摘要
对冲绳海槽南部ODP12 0 2站 16 5个沉积物样品进行了CaCO3 含量测定和 4 7个样品以浮游有孔虫为主的微体化石定量分析。应用CaCO3 含量变化与δ18O曲线的对应关系 ,初步将 12 0 2站岩心划分为MIS 1— 5期的沉积。根据浮游有孔虫中暖水、凉水、浅水和深水等生态组合丰度变化 ,推测冲绳海槽南部晚更新世末次间冰期以来 ,温跃层呈逐步加深和表层海水温度逐渐升高的趋势。MIS 5期以较浅温跃层和较低表层海水温度为特征 ,推测与研究区末次间冰期存在上升流有关。末次冰期 (MIS 4— 2期 )时 ,Pulleniatinaobliquiloculata在整个冲绳海槽中普遍以低丰度值出现 。
Records of CaCO_3 content and foraminifera in sediments of ODP Site 1202, southern Okinawa Trough were obtained. Five marine oxygen isotope stages (MIS) 1-5 were recognized by using the corresponding correlation between the CaCO_3 record _( )at this site and δ^(18)O data in core Z14-6 from central Okinawa Trough. Quantitative study of foraminifera showed that abundances of warm and shallow-dwelling species increased from stage MIS 5 to postglacial stage MIS 1, whereas cool and deep-dwelling species decreased correspondingly, reflecting an increase of thermocline depth and surface sea temperature (SST) since stage MIS 5. The lower SST and shallower thermocline in MIS 5 was probably related to upwelling in the area studied. The lowest abundances of P. obliquiloculata during stages MIS 4—2 have been observed in cores from the northern to southern Okinawa Trough, probably indicating that the axis of the Kuroshio migrated out of the Okinawa Trough during those periods.
出处
《海洋地质与第四纪地质》
CAS
CSCD
北大核心
2004年第4期61-66,共6页
Marine Geology & Quaternary Geology
基金
国家自然科学基金资助项目 ( 4 0 2 760 17
40 2 460 0 2 )
国家重点基础发展规划项目 (G2 0 0 0 0 785 0 2 )
