Synergetic influence of water masses and Kangaroo Island barrier on foraminiferal distribution, Lincoln and Lacepede shelves, South Australia: A synthesis

Abstract

The mid-latitude, cool-water, high-energy Lincoln and Lacepede Shelves along the southern Australian margin are covered with mixed Holocene and Pleistocene sediments. Foraminiferal specimens of Recent and Pleistocene age from dredge samples are strongly mixed. Eight assemblages in two major groups A and B were recognised from the inner shelf to the upper slope, and they appear to be depth-related. However, some are typical of localised environments such as an upwelling zone (assemblage A2) or areas strongly affected by a high accumulation of relict specimens indicative of previous lagoonal deposition (assemblages A3 and A4). Sediment starvation due to strong wave abrasion is largely responsible for the preservation of this mixed biofacies. The interaction between shelf waters (the Great Australian Bight Current), waters from the Spencer and St. Vincent Gulfs, oceanic waters and waters from the River Murray, is suggested as the main factor controlling the overall distribution pattern of foraminifera. A war...