The Quaternary geomorphological evolution of the River Murray mouth and lakes region, southern Australia

This thesis examines the Quaternary geomorphological evolution of the River Murray Mouth region of southern Australia in the context of increasing aridity and fluctuations in eustatic sea level and climate. The region is located at the northern margin of the Coorong Coastal Plain, which preserves a long terrestrial record of Quaternary sea-level highstands within the Bridgewater Formation, a sedimentary succession of coastal carbonate aeolianites with associated beach and back-barrier lagoon facies. The stratigraphic record within the study area has been obscured by long term regional subsidence due to its location adjacent to the uplifting Mount Lofty Ranges, erosion by the River Murray and the dunefields of siliceous Molineaux Sands deposited under continental conditions during periods of glacially low sea levels. Unravelling the depositional record within this region assists in understanding localised variations in the sea-level record, the position of the River Murray during eustatic sealevel fluctuations and the dichotomy of sedimentary successions between the terrestrial, arid climates of glacial periods and marginal marine, wetter climates of interglacial periods.