CADMIUM AND δ13C PALEOCHEMICAL OCEAN DISTRIBUTIONS DURING THE STAGE 2 GLACIAL MAXIMUM

Abstract

Changes in heat and salt transport by ocean currents have been implicated in ice age climate cycles (Weyl 1 968, Newell 1 974, Broecker et al 1 990b). In addition to the direct physical effects of the ocean on climate, the ocean carbon system controls atmospheric CO2, and the CO2 fluctuations documented in ice core bubbles (Barnola et a1 1 987, Neftel et a1 1 988) are thought to be a significant factor in climate oscillations (Hansen et al 1 984). Dramatic changes in oceanic circulation patterns and carbon system chemistry have occurred during the Late Quaternary glacial/interglacial global climate cycles (Boyle & Keigwin 1 982, Curry & Lohmann 1 983, Shackleton & Pisias 1 984, Boyle & Keigwin 1 987, Duplessy et al 1 988, Curry et al 1 988, Broecker et al I 990a). These changes in the ocean system may be significant driving forces in the progression of ice age CO2 cycles (Toggweiler & Sarmiento 1 985, Ennever & McElroy 1 985, Wenk & Siegenthaler 1 985, Boyle 1 988a,b, Broecker & Peng 1 990). The oceanic distributions of c513C, Cd, and other carbon-system-linked properties are controlled by the interaction between biological uptake and decomposition with the general circulation of the ocean. Because records of past oceanic Cd and c5 1 3C are preserved in shells of planktonic and benthic foraminifera