板块运动对中国近海新生代盆地沉降及充填的控制作用

太平洋板块、印度板块和欧亚板块的演化对中国近海沉积盆地的沉降及充填具有控制作用。根据地幔对流及地壳拉伸特征可将中国近海沉积盆地沉降类型划分为被动、主动和组合热沉降型3种。不同沉降类型分别具有不同的盆地结构,其中被动热沉降型以断陷为主,主动热沉降型以坳陷为主,组合热沉降型则是两种盆地结构的叠加或侧加。中国近海北部板内沉积盆地沉降类型以被动热沉降为主,远离海洋,受海侵影响较小,以陆相沉积体系为主;中部板缘沉积盆地沉降类型为被动侧加主动热沉降,水体整体较浅,坡折及三角洲发育规模小;南部板缘沉积盆地沉降类型也为被动侧加主动热沉降,水体整体较深,坡折及三角洲发育规模大。

Controls of Plate Motions on Subsidence and Filled Characteristics of the Cenozoic in Chinese Offshore Basins

The evolutions of the Pacific Plate,the Indian Ocean Plate and the Eurasian Plate have the controlling effect to the subsidence and filled characteristics of the Cenozoic in Chinese offshore basins.According to the characteristics of mantle convection and crustal stretching,the subsidence types of Chinese offshore basins can be divided into passive,initiative and combination thermal subsidences.The different subsidence types of sedimentation basins have different basin structures.Rift is the main type in the passive thermal subsidence.Depression is the main type in the initiative thermal subsidence.Vertical or lateral overlapping is the main type in the combination thermal subsidence.The passive thermal subsidence is the main type in northern Chinese offshore basins in internal plates.As away from the sea,these basins are less affected by the transgression which is dominated by the continental sedimentary system.Central Chinese offshore basins in plate margins have the subsidence characteristics which the initiative overlaps the passive in a lateral direction with shallow water,small slope break and delta.Southern Chinese offshore basins in plate margins also have the subsidence characteristics which the initiative overlaps the passive in a lateral direction with deeper water,large slope break and delta.