During Ocean Drilling Program (ODP) Leg 184, six sites were drilled in two areas of the South China Sea. The major aim of ODP Leg 184 was to reconstruct the evolution and variability of the East Asian monsoon to better understand the links between tectonic uplift, monsoons, and global climate variation (Wang, Prell, Blum, et al., 2000). Site 1143 is located in the southern part of the basin. It was chosen to capture the long-term record of sediment accumulation rates and lithologic variability associated with the Mekong and Sunda River systems, which might be related to the uplift and denudation of Tibetan and East Asian tectonic systems (Wang, Prell, Blum, et al., 2000).
Except for surface sediment studies (Calvert et al., 1993), inorganic geochemical studies of South China Sea sediments are rare. In this chapter, we present major and minor element data of Pliocene cores from ODP Site 1143. These data provide information on the relative contribution of terrigenous detrital matter from different provenances (e.g., Wehausen and Brumsack, 1999) or of weathering intensity (e.g., Schneider et al., 1997). Furthermore, variations in biological productivity or diagenesis can be reconstructed based on barium (Dehairs et al., 1980; Dymond et al., 1992), phosphorus (Delaney, 1998), or redox-sensitive trace element abundance (Calvert and Pedersen, 1993). The oxygen isotope stratigraphy of Tian et al. (this volume) provides a stratigraphic framework that will be applied to interpret changes in sediment geochemistry with respect to glacial-interglacial stages. A comparison of elemental proxy data with the benthic oxygen isotope curve may provide information about the relationship between terrigenous input, monsoons, sea level changes, and glacial climates.