obsidian from the Negev

The discovery of three small obsidian flakes at the Camel Site in the central Negev, Israel, constitutes the first discovery of obsidian in Early Bronze Age contexts in the Negev and Sinai. Obsidian hydration analysis and X-ray microprobe analysis confirm the association of the artifacts with the site and the period, and indicate origins in Eastern Anatolia, in significant contrast to the exclusively Central Anatolian source of Southern PPNB obsidian. The structure of the obsidian trade system in the Early Bronze Age seems to contrast significantly with its Neolithic predecessor, and may be related to a system of pastoral nomadic exchange.     

Sources of Archaeological Obsidian on Sakhalin Island (Russian Far East)

Instrumental neutron activation analysis was performed on 79 obsidian tools and flakes from 35 sites on Sakhalin Island dating from Upper Paleolithic (c. 19,000 bp ) to Early Iron Age (c. 2000–800 bp ). Due to the absence of volcanic glass on Sakhalin Island, raw materials from the nearest obsidian sources on Hokkaido Island, such as Oketo, Shirataki, Tokachi-Mitsumata, and Akaigawa, were also analysed. A strong correlation between the chemical compositions of obsidian artefacts from Sakhalin and volcanic glass sources from Hokkaido was discovered. In particular, the Oketo and Shirataki sources were used for tool manufacturing throughout all of Sakhalin Island's prehistory. The distances between sources and archaeological sites range from 200–1000 km. The intensive exchange of raw materials continued and even intensified after the appearance of the La Pérouse (Soya) Strait between Hokkaido and Sakhalin about 10,000–8000 bp. The Sakhalin Island populations were deeply involved in the obsidian exchange network centered on Hokkaido.     

Obsidian hydration dating by infrared spectroscopy: method and calibration

Low temperature (90–190 °C) hydrothermal experiments have been conducted on seven obsidians where composition of the glass varies significantly in the concentration of structural water within the unhydrated bulk material. Infrared transmission spectroscopy was used to track the diffusion of molecular water into the glass surface as a function of time and temperature. Long-term (60–360 days) hydration sequences at 90 °C show a t^0.6 time dependence for the mass uptake of molecular water that forms the hydration layer. The structural water concentration of the unhydrated bulk obsidian is highly correlated with the pre-exponential and activation energy and may be used to estimate the Arrhenius constants. In addition, secondary ion mass spectrometry (SIMS) hydrogen profiling of Napa Glass Mountain obsidian hydrated at 90 °C reveals that the early stages of diffusion exhibit a dynamic behavior that includes a fluctuating hydrogen concentration and a changing diffusion coefficient that slows with time.