Coastal dune hydrology and its influence on maritime occupation sites (12–0.2 ka) in a semiarid island, San Miguel, California, USA

Abstract

Maritime occupation sites in upland dune settings (10–150 m elevation mean sea level) in San Miguel Island (37 km2 in size), located 40 km offshore of the south‐central California mainland, were analyzed for reported ages, component types, and distances from paleo‐shorelines around the island’s shelf platform. The occupation sites (dated ~12,200 to 200 cal B.P.) include numerous shell middens and lithic scatters. Some sites contain Paleocoastal stemmed points and chipped stone crescents, the latter believed to be used for hunting waterfowl. What prompted the site occupations in the semiarid dune‐covered coastal bluffs and interior‐plateaus that were located 10–150 m above and 1–4 km distant from age‐correlative paleo‐shorelines? Eolianite dune settings in San Miguel include ephemeral freshwater sources from: (a) vernal pond/wetlands in interior plateaus; (b) gullies or creeks in the dune‐covered bluff slopes; (c) springs exposed in current sea cliffs or canyons; and (d) pond/wetlands barraged by sand ramps on the windward bluff slopes and gully drainages. These freshwater features are proposed to have attracted humans and their hunting, shellfish processing, and plant gathering activities to upland localities, as now preserved above the island’s shelf platform that was submerged by the Holocene marine transgression.