GEOARCHAEOLOGY, PALEOGEOGRAPHY, AND THE SEARCH FOR PALEOINDIAN SITES IN THE HIGH ANDES OF SOUTHERN PERU

This interdisciplinary project examines links between Late Glacial environmental changes and the initial human settlement of the high Andes of southern Peru. The well-dated archaeological site Quebrada Jaguay (QJ-280) is unique among New World Paleoindian coastal sites in that it contains lithic materials from interior zones, and the specific provenance of QJ-280's most exotic material – Alca obsidian – is known with considerable precision. This QJ-280-Alca connection has provided an opportunity for locating additional Paleoindian sites linked to QJ-280 in the intervening ~150 km between the two locales.

Incorporating data from geoarchaeological mapping and geochemical characterization of toolstone source deposits, glacial geologic study of highland ice caps, and exploration of potential coast-highland routes, we have modeled a GIS predictive least-cost corridor linking QJ-280 with resources in interior ecozones. Extensive archaeological survey of the corridor has located a series of early highland sites with coastal lithic materials, many of which surround the extensive high-altitude Pucuncho bog. Our discovery of an obsidian Fishtail projectile point base at ~4,360 m on the west side of Pucuncho proves a Paleoindian exploration of this area between 10,800-10,200 14C B.P. (~12,800-11,700 cal B.P.), constituting the highest Late Glacial-age human evidence in the world.

Preliminary reconstructions of glaciers on Coropuna (~6,400 m), a glaciated volcano adjacent to the Pucuncho bog and Alca obsidian deposits, suggest that snowlines in the highlands were as much as 400 m lower during the Late Glacial period than today, corresponding to a temperature depression of ~2.6-3ºC. The Pucuncho bog would have been below the limit of permafrost and might therefore have been a productive habitat for Paleoindian people. We plan paleoecological investigations of the Pucuncho bog and archaeological excavations of surrounding rockshelter sites to shed light on the timing and processes of Late Glacial environmental changes and initial human exploration of the high Andes.