摘要
ODP1148站以及珠江口盆地沉积物均记录了渐新世末发生的重大地质构造事件,这一构造事件在时间上与南海扩张轴发生跳跃的时间十分吻合,是渐新世以来南海构造演化史上最为重大的构造事件,涉及到南海扩张、盆地类型转化、沉积物源变迁等一系列相关联的重大地质事件.伴随这一地质构造事件,南海北部沉积物成分发生剧烈改变,出现渐新世-中新世地球化学成分上的跳跃,在深海沉积中发生沉积间断及滑塌事件,并使珠江口盆地由断陷型盆地转为坳陷型盆地,白云凹陷由渐新世晚期的浅水陆架环境转为中新世以后的深水陆坡环境.可以认为,这次构造运动奠定了我国现代的地理格局,也标志着我国东部陆相盆地最佳烃源岩形成期的结束,在南海乃至东亚地区影响深远.
A significant tectonic event was recorded in late Oligocene sediments from ODP Site 1148 and Pearl River Mouth Basin. This tectonic event coincided with the seafloor spreading axis jump event across the Oligocene/Miocene boundary, leading to a series of changes not only in seaftoor spreading direction but also types of sedimentary basins and sediment provenances, and representing the greatest tectonic activity in the South China Sea region since the Oligocene. Sedimentation breaks and slumps as well as obvious changes in sediment composition across the Oligocene/Miocene boundary indicate the existence of the tectonic event, which transformed the Pearl River Mouth Basin from a graben basin to a down-warped basin, and the sedimen tary environment in the Baiyun Sag area from continental shelf in the late Oligocene to continental slope since the early Miocene. It played a key role in the transformation of the general topographic character in continental China and ended a period of accumulation of good source rock for petroleum offshore. Therefore, this tectonic event has a profound influence on the evolution of the South China Sea and East Asia.
出处
《地球科学（中国地质大学学报）》
EI
CAS
CSCD
北大核心
2009年第5期717-724,共8页
Earth Science-Journal of China University of Geosciences
基金
国家重点研究专项经费(No.2007CB819501)
国家科技重大专项(No.2008ZX05000-025)
创新研究群体基金(No.40621063)
关键词
南海
白云凹陷
渐新世
海底扩张
构造事件.
South China Sea
Baiyun Sag
Oligocene
seafloor spreading
tectonic event.
