Landscape evolution and human settlement patterns on Ofu Island, Manu'a group, American Samoa

Abstract

This study summarizes the impacts of geomorphological processes on human settlement strategies on the island of Ofu in the Samoan Archipelago from island colonization to permanent settlement in the interior uplands (c. 2700-900 b.p.). Previous archaeological research on Ofu has documented a dynamic coastal landscape at one location, To’aga, on the southern coast. Using a new geoarchaeological data set, our study extends this assessment to a site on the western coast of the island. We conclude that although the sequence of coastal evolution is broadly consistent between the two areas there are also differences indicating that island-wide coastal evolution did not progress everywhere at the same rate. Using this data set, we record changes in human settlement patterns temporally correlated with coastal progradation-perhaps related to continued drawdown from the mid-Holocene sea-level highstand-and sediment aggradation. We suggest that coastal landscape change on Ofu may have been one factor in the expansion of the terrestrial component of the human subsistence base and the more intensive use of the interior uplands of the island. The timing of this settlement change was slightly earlier than elsewhere in the region, demonstrating the variability of human response to regional-scale environmental changes