Late pleistocene carbonate dissolution patterns in the Tasman Sea

Present-day lysocline levels are determined for the west and east Tasman Sea according to the proportion of planktonic foraminiferal fragmentation in core-top samples. For the east Tasman Sea, the lysocline level occurs at ~3100 m, whereas in the west Tasman Sea it occurs at -3600 m. Foraminiferal fragmentation patterns in deep-sea holes ODP 828, RC 12-113, DSDP588,591,592,593, E36-23 andE39-75 are not consistent with basin physiography, which brings into question the well-known Atlantic versus Pacific-Indian Ocean dissolution patterns for the Brunhes Chron. Although the corrosive Antarctic Bottom Water condition is the main cause for CaCO 3 dissolution, organic matter flux and its metabolic oxidation in pore waters also has an effect on fragmentation patterns. Parallel trends between the fragmentation, and the planktonic δ 13 C records suggests that both are related and respond to a common cause, namely local surface productivity changes.