渤海的形成及其深部动力学机制

THE FORMATION OF BOHAI SEA AND ITS DEEP DYNAMICS

摘要: 燕山运动以来,华北东部地区发生了翻天覆地之构造转变,构造体制从印支期末的地体拼贴、大陆增生,转变为地幔热柱多级演化——渤海海盆伸展裂陷的发展阶段。地形地貌上亦从东部的隆升高原转变为华北东部盆-岭构造,形成了以渤海地幔热柱为中心的大规模裂陷与外围一系列幔枝构造快速隆升的有机组合。渤海的形成是地幔热柱演化的浅部反映,表现为遍及全区强烈的构造运动、大规模的岩浆活动、区域性超变质作用,反映了燕山-喜马拉雅期强烈的幔壳活动。

Abstract: Starting from the Yanshan movement, the tectonic system in the east part of North China has suffered drastic changes.The tectonic regime of the region changed from the merge of terranes and continent accretion of the Indo-Sinian period into the evolution of mantle plume marked by the extensional rifting of the Bohai basin in the later stage. The topography of the legion is also changed from a uplifting plateau to a basin-range system in the east of North China, with the Bohai mantle plume remained in the center characterized by large-scale rifting and series of mantle branches in the periphery. The formation of the Bohai Sea is the result of mantle plume evolution in the shallow part, which caused strong tectonic movement, magmatism and regional ultrametamorphismin in the whole region during the Yanshan-Himalayan period.