Stable isotopic records of the glacial deep-water properties in the South China Sea
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Based on the oxygen and carbon stable isotopic records of benthic foraminifera in nine deep-sea cores of the South China Sea (SCS), the bathymetric profiles of δ18O and δ13C since the last glacial maximum (LGM) are preliminarily established. The bathymetric gradients of deep-water δ18O and δ13C in the SCS are obviously greater during the LGM than during the Holocene, showing the existence of the deep thermocline and nutricline at water depth of about 2 000 m. Particularly, the differences in δ18O and δ13C between the LGM and Holocene, from which the ice-volume effect and the global mean shift have been subtracted respectively, are positive values at water depths of 1 000–2 500 m in the SCS. This indicates the existence of deep-water mass with relatively cool temperature or higher salinity, better ventilation and more δ13C within the water depth range of the SCS during the LGM, which is distinctly different from that at present. These changes further confirm the existence of the glacial “North Pacific Deep Water” which, however, is possibly confined to the water depth range of 1 000–2 500 m.
Keywordsstable isotope deep thermocline and nutricline North Pacific Deep Water the South China Sea
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- 7.Qian, J., Studies on stable oxygen and carbon isotope records and accumulation rates in Core 8KL of the South China Sea from oxygen isotope stage 6 (in Chinese with English abstract),Acta Sedimentologica Sinica, 1994, 12(3): 21.Google Scholar
- 8.Winn, K., Zheng, L., Erlenkeuser, H. et al., Oxygen/carbon isotopes and paleo-productivity in the South China Sea during the past 110 000 years, inMarine Geology and Geophysics of the South China Sea (eds. Jin, X., Kudrass, H. R., Pautot, G.), Beijing: China Ocean Press, 1992, 154–166.Google Scholar
- 9.Kudrass, H. R., Schonfeld, J., Erlenkeuser, H. et al., The last glacial-interglacial transition in the South China sea recorded by stable isotopes of benthic and planktonic foraminifera, inProgram & Abstracts of Fourth International Conference on Paleoceanography, Kiel: Geomar Report 15/Berichte-Reports 57, 1992, 170.Google Scholar
- 10.Zahn, R., Winn, K., Sarnthein, M., Benthic forarniniferal δI3C and accumulation rates of organic carbon:Uvigerina peregrina group andCibicidoides wuellerstorfi, Paleoceanography, 1986, 1: 27.Google Scholar
- 14.The State Oceanic Administration,Report of Comprehensive Investigations on Environmental Resources in the Central Part of the South China Sea (in Chinese with English abstract), Beijing: China Ocean Press, 1988, 1–519.Google Scholar
- 15.Jian, Z., Greatly increased influence of the Deep Water Mass in the western Pacific during the last glacial maximum,Chin. Sci. Bull., 1996, 41(6): 496.Google Scholar