Spatial and Temporal Variability in Chert Exploitation on Santa Cruz Island, California

Abstract

Chert outcrops on eastern Santa Cruz Island were of vital importance to the inhabitants of the Santa Barbara Channel region because of their comparatively limited availablity elsewhere on the California Channel Islands. Temporally diagnostic artifacts and radiocarbon dates from associated shell middens suggest that chert quarries were exploited throughout the Holocene. The importance of these quarries has been well documented in regard to microlith production as part of the shell bead industry during the late Holocene. However, relatively little is known about local chert tool manufacture and exchange in earlier times. Systematic documentation of 26 known chert quarries, and sampling at associated shell middens on eastern Santa Cruz Island has resulted in the identification of significant spatial variability in chert exploitation through time. Whereas chert quarrying during the middle Holocene appears to have been opportunistic and dispersed throughout the landscape, comparable activities during the late Holocene became increasingly circumscribed as microlith production was intensified. These trends in chert procurement are interpreted in the context of temporal changes in subsistence, tool manufacture, and residential mobility on the northern Channel Islands, and have broad implications for spatial and temporal patterning in prehistoric lithic exploitation.