Large parts of central Australia are currently desert or semi-arid areas that receive less than 150 mm of mean annual precipitation and suffer from intensive evaporation. Yet, witnesses of much wetter periods are plentiful in the central and southern part of the Australian continent and include extensive lake, river and alluvial fan deposits. Lake Eyre is the world’s largest dry lake and maybe the most notable example of Australia’s changing climatic conditions. Repeated filling events during the Late Pleistocene and Holocene have been documented for Lake Eyre and the adjacent playa lakes that surround the Flinders Ranges in Southern Australia. During the wettest periods of the last glacial cycle these lakes formed an impressive mega-lake system and were directly linked to alluvial fans that are flanking the Flinders Ranges and ephemeral rivers that supplied water from the tropical north. In combination these landscape features form unique sedimentary repositories that hold important clues for the Australian continent regarding palaeohydrology, environmental change and climatic forcing.
In this collaboration we investigate modern and Holocene palaeoshorlines from selected sites at Lake Eyre North and alluvial fan deposits from the Flinders Ranges (Brachina Gorge fan). Using optically stimulated luminescence (OSL) dating, geomorphological mapping and sedimentary logging will allow us to construct a detailed chronostratigraphic framework for these sites. For strongly bioturbated sediments single-grain OSL dating will play a key-role to further improve the precision on our OSL ages and thus refine our palaeohydrological interpretations.
Collaboration between Michael Meyer and Tim Cohen, Jan-Hendrik May & Gerald Nanson (U. Wollongong, Australia). Further collaborators: Colin Murray-Wallace & Brian Jones (U. Wollongong, Australia).