LATE PLEISTOCENE MARINE CHRONOLOGY OF THE GIPPSLAND LAKES REGION, AUSTRALIA

Thermoluminescence dating is used to define the chronology of the coas tal barriers of the Gippsland Lakes region, Australia. The area eviden ces a long history of marine deposition extending back to the Middle P leistocene, However, the majority of Pleistocene barriers have formed since the Last Interglacial during two phases at 54 to 72 ka and 40 to 48 ka corresponding to interstadials. A third phase, with dates aroun d the Last Glacial, appears to represent rapid shoreward movement of L ate Pleistocene sediment From the shelf during the Holacene. Barriers have developed in an en echelon fashion seaward as the region has been uplifted tectonically. Some Late Pleistocene marine deposits reach el evations of 40 m above present: sea level. These elevations imply rate s of tectonic uplift exceeding 80 mm per thousand years, rates that ma y have increased toward the present Deposits are preserved as isolated remnants because of subsequent fluvial and marine erosion. Both erosi on and rebuilding may have occurred under the influence of tsunami ori ginating from the south Tasman Sea; The unique distribution and preser vation of recurrent interstadial barriers in the Gippsland Lakes regio n reflect rapid uplift, abundant sand supplies, and the proximity of t his coast to sources for tsunami.