The potential for discovery of new submerged archaeological sites near the Dampier Archipelago, Western Australia

Abstract

The islands of the Dampier Archipelago preserve a probable 30,000 year archaeological record that reflects the change from a continental to an island environment following post-glacial sea-level rise. The geomorphological history of the Dampier Archipelago region in combination with preliminary hydrodynamic modelling of past tidal regimes provides the basis for a new model of how the shelf landscape may have developed between the Last Glacial Maximum (c. 20 ka BP), through the Holocene marine transgression and up to the present day. Using first-order geomorphological principles, an assessment is made of the key Late Pleistocene and Holocene sediment bodies that may preserve archaeological deposits.We show that archaeology is most likely to be present in deposits associated with the early phases of inundation of the Dampier Archipelago, dating from around 9–7 ka BP. At this time relative sea levels were around −30 m to –15 m, which was when coastal configuration was complex and the variety and scale of intertidal and shallow sub-tidal environments wide. In contrast, we anticipate that coastal archaeology older than ∼12 ka BP, when the post-glacial sea levels were below ∼50 m, will have been exposed to a phase of faster tidal currents on the continental shelf, and hence eroded or poorly preserved. Our study aims to improve prospection for and later management of the as yet-unknown submerged elements of West Australia's rich archaeological heritage.