Carbonate dissolution and deep-water paleoceanography of the South China Sea since the Middle Pleistocene

Based on the data of oxygen isotope, micropaleontology and paleomagnetism, we set up the detailed chronology of Core 17957-2 from the southern South C hina Sea and discuss the change of carbonate dissolution over the last 800 ka. Down-core variation of carbonate content records the "Pacific-type" cyc le of higher glacial values and lower interglacial values, though the core lies above the modern lysocline. Carbonate dissolution indices indicate tha t several severe dissolution of CaCO3 happened during the transition from i nterglacial to glacial stages. Spectral analyses of these indices show that the carbonate dissolution periodicities are mainly made up of 500 ka and 1 00 ka. Compared with the cycles of carbonate dissolution of the Indian Ocea n, the long-term (500-ka) periodicity reflects the characteristic of the de ep-water circulation of the oceans.