Contemporary benthic foraminifera in Gulf St Vincent, South Australia, and a refined Late Pleistocene sea‐level history

Publisher Website
Google Scholar
Abstract
Benthic foraminifera are abundant in surficial sediment of Gulf St Vincent and the distribution of many species is related to water depth. For example, Nubecularia lucifuga is most abundant in shallow northern waters while Ammobaculites reophaciformis is more common in deeper southern parts of the gulf. Elphidium crispum, a shallow‐water species, and E. macelliforme, favouring deeper water, provide a useful numerical ratio. Their logarithmic relative abundance in the sediment size fraction 0.50–0.25 mm correlates closely with water depth, particularly for southern Gulf St Vincent. Vibrocore SV23 recovered an undisturbed section of Quaternary strata from one of the deepest parts (40 m) of the gulf. Late Pleistocene sediment (oxygen isotope stage 3) was in turn overlain by rapidly deposited lacustrine and restricted marginal marine sediment before development of more open Holocene marine conditions. Using the Elphidium ratios and other supporting foraminiferal data on a framework of 14C dates, a palaeosea‐level curve was calculated from SV23. Changes in sea‐level so derived for the period 45–30 ka bp agree closely with those previously calculated for Gulf St Vincent and can be correlated with those determined from studies of Huon Peninsula coral reef terraces. For this time‐interval, southern Australian palaeosea‐levels of ‐30 to ‐27 m are indicated from the work reported here.