on these sites' relationships with the monumental center of Chavin de Huantar, Peru. New research, however, has demonstrated that Chavin's architectural sequence is much different and more complex than previously believed, and that its monumental construction concluded between 900 - 780 B.C., the time previously thought to mark the site's beginning. This represents a major shift in Chavin chronology that significantly impacts understanding of Andean formative social development. Chavin's few dates are now associated with the final monumental stage and later periods of the site's long construction sequence. Consequently, the time depth represented by the undated, complex monumental stages prior to this suggests that the sequence extends much farther back in time than previously believed. This increased time-depth would dramatically change archaeologist's understanding of the Andean formative period. Additionally, many other formative sites are sparsely dated, making inter-site comparisons problematic. Dating of the architecture at Chavin and other formative sites is thus a fundamental priority for accurately understanding the chronology and social development of this period. The objective of this research is therefore to test new ways to directly date architecture, in order to establish the absolute chronology of Chavin and, in the future, of other formative sites lacking sufficient dates. Traditionally, archaeological dating of prehistoric architecture relies on collecting radiocarbon samples from cultural deposits within or surrounding buildings; predictably, however, direct associations between such samples and the actual construction of buildings can be tenuous. The goal of this research, in contrast, is to directly date the construction materials of the buildings themselves. Two simultaneous projects to test novel dating methods at Chavin will be carried out. The first will be a pilot project to assess the feasibility of using optically stimulated luminescence (OSL) to date the incorporation of plaster, mortar, and sandstone and quartzite stone blocks into Chavin's buildings. The second project will assess the feasibility of applying radiocarbon dating to the mortar and plaster at Chavin in particular and to architecture in the formative north-central Andes in general. This work is part of a larger collaborative project at Chavin ongoing since 1994. It will take a minimally invasive approach, holding at its core a fundamental concern to impact the preservation of this important site as little as possible, through the collection of extremely small samples. Team members include experts in luminescence dating, radiocarbon dating, and Chavin's architectural sequence. They will develop methods to collect samples in novel contexts. Work will include assessing the appropriateness of Chavin's building materials for dating using OSL and radiocarbon dating; systematically searching for and collecting samples for each method in key areas from each of the site's fifteen phases within its five larger construction stages; using digital and laser technology to record sample data; and coordinating with ongoing excavations at Chavin. If successful, this research will produce new field methods for use in future projects dating similar architectural materials. If successful, this work will also contribute significantly to anthropology by, first, establishing OSL as a method for directly dating prehistoric building materials, with potential for wide application; second, establishing direct radiocarbon dating of architecture as a method suitable in the north-central Andes; and third, establishing the absolute chronology of Chavin's architecture, with profound implications for understanding formative social development. This work will thus create a methodological, chronological, and theoretical foundation for future comparative study of architectural sequence and chronology across many formative Andean centers. The broader impacts of this research include, first, integrating research and education through graduate student training and participation in the project, and through the collaboration of specialists to address a significant archaeological problem; second, broader participation of diverse team members in NSF programs; third, contribution to a larger, international collaborative project; and finally, the broad dissemination of results through conferences, journals, books, and websites as well as teaching.
