南沙群岛永暑礁90多万年以来的海平面变化

THE CHANGE OF SEA-LEVEL OF YONGSHU REEF IN NANSHA ISLANDS SINCE 900 000 YEARS B.P.

于1990年5－6月在永暑礁礁坪上打一全采芯的地质研究钻井，编号为南永1井，总进尺为15207m，对岩芯详细的地质年代学、地层学、相学和岩石学等进行多学科的分析研究。结果表明，永暑礁地区的海平面目早更新世晚期以来经历了4次上升和间隔的3次下降，形成了4个沉积旋回及其间的3个沉积间断。海平面呈波动式上升趋势。

During May and June, 1990, a geological research core at Yongshu Reefflat named core Nanyong-1 (152.07m deep) was drilled. According to the detailedand multidisciplinary data of geochronology, stratigraphy, facies and petrology ofcore Nanyong- 1, the changillg curve of sea-level of Yongshu areas since 900000years B.P. was drewed. Analytical result showed that the sealevel had 4 rises and 3falls intermediately since late stage of Early Pleistocene, and formed 4 sedimentarycycles and 3 sedimentary interruPted surfaees. Generally, the sea-level rose fluctuatedly.