东海陆架盆地南部新生代地质结构与构造演化特征研究

Cenozoic Geological Structure and Tectonic Evolution of Southern East China Sea Shelf Basin

东海陆架盆地是位于欧亚板块中国东部大陆架东缘的中新生代复合断陷盆地,盆地南部具有"东西分带"、"南北分块"的构造格局。盆地内古新世沉降中心在盆地西部的瓯江凹陷;始新世,沉积中心向东迁移,呈现出瓯江凹陷、闽江凹陷和基隆凹陷3个沉积中心特征;渐新世早期,盆地西部开始抬升剥蚀,沉积中心迁移至基隆凹陷,直至中新世盆地西部才再次发生沉降。东海陆架盆地南部新生代构造演化特征可划分为古新世断陷期、始新世断拗转换期、渐新世—中新世拗陷以及上新世以后区域沉降4个时期,盆地东部构造演化时间稍晚于西部。

East China Sea shelf basin as a Mesozoic-Cenozoic composite rift basin is located in the eastern margin of the continental shelf in the eastern China,with E-W zoning and N-S blocking.The subsidence center in the East China Sea shelf basin was located in the Oujiang sag at the Paleocene Period and moved toward east at the Eocene Period,forming three subsidence centers in the Oujiang,Minjiang and Keelung sags.The west part of the East China Sea shelf basin was uplifted and eroded early in the Oligocene,and its subsidence center moved to the Jilong sag,until the middle Miocene,the west part of the East China Sea shelf basin accepted the depositions again.The evolutional stages of Cenozoic tectonic of East China Sea shelf basin are divided into faulted period in Paleocene,fault-to-depression transforming period in Eocene,depression period in Oligocene-Miocene and regional subsidence in Pliocene.