An extended Last Glacial Maximum in subtropical Australia

A continuous, record encompassing the termination of the Last Glacial cycle (defined here as ca. 30-18 cal. kyr BP) has been developed using multiple proxies (viz. clastic sediment flux, grain size, moisture content, pollen and charcoal) archived in lake sediments from Tortoise Lagoon, North Stradbroke Island, Australia. The record indicates an extended Last Glacial Maximum, with an onset at ca. 30 kyr BP. The presence of rainforest and arboreal taxa for the 30-18 kyr BP period indicate a positive moisture balance, while the presence of the now regionally extinct Asteraceae (Tubuliflorae) and Tubulifloridites pleistocenicus indicate relatively cool temperatures. Total clastic sediment flux and the vegetation assemblage suggest that, at least in subtropical Australia, the Last Glacial Maximum was characterized by two peaks in aridity at ca. 29-26 kyr BP and 24.5-20 kyr BP.