THE CHARACTERIZATIONS AND PALEOCEANOGRAPHIC SIGNIFICANCES OF ORGANIC AND INORGANIC CARBON IN NORTHERN SOUTH CHINA SEA DURING PAST 40 KA

The content of total organic carbon (TOC) and inorganic carbon during the past 40 ka were measured in core 17937 from the northern slope of South China Sea. The results showed that the TOC ex-hibited higher values in glacial period than in interglacial periods, but with reverse pattern for the carbon-ate content. The element ratio of C/N and two components formula analysis indicate that the TOC in the studied area is mainly from the aboriginal organisms, with a relative percent over 80G in Holocene. Calcu-lation from the TOC and the relative percent of the two kinds inputs implied TOC content of the marine or-ganisms was higher in MIS2, indicating higher marine productivity during the last glacial due to the en-hanced nutrition supply by the improved water deep-mixing by strengthened winter monsoon and increased terrigenous inputs. Carbonate content in the area was characterized by "Atlantic Style" by terrigenous sed-iment dilution and a low carbonate event was found during early-middle Holocene which may be the inte-grated result of rapid land dilution, strong carbonate dissolution and lower marine primary productivity.