LATE QUATERNARY PALEOCEANOGRAPHY OF THE BANDA SEA

A stable oxygen and carbon isotopic record of benthic (Uvigerina and Cibicidoides species) and planktonic (Globigerinoides ruber) foraminifera recovered from a deep-sea core in the Banda Sea was obtained to develop a better understanding of surface- and deep water hydrography in this region over the last similar to 180 kyr. Higher glacial to interglacial delta(18)O amplitudes of planktonic and benthic foraminifera (1.8 and 1.7 parts per thousand, respectively) indicate an increase in Banda surface and deep water salinity during glacial conditions. Planktonic data is influenced by the precession (23 kyr periodicity) while benthic values reflect intermediate Pacific water fluctuations. The benthic delta(13)C exhibits a depletion of about 0.3 parts per thousand for the last glacial maximum (LGM) relative to the Holocene. A still higher depletion of benthic delta(13)C (0.4-0.6 parts per thousand) occurs during the penultimate full glaciation (stage 6). The main characteristics of delta(13)C in the Banda Sea are a direct record of the delta(13)C global oceanic signal and an evolution similar to intermediate and deep Pacific waters. Banda Sea records indicate a general good ventilation that remained unchanged between glacial and interglacial periods. Variations in the carbon isotopic composition of planktonic foraminifera are attributed to the local variability in monsoonal upwelling or changes in throughflow of pacific intermediate-water masses via Indonesian seas. An increase in the alkalinity and deepening of the lysocline has resulted in higher carbonate content during glacial periods, similar to the results reported in the North Pacific.