Paleoproductivity variations in the southern Okinawa Trough since the middle Holocene:Calcareous nannofossil records  

作　　者：ZHAO JingTao LI TieGang LI Jun HU BangQi 

机构地区：[1]Key Laboratory of Marine Geology and Environment,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China [2]Key Laboratory of Marine Hydrocarbon Resource and Geology,Ministry of Land and Resources,Qingdao Institute of Marine Geology,Qingdao 266071,China [3]Key Laboratory of Marginal Sea Geology,South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou 510301,China

出　　处：《Chinese Science Bulletin》2012年第30期3917-3922,共6页

基　　金：supported by the Pilot Project of the Knowledge Innovation Program of Chinese Academy of Sciences (KZCX2-YW-221);the National Natural Science Foundation of China(40906033 and 40976036);the Open Foundation of Key Laboratory of Marginal Sea Geology,Chinese Academy of Sciences (MSGL09-11 and MSGL12-01)

摘　　要：Based on 17 AMS 14 C age data,we reconstructed high-resolution records of sea surface primary productivity(PP) in the southern Okinawa Trough(MD05-2908) over the last 6.8 ka BP using the calcareous nannofossil carbon isotope and the relative percentage contents of Florisphaera profunda indexes.The underlying mechanism controlling the sea surface PP was then discussed.The sea surface PP,indicated by the coccolith δ 13 C and %Fp conversional equations,decreased with some fluctuations since 6.8 ka BP.This decrease may be connected to the decreased terrigenous input resulting from the reduced East Asian Summer Monsoon(EASM) precipitation.Both the periods of 4-2 ka BP(PME) and 6.8-4.8 ka BP were characterized by relatively higher PP.The former was mainly controlled by the weakening of the Kuroshio Current,whereas the latter mainly resulted from the greater terrigenous input associated with the stronger EASM.Based on 17 AMS14C age data, we reconstructed high-resolution records of sea surface primary productivity （PP） in the southern Okinawa Trough （MD05-2908） over the last 6.8 ka BP using the calcareous nannofossil carbon isotope and the relative percentage contents of Florisphaera profunda indexes. The underlying mechanism controlling the sea surface PP was then discussed. The sea surface PP, indicated by the coccolith δ^13c and %Fp conversional equations, decreased with some fluctuations since 6.8 ka BP. This decrease may be connected to the decreased terrigenous input resulting from the reduced East Asian Summer Mon- soon （EASM） precipitation. Both the periods of 4-2 ka BP （PME） and 6.8-4.8 ka BP were characterized by relatively higher PP. The former was mainly controlled by the weakening of the Kuroshio Current, whereas the latter mainly resulted from the greater terrigenous input associated with the stronger EASM.

关 键 词：钙质超微化石 冲绳海槽 古生产力 化石记录 中全新世 东亚夏季风 高分辨率记录 陆源物质 

分 类 号：P736.22[天文地球—海洋地质] P736.41[天文地球—海洋科学]