The South Australian Sea

Abstract

The seascape of elongate gulfs that penetrate into the continental interior, the corridor of Investigator Strait, the sweeping arc of Lacepede (Encounter) Bay, and the bedrock of Kangaroo Island together generate a wide variety of neritic depositional environments. The cliffed coast around Kangaroo Island and Yorke Peninsula is mostly bedrock, as it is along the southern tip of Fleurieu Peninsula with bays cut into softer Pleistocene Bridgewater calcarenites. The curving sweep of the Lacepede Bay shoreline is a prograding aeolianite coast and high-energy beaches that have undergone Quaternary uplift. It is now series of stranded Pleistocene beach-dune complexes that in some places may stretch back to the late Pliocene. The entrances to Spencer Gulf and Gulf St. Vincent are bounded either by bedrock or by aeolianites whereas the interiors have local low energy tidal flats. There are no rivers delivering any significant siliciclastic sediment in this relatively arid region (Figs. 9.1, 9.2, 9.3).