Late Quaternary mega-lakes of central Australia: varying moisture sources and increased continental aridity.
2010 (English)In: EOS Transactions, American Geophysical Union, PP31B-1624. San Francisco, USA, Dec. 2010., Washington DC: American Geophysical Union , 2010Conference paper (Other academic)
Optically stimulated (OSL) and thermoluminescence (TL) ages from relict shorelines, along with accelerator mass spectrometer (AMS) 14C ages from freshwater molluscs reveal a record of mega-lake phases over the late Quaternary for Lake Mega-Frome, situated in the arid zone of South Australia. Additional lacustrine, palynological and terrestrial proxies are used to reconstruct a record that extends as far back as 105 ka and demonstrates that Mega-Frome was last joined to the adjacent mega-Eyre at 50 - 47 ka forming the largest palaeolake on the Australian continent. This time interval for hydrological decline coincides with the arrival of humans on the Australian continent and the demise of the mega-fauna. Since then, Mega-Frome has filled independently at 33 - 31 ka (Heinrich event 3) and at the termination of the Last Glacial Maximum (LGM) to depths far in excess of those seen today (up to 15 - 20 times modern lake volumes). Further evidence of subsequent lake-filling episodes is recorded immediately prior to the Younger Dryas, the mid Holocene and during the medieval climatic anomaly. We present evidence for multiple moisture sources over this time period with lake phases being driven by either an enhanced Southern Ocean circulation or an enhanced tropical moisture source or a combination of both. We show however, that southern hemisphere summer insolation maxima (monsoon proxy) is a poor predictor for past palaeo-lake filling episodes. This is the first palaeohydrological record for a large area of southern semi-arid Australia indicating a progressive shift to more arid conditions throughout the last glacial cycle
Place, publisher, year, edition, pages
Washington DC: American Geophysical Union , 2010.
, EOS Transactions, American Geophysical Union, PP31B-1624
palaeolakes, palaeoshorelines, Quaternary, luminescence, stratigraphy, arid zone
Research subject Physical Geography
IdentifiersURN: urn:nbn:se:su:diva-54236OAI: oai:DiVA.org:su-54236DiVA: diva2:392406
American Geophysical Union Fall Meeting