Quantitative composition of benthic foraminiferal assemblages as a proxy indicator for organic carbon flux rates in the South China Sea

The organic carbon flux signal embedded in the distribution data of benthic foraminifera from 43 box core surface samples from the South China Sea (SCS) is compared to data from two gravity cores on the northern (core 17940-2) and southern (core 17964-3) slope of the SCS. Surface sampling stations cover almost the entire area of the South China Sea, including areas with preferential summer monsoonal upwelling or winter monsoonal upwelling, as well as a wide range of water depths (300-4000 m). We use correspondence analysis (AFC) to examine the relation between the quantitative composition of benthic foraminiferal assemblages, water depth and organic carbon flux rates. We find a clear correlation between benthic foraminiferal assemblage composition (factor 1 of the AFC) and organic carbon flux rates in the surface samples and use the same model to calculate paleo-flux rates for the two cores. Significantly increased carbon flux rates are observed in the southern SCS (Sunda Shelf margin) during the last glacial maximum (LGM), whereas the organic carbon flux rates along the northern slope of the SCS seem to be highest during the early Holocene. (C) 1999 Elsevier Science B.V. All rights reserved.