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Revisiting the abandoned shorelines of Lake George,Australia: a refined optical dating framework |
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| Authors: | N R Jankowski T J Cohen J Larsen A Larsen J-H May |
| Institution: | 1. Australian Research Council Centre of Excellence for Australian Biodiversity and Heritage, University of Wollongong, Wollongong, NSW, Australia;2. Australian Research Council Centre of Excellence for Australian Biodiversity and Heritage, University of Wollongong, Wollongong, NSW, Australia
GeoQuest Research Centre, School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW, Australia;3. School of Geography, Earth, and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom The Birmingham Institute of Forest Research, University of Birmingham, Birmingham, United Kingdom;4. Soil Geography and Landscape group, Wageningen University, Wageningen, The Netherlands;5. GeoQuest Research Centre, School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, NSW, Australia School of Geography, University of Melbourne, Carlton, VIC, Australia |
| Abstract: | Abandoned shorelines are an important archive used to constrain past fluctuations in the hydrological balance of lakes around the globe. Within Australia, the shorelines preserved at Lake George, NSW, form one of the few shoreline archives in the south-east of the continent that record palaeoenvironmental conditions throughout the late Quaternary. Here, we examined and tested the lake-level record for Lake George constructed in the 1970s by dating a well-preserved shoreline sequence at Luckdale, on the lake's eastern shore, using single-grain optically stimulated luminescence (OSL) dating. Ten stratigraphic units were identified, and these suggest a late Quaternary highstand for Lake George in MIS 3, with fluctuations superimposed upon an overall drying trend throughout MIS 2 and into the present. At Luckdale, the highest four shoreline-associated units were deposited ~13 to 19 m above lake base and date to between 39 ± 2 and 29 ± 1 ka ago. Our study pushes back the timing of maximum lake depth at Lake George to at least MIS 3, rather than MIS 2. The overall drying trend is supported by similar reductions in both Riverine Plain fluvial activity and other associated lake-level records from within the Murray basin. |
| Keywords: | Australia Lake George Last Glacial Maximum OSL Shoreline |