A record of deep-sea calcite saturation (D[CO3**-2]), derived from X-ray computed tomography-based foraminifer dissolution index, XDX, was constructed for the past 150 ka for a core from the deep (4157 m) tropical western Indian Ocean. G. sacculifer and N. dutertrei recorded a similar dissolution history, consistent with the process of calcite compensation. Peaks in calcite saturation (~15 µmol/kg higher than the present-day value) occurred during deglaciations and early in MIS 3. Dissolution maxima coincided with transitions to colder stages. The mass record of G. sacculifer better indicated preservation than did that of N. dutertrei or G. ruber. Dissolution-corrected Mg/Ca-derived SST records, like other SST records from marginal Indian Ocean sites, showed coolest temperatures of the last 150 ka in early MIS 3, when mixed layer temperatures were ~4°C lower than present SST. Temperatures recorded by N. dutertrei showed the thermocline to be ~4°C colder in MIS 3 compared to the Holocene (8 ka B.P.).
Kiefer, Thorsten; McCave, I Nick; Elderfield, Henry (2006): Antarctic control on tropical Indian Ocean sea surface temperature and hydrography. Geophysical Research Letters, 33(24), L24612, doi:10.1029/2006GL027097
Kiefer, Thorsten; McCave, I Nick; Elderfield, Henry (2006): Stable isotopes and sea surface temperature on planktic foraminifera of sediment core WIND 28K. doi:10.1594/PANGAEA.610271
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Fonte
Supplement to: Johnstone, Heather J H; Kiefer, Thorsten; Elderfield, Henry; Schulz, Michael (2014): Calcite saturation, foraminiferal test mass, and Mg/Ca-based temperatures dissolution corrected using XDX-A 150 ka record from the western Indian Ocean. Geochemistry, Geophysics, Geosystems, 15(3), 781-797, doi:10.1002/2013GC004994
