New quartz SAR-OSL ages from the stranded beach dune sequence in south-east South Australia

A sequence of stranded coastal barriers in south-east South Australia preserves a record of sea-level variations over the past 800 ka. Huntley et al. (Quat. Sci. Rev. 12 (1993a) 1; Quat. Sci. Rev. 13 (1994a) 201) attempted to test thermoluminescence (TL) dating methods and found good agreement between quartz TL ages with independent ages for these dunes. We investigate the accuracy of the single-aliquot regenerative-dose (SAR) procedure (Radiat. Meas. 32 (2000) 57) over an extended age range of 0-250 ka, by comparing SAR-OSL ages determined on quartz extracts from these dunes with the existing chronology. We show that Robe II range is similar to60ka. and that Robe III is 100 ka old. Not surprisingly, the OSL ages increase monotonically from the Robe II range to the West Naracoorte range. For the younger dunes (<240 ka), the SAR-OSL ages agree with the expected ages within 1sigma errors, whereas for the older dunes the SAR ages are consistent with independent ages within 2sigma error limits. We consider these results to be very promising, and lend support to the large number of quartz SAR-OSL ages being presented in the literature, where such comparisons with independent chronology are not usually possible. (C) 2003 Elsevier Science Ltd. All rights reserved.