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.     

The magnetic sourcing of obsidian samples from Mediterranean and near Eastern sources

The magnetic properties of obsidians are examined for their potential in sourcing obsidian artifacts. The three simplest to determine magnetic parameters—initial intensity of magnetization, saturation magnetization and low field susceptibility—are found to be effective discriminants of many Mediterranean, Central European and near Eastern sources. Although the between-source precision is not as good as geochemical analyses of minor and rare-earth elements, the technique demonstrated the existence of new sources that were subsequently confirmed by minor element analyses. Unfortunately some key sources do not appear to be readily distinguishable on these three simple magnetic parameters alone, although more sophisticated magnetic analyses may prove diagnostic. Despite this, it would appear that effective discrimination can be made in many cases, occasionally with more precision than minor element analyses. This technique therefore offers, as a minimum, a preliminary sourcing tool for use in many areas of the world, thus reducing the number of expensive geochemical analyses. Furthermore, its very low cost, non-destructive nature and speed open the possibility of quantitative evaluation of trade routes based on obsidian distributions, particularly as versions of the equipment are now suitable for use in the field.     

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.     

Characterization of New Zealand obsidian using PXRF

New Zealand has some of the most active areas of rhyolitic volcanism in the world and this has produced numerous obsidian sources in the northern half of the North Island. In total archaeologists have recognized 27 named locations from which obsidian can be obtained scattered across 4 geological source regions. Shortly after colonization in the late 13th century AD Polynesian settlers began transporting this material some thousands of kilometers throughout the country and across the sea in small quantities to distant neighbors in the Kermadecs and Chatham islands. Although considerable research has been conducted on obsidian sourcing in New Zealand the complexity of geochemical source discrimination and the lack of a practical method of non-destructive geochemical analysis has hindered progress. We present the results of our use of PXRF to provide geochemical data on New Zealand obsidian sources and to compare the use of discriminant analysis and classification tree analysis to discriminate among sources and attribute archaeological samples to sources. Our research suggests that classification tree analysis is superior to discriminant analysis in sourcing studies. A large case study using an important settlement phase site (S11/20) from the Auckland region demonstrates the utility of the methods and the results support a model of high degrees of mobility and interaction during the early settlement of New Zealand.     

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.     

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.     

Comparison of XRF and PXRF for analysis of archaeological obsidian from southern Perú

Chemical sourcing is becoming an increasingly important component of archaeological investigation. Instruments used for elemental analysis generally must be operated in a controlled laboratory environment. Further, many methods require destruction of a small portion of the objects under investigation. These facts inhibit the application of chemical sourcing studies in a number of research contexts. Use of portable non-destructive instruments would resolve these issues. Sixty-eight obsidian artifacts from the site of Jiskairumoko, in southern Perú, were examined by X-ray fluorescence spectrometry (XRF) and portable X-ray fluorescence spectrometry (PXRF). Results were compared for consistency in terms of source determination and individual element concentrations. Both instruments determined that the same sixty-six artifacts derived from the Chivay obsidian source and both identified the same two artifacts that could not be assigned to source. Individual element comparisons showed significant differences, but these can be resolved through instrument cross calibration, and differences had no bearing on source identification. PXRF was found suitable for determining obsidian sources in southern Perú and for identifying specimens that require more sensitive analytical methods such as, instrumental neutron activation analysis (INAA). Regular use of Chivay at Jiskairumoko suggests consistent trade relationships developed during the Archaic.     

AN ASSESSMENT OF THE CURRENT APPLICATIONS AND FUTURE DIRECTIONS OF OBSIDIAN SOURCING STUDIES IN ARCHAEOLOGICAL RESEARCH*

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.     

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.     

Assessing the applicability of portable X-ray fluorescence spectrometry for obsidian provenance research in the Maya lowlands

Recent innovations in portable energy-dispersive X-ray fluorescence (PXRF) spectrometry have increased its utility for the geochemical characterization of obsidian artifacts for archaeological provenance research. However, concerns over the utility of PXRF instrumental analyses have been raised, focused on the validity and reliability of the geochemical data produced. Here we adopt the framework of Richard Hughes (On Reliability, Validity, and Scale in Obsidian Sourcing Research, 1998), whereby reliability addresses instrument stability and issues of measurement while validity pertains to an instrument’s ability to discern geochemical source provenance. This is done in order to test the utility of PXRF instruments for archaeological provenance research. k-Means cluster analysis was used to test the accuracy of PXRF through statistical comparison of data acquired via laboratory and portable energy-dispersive XRF instruments. Multivariate analysis was employed to demonstrate obsidian source representation at two Classic Maya archaeological sites in southern Belize – Uxbenká and Ek Xux – and to test the validity of data obtained from a PXRF instrument in answering archaeological research questions pertaining to regional interactions between lowland Maya polities. Results suggest that portable XRF instruments produce internally consistent results. However, data acquired from a PXRF instrument are not statistically equivalent to other XRF instruments. This is to say that while PXRF is not a reliable technique, it is valid for questions pertaining to geochemical source representation.     

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.     

Forensic Ar/Ar dating: a provenance study of Middle Stone Age obsidian artifacts from Ethiopia

Obsidian sourcing based on geochemistry is widely applied to reconstruct commerce patterns and dissemination of early hominid groups. Due to problems concerning potential intra-source variability or homogeneity of a geological source over large areas, parameters additional to this classical approach are desirable. Here we present the first ⁴⁰Ar/³⁹Ar investigation of Middle Stone Age (MSA) obsidian artifacts (i.e. debitage pieces) for this purpose, as well as of potential geological obsidian sources from Ethiopia. With the present pilot study we demonstrate that ⁴⁰Ar/³⁹Ar geochronology represents a reliable and powerful tool for archaeological provenance studies complementary to the geochemical approach and more recently applied techniques like fission track counting or Mössbauer spectroscopy. Two independent sets of debitage and potential source rock samples were dated by the ⁴⁰Ar/³⁹Ar method. Debitage pieces from the Kulkuletti excavation site and obsidian samples from the nearby obsidian outcrop Worja (central Ethiopia) exhibit basically identical age ranges as well as similar Ca/K and Cl/K ratios, supporting the debitage/source rock relationship previously inferred on geochemical grounds. A second small set of geochemically characterized debitage samples from the Porc Epic cave and potential source rocks from an obsidian outcrop at Kone (Eastern Ethiopia) however have different ⁴⁰Ar/³⁹Ar ages and Ca/K and Cl/K ratios. These results contradict the previous conclusion about a debitage/source rock relationship of the Porc Epic and Kone samples made on the basis of geochemistry [A. Negash, M.S. Shackley, Archaeometry 48 (2006) 1]. Additional sampling at the Kone outcrop as well as of other obsidian occurrences in the greater area is needed to unambiguously pinpoint the origin of these obsidian tools.     

Measuring prehistoric mobility strategies based on obsidian geochemical and technological signatures in the Owens Valley,California

We compare the organization of obsidian flaked stone technologies in two different time periods at CA-INY-30, a village site in southern Owens Valley, eastern California. Previous archaeological studies suggest a reorganization in settlement patterns between the Newberry (ca. 3500–1500 BP) and Marana (ca. 650-contact) periods, from a highly mobile to a more residentially sedentary one. New geochemical data, based on laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) analyses of obsidian artifacts associated with discrete house floors, support this basic settlement model, but reveal new detail in how people moved across the landscape and accessed, extracted, reduced and used obsidian resources. In the earlier Newberry period, there is no relationship between flake size and distance-to-source, and the falloff curve relating frequency of obsidian against distance is more gradual, as expected, but contrary to our expectations, source diversity is not higher. These factors suggest extremely high mobility, but also selective extraction of particular sources. Newberry obsidian may have been acquired by groups of hunters who embedded quarrying within long-distance trips to distant hunting grounds, and subsequently transported bifacial cores to base camps. By contrast, Marana patterns show strong relationships between flake size and distance from source and steeper fall-off curves, suggesting groups acquired their obsidian primarily from closer sources, likely via exchange networks. At the same time, geochemical diversity, especially among smaller resharpening flakes, is higher in the Marana period, highlighting the wide-ranging conveyance systems through which obsidian moved.     

Macusani obsidian from southern Peru: A characterization of its elemental composition with a demonstration of its ancient use

Transparent obsidian artifacts have been reported for the northern Lake Titicaca Basin. Based on instrumental neutron activation analysis (INAA) of these artifacts a distinct chemical group was identified. Yet, the location of the source of transparent obsidian in the southern Andes remained unreported in the archaeological literature. This paper reports on the chemical composition and geographic location of a source of transparent obsidian from the Macusani region of Peru. Through the use of INAA and portable X-ray fluorescence (PXRF) we demonstrate that Macusani obsidian or macusanite comprises (at least) two chemical groups. One of these groups was used for making artifacts during the Archaic Period. Artifacts made of this obsidian were found more than 120 km from the source and yet, one-third of the obsidian artifacts encountered at Macusani were from the non-local source of Chivay which is 215 km to the southwest.     

Cultural interactions during the Ubaid and Halaf periods: Tell Kurdu (Amuq Valley,Turkey) obsidian sourcing

In order to decipher cultural influences, the inter-regional contacts of the Tell Kurdu settlement have been investigated through obsidian sourcing for the Halaf and Ubaid phases (c. 5700–4300 cal. BC). The chemical composition of nine artifacts from three archaeological levels of the site have been determined and compared to source data obtained in our laboratory or available in the literature. Trace and major element analyses were performed respectively by inductively coupled plasma - mass spectrometry (ICP-MS) and atomic emission spectrometry (ICP-AES). The results assignments point out five distinct sources which highlight northwestward and eastward connections. Besides the “traditional” procurement areas (Göllü Dag and Nemrut Dag massifs; Bingöl region), the development of new exploitation centers (northeast Anatolia and northeast Van lake) is noteworthy. These results of obsidian provenances are compared to those of other raw materials and production originating from distant areas, in order to outline Tell Kurdu trade networks during the Halaf and Ubaid periods.     

Validity of “off-the-shelf” handheld portable XRF for sourcing Near Eastern obsidian chip debris

Handheld portable XRF (HHpXRF) has received considerable recent attention in archaeology, especially for obsidian sourcing. Published studies largely suggest a high potential for success. HHpXRF, though, has been met with debate and scepticism. Concerns fall into three categories: (1) low accuracy and precision, (2) data correction schemes and calibration, and (3) ignorance of fundamental XRF issues such as specimen size limits and morphology effects. The result is that archaeological interpretations in HHpXRF-based studies are cast into doubt. Should interpretations be believed if authors did not follow the perceived best practices? To address such questions, the validity of HHpXRF for Near Eastern obsidian sourcing was tested under deliberately “sub-optimal” conditions. Irregular obsidian debitage near the minimum size limits was sourced with a success rate of 94% (based on A-rank matches) to 100% (based on A- and B-rank matches) even under conditions chosen to mimic “off-the-shelf” operation.     

New investigations of the Göllüdağ obsidian lava flows system: a multi-disciplinary approach

The Göllüda? obsidian lava flow system is relatively complex. More than ten different obsidian outcrops and knapping workshops have been identified around this volcano. Their importance for long and short distances obsidian supply has already been demonstrated.One of the main problem encountered when studying the Göllüda? obsidian flows, is the great chemical similarity of some of them. The use of the geochemical approach to solve the problems of obsidian trade around the Göllüda? is therefore insufficient. A multi-disciplinary program joining archaeology, geochemistry and geomorphology, was thus started to understand the relationships between the different obsidian flows and to draw the pattern of the Göllüda? obsidian trade.Our archaeological and geomorphologic approach will help us to understand which obsidian outcrops were available during the Palaeolithic and Neolithic periods.Also our geomorphologic approach, linked to intensive geochemical analyses, will help us to understand the spatial variability of the geochemistry of the obsidian outcrops. Lithic technology will also give information about the different knapping methods used at the workshops.     

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.     

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.     

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.