Late Pleistocene and Holocene Sea-Level Highstands in Northern Australia

Abstract

Late Pleistocene and Holocene sea-levels along sections of the northern Australian coastline were significantly higher than present. An in situ, raised coral reef on the western shore of the Gulf of Carpentaria returned ¹⁴C ages of 26 ka BP. and 30 ka BP. The results of independent studies of Late Quaternary environments, both here and nearby and the fact that these corals have undergone extensive calcite recrystallisation suggest that this raised fossil reef is of Last Interglacial age or older. Several raised beach deposits sitting up to 2.5 m above high tide level near Darwin returned ¹⁴C ages ranging between 2.05-3.39 ka BP. The relative heights of these deposits and the raised in situ coral reef suggest: firstly, that sea-levels may not have fallen progressively from the mid-Holocene everywhere in this region, and secondly that the northern margin of the Australian continent may not be subsiding as rapidly as previously thought.