Holocene Paleoshoreline and Paleoenvironmental History of Palau: Implications for Human Settlement

Abstract

ABSTRACT Information from cores into the offshore reefs of Komebail Lagoon and into the coastal fringes of Babeldaob and neighboring islets allows the first well-constrained appraisal of the Holocene paleoshoreline history of Palau. Bulk subsidence of the island group since ∼5 kyr at a rate of ∼0.55 mm/yr is indicated jointly by both the offshore and the onshore datasets. Persistent subsidence of paleoshorelines since the initial human settlement of Palau has implications for the evolution of coastal paleoenvironments and the elevations of early coastal habitation sites with respect to present sea level. Discrepancies between radiocarbon dates for the earliest known archaeological sites and the earliest human impact on island environments in Palau and elsewhere in western Micronesia raise pointed questions about the timing of initial human occupation. Knowledge of the paleoshoreline history of Palau suggests that the disturbance indicators provide a more reliable guide to human arrival than the earliest settlement sites discovered to date.