Oxygen and carbon isotope records of calcareous nanno-fossils for the past 1 Ma in the southern South China Sea  

作　　者：LIU Chuanlian CHENG Xinrong ZHU Youhua TIAN Jun XIA Peifen 

机构地区：[1]Key Laboratory of Marine Geology of Ministry of Education,Tongji University,Shanghai 200092,China [2]Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences,Nanjing 210008,China

出　　处：《Chinese Science Bulletin》2002年第10期798-803,共6页

基　　金：This work was supported by the National Key Basic Research Special Foundation Project (Grant No. G2000078502);the National Natural Science Foundation of China (Grant No. 49999560).

摘　　要：Oxygen and carbon isotopic analyses have been carried out on calcareous nannofossils from ODP Site 1143 in the southern South China Sea. The results demonstrate that the δ18O values of calcareous nannofossils for the past 1 Ma vary systematically with those of planktonic and benthic foraminifera from the same site. But the average δ18O value of nannofossils is 1.869‰ higher than that of planktonic foraminifera, and is 3.855‰ lower than that of benthic foar-minifera. There are systematic differences between the δ13C values of nannofossils, planktonic foarminifera and benthic foraminifera. The average δ13C of nannofossils is 0.756‰ higher than that of benthic foraminifera, and is 0.460‰ lower than that of planktonic foraminifera. The δ13C values of nannofossils exhibit a significant positive shift beginning near isotope stage 14 and lasting until stage 8. This study also finds that there is a close ralationship between the δ13C of nannofossils and the percentage of Florisphaera profundo. ThisOxygen and carbon isotopic analyses have been carried out on calcareous nannofossils from ODP Site 1143 in the southern South China Sea. The results demonstrate that the δ18O values of calcareous nannofossils for the past 1 Ma vary systematically with those of planktonic and benthic foraminifera from the same site. But the average δ18O value of nannofossils is 1.869‰ higher than that of planktonic foraminifera, and is 3.855‰ lower than that of benthic foarminifera. There are systematic differences between the δ13C values of nannofossils, planktonic foarminifera and benthic foraminifera. The average δ13C of nannofossils is 0.756‰ higher than that of benthic foraminifera, and is 0.460‰ lower than that of planktonic foraminifera. The δ13C values of nannofossils exhibit a significant positive shift beginning near isotope stage 14 and lasting until stage 8. This study also finds that there is a close ralationship between the δ13C of nannofossils and the percentage of Florisphaera profunda. This implies that the δ13C of nannofossils can be used as an indicator of sea water surface paleoproductivity.

关 键 词：oxygen and carbon ISOTOPE CALCAREOUS NANNOFOSSIL SOUTH China Sea. 

分 类 号：P597[天文地球—地球化学]