PALEOPRODUCTIVITY AND PALEOENVIRONMENTAL CHANGES OF THE NORTHERN SLOPE OF SOUTH CHINA SEA SINCE MIS 6: EVIDENCE FROM DIATOM OF CORE SH1B

Based on the diatom distribution pattern of core SH1B in the Shenhu area, the variation in productivity and paleoenvironment of the northern slope of the South China Sea since the Marine Isotope Stages (MIS) 6 are discussed in this paper. The changes in diatom abundance represent conspicuous glacial/interglacial cycles, resulted from the nutrient input induced by sea level condition. Increasing nutrients supplies from both the intensified river runoffs and upwelling currents during the MIS 2-4 and MIS 6 had led to the high level of primary paleoproductivity. The distribution of the four different diatom ecological assemblages in the SH1B has provided with useful information on paleoenvironment. High percentage of warm temperature species in the ice age of MIS 6 reveals that diatoms are dominantly influenced by salinity. The increased rainfall in the MIS 5 may cause the dominance of coastal brackish species.