Holocene stratigraphic and morphological evolution of the Wandandian Creek delta,St Georges Basin,New South Wales |
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Authors: | C A Hopley B G Jones |
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Institution: | 1. School of Earth &2. Environmental Sciences , University of Wollongong , NSW, 2522, Australia cah01@uow.edu.au;4. Environmental Sciences , University of Wollongong , NSW, 2522, Australia |
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Abstract: | Subaerial exposure beside the Wandandian Creek channel during the last glacial maximum led to the development of red and orange mottling and, in some areas, produced a palaeosol over the Pleistocene land surface. Incision of the palaeo-Wandandian Creek, during the Late Pleistocene, formed a relatively deep steep-sided channel partially infilled with medium-grained fluvial sand. This palaeovalley became drowned as the post-glacial marine transgression impounded the western portion of St Georges Basin and the basal prodelta/lagoonal mud facies was deposited from ca 7 ka. The Wandandian Creek delta prograded down the palaeovalley and reached the study area ~3500 – 4000 years ago with the deposition of delta-front sandy silt and the overlying prograded sand facies. The subaerial portion of the delta is characterised by well-developed floodplains, levees, mouth bars and backswamps. Dredging in Wandandian Creek and land clearing for rural and urban development have had little long-term effect on the growth and morphology of Wandandian Creek delta. |
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Keywords: | amino acid racemisation delta estuarine lagoon Holocene marine transgression palaeovalley |
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