南海渐新世以来构造演化的沉积记录——ODP1148站深海沉积物中的证据  

SEDIMENTARY RECORD OF THE TECTONIC EVOLUTION OF THE SOUTH CHINA SEA SINCE THE OLIGOCENE-Evidence from deep sea sediments of ODP Site 1148

作　　者：邵磊[1] 李献华[2] 汪品先[1] 翦知湣[1] 韦刚健[2] 庞雄 刘颖[2] 

机构地区：[1]同济大学海洋地质教育部重点实验室,上海200092 [2]中国科学院广州地球化学研究所,广东广州510640 [3]中海石油研究中心南海东部研究院,广东广州510240

出　　处：《地球科学进展》2004年第4期539-544,共6页Advances in Earth Science

基　　金：国家自然科学基金重大项目"东亚古季风的海洋记录"(编号:49999560);国家自然科学基金重点项目"南海深水扇系统及油气资源"(编号:40238060);国家重点基础研究发展规划项目"地球圈层相互作用中的深海过程和深海记录"(编号:2000078500)资助

摘　　要：南海ODP1148站井深859m、时间跨度32.8Ma,是南海大洋钻探中取芯最长、年代最老的站位,详细记录了渐新世以来南海北部的演变历史。该站位深海沉积物地球化学分析结果显示,自早渐新世以来南海经历了复杂的沉积、构造演变过程。在32Ma、30Ma、28.5Ma、25Ma、23.5Ma和16Ma以及10Ma、8Ma和3Ma沉积物成分存在明显的突变或不连续面。特别是在晚渐新世沉积物成分发生剧烈改变,并伴有沉积间断和滑塌作用,代表着南海以及我国东部地区一次重大构造运动,该构造运动对我国近代地理格局的形成以及我国东部地区众多陆相盆地由断陷型转为坳陷型起到了极为关键的作用。ODP Leg 184 Site 1148 recovered up to 859 m deep-sea sediments spanning the fast 32.8 Ma from the northern South China Sea (SCS), which is the longest record known so far in recording the detail evolutionary history of the SCS since the Oligocene. Geochemical analysis reveal that the SCS has undergone complicated sedimentary and tectonic evolutionary processes. The composition of the sediments had obvious changes or discontinuities at 32 Ma, 30 Ma, 28.5 Ma, 25 Ma, 23.5 Ma, 16 Ma, 10 Ma, 8 Ma and 3 Ma, respectively, reflecting tectonic or environmental turning points. Especially, the great discontinuous change in the sediment composition at the Oligocene/Miocene boundary with slumps and sedimentation breaks indicates a period of important tectonic activities in the SCS and Eastern China areas. This tectonic event played a key role in the transforming of many sediments basins in the Eastern China from graben basins to down-warped basins, as well as in the formation of the general topographic character in the region.

关 键 词：南海 构造 深海沉积 地球化学 渐新世 

分 类 号：P736[天文地球—海洋地质]