The last interglacial shoreline in Australia — A review

Marginal marine strata of last interglacial age occur in a range of morphostratigraphic settings around the Australian coastline. The lithofacies are similar to their Holocene equivalents but are partly lithified, elevated and laterally displaced inland. Uranium-series ages for corals and molluscs from widely separated localities around the Australian coastline are generally in accord with the accepted age for Oxygen Isotope Substage 5e (125,000 ± 10,000 BP), the value generally accepted for the last interglacial maximum. Amino acid racemisation has principally been applied to correlation of sequences with benchmark sites dated by the uranium-series method. Elevations of preserved last interglacial shorelines do not support the notion that Australia is a stable continent. Significant neotectonic anomalies include Cape Cuvier (+10.5 m), Fleurieu Peninsula (+6 m), the Coorong Coastal Plain (+10 m) and Tasmania (+32 m), each indicating contrasting degrees of local uplift. The Tasmanian sequences are the highest occurrence on the Australian continent and have been attributed to uplift as a result of mantle hotspot processes. With the exception of these tectonically uplifted sites, the height of the last interglacial sea surface around the Australian coastline is consistently below the 6 m level globally attributed to this high sea level stand. In Australia, the most consistent datum is from western Eyre Peninsula where a level 2 m above present mean sea level is ubiquitous. The more southerly limit of coral growth and wider distribution of subtropical molluscan fauna are in accordance with warmer ocean waters during Substage 5e (approximately 2°C). The extent of racemisation in molluscan fossils from southern Australia also excludes the possibility of a more equable latitudinal distribution of MAT during Substage 5e.