中更新世以来东海陆架的古环境

基于１９９６年中法合作在东海陆架进行的电火花单道地震调查资料，并与位于东海外陆架钻孔ＤＺＱ４对比，发现对应于氧同位素６期以来的六个地震地层与钻孔地层呈现很好的对应关系，其间共有四次海退－海进的沉积旋回。资料分析表明东海第四纪环境演变与全球气候冷暖变化所导致的海面升降直接相关。

PALEO-ENVIRONMENTIN THE CONTINENTAL SHELF OF THE EAST CHINA SEA SINCE THE MID-PLEISTOCENELIU

Based on the data collected in the continental shelf of the China East Sea by Sino French cooperation in 1996,and the correlation with Borehole DZQ4 situated in the outer shelf and obtained by Shanghai Marine Geology Investigation Bureau,a good correspondence was discovered between 6 seismic units since oxygen isotope stage 6 and core sequences.There were four regressive transgressive cycles.Seismic units U2,U3 U4 U5,U6 and U7 are interpreted to correspond respectively to oxygen isotope stages 1,3,5 and 6.U7 is typical of terrestrial features,widely distributed in the shelf of the East China Sea and in even thickness,and can be taken as the marker layer for the Quaternary stratigraphic correlation of the East China Sea shelf.Most of cold strata,which formed on the outer shelf during oxygen isotope stages 2 and 4,are too thin to be recognized,but obvious corresponding erosion surfaces exist.U3,U4 and U5 are in the environment of undersea delta and shallow inner shelf and with a transgression smaller than in the present East China Sea.Holocene transgression was a relatively large one in the East China Sea.Data analyses show that evolution of Quaternary environment in the East China Sea was related to glacio eustatism and global climatic changes.The continental shelf of the East China Sea has been controlled by Pacific tide wave system for a long term,tidal sand ridge sequences which developed in the transgressions,corresponding to oxygen isotope stages 7(or 9),5,3,and 1,have been reserved.