Reconnaissance Thermoluminescence Dating of Northern Australian Coastal Dune Systems

Abstract

Quaternary lithostratigraphic units in coastal dunes have been dated at three locations in northern Australia, Cobourg Peninsula, Shelburne Bay, and Cape Flattery, by both radiocarbon dating of shell and organic carbon and thermoluminescence (TL) sediment dating. Both coarse fraction and fine fraction TL methods were used. Seventeen TL dates were measured. None of the TL dates contradict the ages given by radiocarbon. Where multiple TL dates were taken from a unit, they overlap within 2 standard deviation giving added confidence in the results. A phase of dune emplacement during the late Holocene (ca. 2700-1800 yr B.P.) was identified in two of the dune-fields, an early Holocene phase of dune emplacement (ca. 8600-7500 yr B.P.) in two of the dune-fields, and a late Pleistocene episode (ca. 24,000–17,000 yr B.P.) in both the Cape York dunefields. Three older units gave dates of about 29,000, 81,000, and 171,000 yr B.P., but these must be treated with caution.