Grain size, detrital mineral, clay mineralogy (<2 µm), and major element analyses were carried out on the carbonate-free fraction of sediments from Ocean Drilling Program Site 1144 from the northern margin of the South China Sea (SCS), close to the mouth of the Pearl River. This site provides a 517-m sedimentary record extending back to 1.1 Ma. Clay content and the chemical index of alteration do not exhibit significant variation between glacial and interglacial changes, suggesting no important change in the proportion of primary to secondary minerals in the sediment. Two grain size populations were identified, 2.5-5 µm (clay) and 20-40 µm (silt). Glacial stages are characterized by higher proportions of silt size and quartz content than interglacial stages. Two hypotheses can explain these variations: (1) drier conditions associated with an intensification of winter monsoon transport of eolian loess to the northern part of the SCS during glacial periods and/or (2) an effect of sea level changes on the detrital material transport from continent or shelf to the deep ocean.
1Boulay, S., Colin, C., Trentesaux, A., Pluquet, F., Bertaux, J., Blamart, D., Buehring, C., and Wang, P., 2003. Mineralogy and sedimentology of Pleistocene sediment in the South China Sea (ODP Site 1144). In Prell, W.L., Wang, P., Blum, P., Rea, D.K., and Clemens, S.C. (Eds.), Proc. ODP, Sci. Results, 184 [Online]. Available from World Wide Web: <http://www-odp.tamu.edu/publications/184_SR/VOLUME/211/211.htm>. [Cited YYYY-MM-DD]
2FRE 2566 ORSAYTERRE, Université Paris-Sud, 91405 Orsay Cedex, France. Correspondence author: colin@geol.u-psud.fr
3FRE 2255 CNRS, Sédimentologie et Géodynamique, Université des Sciences et Technologies de Lille-SN5, F-59 655 Villeneuve d'Ascq Cedex, France.
4UR Paléotropique, Centre IRD, 72 route d'Aulnay, 93143 Bondy Cedex, France.
5Laboratoire des Sciences du Climat et de l'Environnement, Laboratoire mixte CNRS-CEA, Avenue de la Terrasse, 91198 Gif-sur-Yvette Cedex, France.
6Institut fur Geowissenschaften Geologie, 24118 Kiel, Germany.
7Laboratory of Marine Geology, MOE, Tongji University, 1239 Siping Road, Shanghai, 200092, People's Republic of China.
Initial receipt: 12 September 2001
Acceptance: 1 November 2002
Web publication:
18 February 2003
Ms 184SR-211