SORT : Stanford Obsidian Research Team

Ours is a small research group dedicated to the trace elemental characterization of archaeological obsidians via the instrumental facilities of the department of Geological and Environmental Sciences at Stanford University. The group is part of a wider network of labs and on-going archaeometric projects detailing the exchange and use of obsidians in the prehistoric Old and New Worlds, via the research of Tristan Carter, Lecturer in the Department of Cultural and Social Anthropology. The work at Stanford has an avowed inter-disciplinary approach, involving researchers from the Departments of Anthropological Sciences, Cultural and Social Anthropology, plus Geological and Environmental Sciences. Moreover, it offers an important context for the development of undergraduate research. While the two projects that form the core of the first SORT research are designed carefully to be discretely bounded studies that are aimed to be completed within an academic year, both represent springboards for future analyses that we hope will involve more undergraduates in the future.

The starting point of our research is two sets of material from excavations in Peru and Turkey, both of which are directed by current Stanford Faculty.

Çatalhöyük-West (Turkey)
The world famous prehistoric site in central Anatolia comprises two artificial mounds (or tells) that rise above the Konya Plain. The larger, earlier and better known mound is Çatalhöyük-East, whose occupation spans the Aceramic Neolithic to Early Neolithic (c. 7400-6200 cal BC). This large village appears then to have been abandoned, with the inhabitants shifting a few hundred meters away, across the Carsamba River, to establish a new settlement at Çatalhöyük-West. Recent radiocarbon determinations suggest that this village was occupied between c. 6000 – 5500 cal BC, or the Early Chalcolithic I-II [ECI-II] period in archaeological terms (the earliest levels have yet to be exposed and dated, hence the apparent hiatus between the two mounds).

For both communities the primary raw material employed to manufacture their flaked implements was obsidian (usually >90% of any assemblage), despite the fact that the nearest sources of this volcanic glass are located 120 miles to the north-east, in the region of Cappadocia. It has long been argued that this was an extremely valuable resource to Çatalhöyük, not only with regard to its functional capabilities and daily household use, but also in terms of the community’s (alleged) role in its long-distance exchange and its symbolic properties.
In 1999 a major characterization program was initiated dedicated to sourcing Çatalhöyük’s obsidian through time. This work, under the directorship of Carter, involves a number of different laboratories and instrumental techniques, specifically: CNRS / Grenoble (ICP-MS/AES), CNRS / Bordeaux (PIXE, SEM-EDS), University of Aberystwyth (LA-ICP-MS), University of California, Berkeley (XRF-EDS). Some 277 samples have now been analyzed within this project, of which the results from 135 are currently in press, while the other data sets are being prepared for publication. The artifacts characterized have derived mainly from Çatalhöyük-East, spanning the basal Aceramic Neolithic (Level Pre-XII.D) to upper Early Neolithic (Level III) occupation layers. Thus far only seven pieces of obsidian from Çatalhöyük-West have been analyzed, it is the aim of our new work at Stanford to investigate further the material from the Chalcolithic period.
The 49 artifacts that form the basis of Stanford data-set come from the excavation of a mudbrick structure (Building 25) and various refuse pits whose contents span the ECI-II. The sampling strategy was designed to select a representative range of raw materials in terms of the variations in color, banding, texture and translucency represented within the assemblages under consideration. It also attempted to select items that were diagnostic of the various knapping traditions, or industries documented in the Çatalhöyük-West material.
The significance of this project is manifold. Firstly it will increase the number of samples from this part of the site so that we may have a more confident notion of which obsidian(s) were being procured by the EC community and – hopefully – in which form(s) these glasses were circulating. Secondly, it will increase the time depth represented within our characterization study, allowing us to appreciate the long-term history of obsidian exploitation at Çatalhöyük. Thirdly, by examining material from Chalcolithic levels we can start to address the question of what was occurring at the quarries at this time, a period for which we have very little information. Fourthly, by focusing on Early Chalcolithic data we will be helping to redress a research bias in Anatolian / Near Eastern / Cypriot obsidian characterization studies, namely the overwhelming focus on material from Neolithic contexts.

Previous results
The seven obsidian artifacts analyzed previously from Çatalhöyük-West were provenanced to the southern Cappadocian volcanoes of Göllü Dag-east (n=3) and Nenezi Dag (n=4). These appear to have been Çatalhöyük’s primary sources throughout its occupation, albeit with important differences in the history and form of their use (e.g. Figure 1).

Figure 1: Combined results of the 235 artifacts thus far analyzed from Çatalhöyük, by level (one sample assigned to Acigöl West).

Project personnel: Tristan CARTER (CASA), Rachel KING (undergrad), Guangchao LI (GES) and Gail MAHOOD (GES).

Chavín de Huántar (Peru)

The UNESCO World Heritage site of Chavín de Huántar is located in the north-central sierra of Peru, along a natural access route between the coast and eastern tropics.

The ceremonial center sits at 3150 m elevation in a high valley on the eastern side of Peru’s Cordillera Blanca, at the confluence of the Mosna and Wacheqsa rivers. The site, a complex of stone-faced platform mounds, terraces, and sunken plazas, dates to roughly 1500-500 BC. The platform mounds are built over a complex and interconnected accretion of subsurface galleries that have been home to some of the most spectacular archaeological finds at Chavín and have figured prominently in reconstructions of ceremonial practice at the site.
One of only a handful of monumental highland sites from this early period, Chavín has been the subject of interpretive extremes. These vary about two major axes: the nature of Chavín’s apparently pan-Andean influence and the interpretation of its development. Along the first axis, Chavín has been described as the center of Peru’s autochthonous mother culture at one extreme and suggested as a relatively late and synthetic center of cultural developments derived from the coast at the other. Along the second axis, Chavín has been variously interpreted as a center of coast-jungle cultural synthesis, a pilgrimage and cult center with ideological sway over much of the Central Andes, and a locus of the development of authority and social complexity.

Given the historic research interest in the nature of Chavín’s relationship to the rest of Peru (i.e. as source, or perhaps simply exemplar, of the first pan-regional ideological system to develop in Peru), the source characterization of obsidians found at the site is a natural focus of further research. The extent and nature of Chavín’s contacts with contemporary ceremonial centers, both in the highlands and on the coast, was certainly linked to the circulation of valuable materials like obsidian, which likely played a significant ceremonial as well as economic role. Excavations at Chavín have generally found obsidian to be widely present but never abundant, likely reflecting the difficulty in obtaining an exotic raw material from nearly 600 air km away.

Previous research by Burger found the overwhelming majority of obsidian samples from Chavín to come from the Quispisisa obsidian source, some 580 km to the south. The last decade of excavation at the site has provided an assemblage from more diverse and better-dated contexts. Internal variation in the use and ability to procure obsidian remains under-examined, and it remains to test the current presumption that Chavín’s obsidian was overwhelmingly from the Quispisisa source. Ultimately, such research will fit into an emerging understanding of the patterns of obsidian procurement and circulation in the Formative Period Andes.

Project personnel: Tristan CARTER (CASA), Dan CONTRERAS (AnthSci), Guangchao LI (GES), Gail MAHOOD (GES), Kristin NADO (AnthSci undergrad), John WOLFF (AnthSci).

Undergraduate Training
A central component of SORT’s aims are the inclusion of undergraduates within the project from the outset, to be involved in selecting the artifacts for analysis, processing the samples, interpreting the data and to contextualize the results through more general research upon the area and period under consideration. It is envisaged that the training will take the form of formal class time and dedicated research supervision. With regard to this year’s research we have established the following structure and timetable:

(i) Student to take the Geoarchaeology class offered in the winter term taught by Gail Mahood and Sid Carter (Arch/GES 186).
(ii) Student to register with Gail Mahood for weekly directed undergraduate research through winter and spring (GES 192) – units to be decided.
(iii) Student to meet weekly on informal (no unit accredited) meeting with Tristan Carter to discuss archaeological context.