琼东南盆地晚第三纪浮游有孔虫深度分层意义

依据Ｋｅｌｌｅ１９８５年、Ｇａｓｐｅｒｉ等１９９３年有关中新世印度洋和太平洋浅层水、中层水和深层水浮游有孔虫深度分层组合的划分模式，对南海琼东南盆地崖１３－１－４井晚第三纪浮游有孔虫作了定量研究，并分析了陆架海区浮游有孔虫不同深度分层组合含量的变化与古地理环境变迁的关系。崖１３－１－４并以浅层水、中层水组合为主，深层水组合不发育，反映该区温跃层不发育，不利于深层水浮游有孔虫的生存。滨海区，浮游有孔

SIGNIFICANCES OF DEPTH STRATIFICATION OF LATE TERTIARY PLANKTONIC FORAMINIFERA OF BASIN IN SOUTHEASTERN HAINAN PROVINCE

According to the classification model of depth stratification of planktonic foraminifera in Miocene Indo Pacific Ocean (Keller,1985;Gasperi & Kennett,1993),Late Tertiary planktonic foraminiferal species from Ya 13 1 4 oil well in Qiongdongnan basin of the northern part of South China Sea could be grouped into the shallow,intermidiate and deep water dwelling groups.There existed a good relationship between percentage changes of these three planktonic foraminifera groups and paleogeographic distributions.Planktonic foraminifera from sediments of Ya 13 1 4 are dominated by shallow and intermidiate water dwelling species.The deep water dwelling species are not found in the samples,indicating that sea water was not deep enough for deep water dwelling species or the thermocline was too deep during Late Tertiary in the site of Ya 13 1 4.Planktonic foraminifera from the littoral sediments are dominated by a few shallow water dwelling species,those from inner neritic sediments are characterized by a relative high percentage of shallow water dwelling species and a low percentage of intermidiate water dwelling species and those from outer neritic sediments are characterized by a relative high percentage of intermidiate water dwelling species.Outer neritic environment has taken placed in Middle and Lower Pliocene in the site of Ya 13 1 4 oil well.