中国东北—华北新生代火山活动的深部动力学机制  

Geodynamic Mecanism of the Cenozoic Volcanism in the North and Northeast China

作　　者：汪洋[1] 

机构地区：[1]中国科学院地质研究所,北京100029

出　　处：《地质论评》1999年第S1期174-179,共6页Geological Review

基　　金：国家自然科学基金重点项目(编号49733011)资助

摘　　要：在综合地质年代学、数值模拟和岩石学研究成果的基础上,作者提出中国东北—华北地区新生代玄武质火山活动是岩石圈发生拆沉失稳,导致软流圈地幔发生强迫对流的结果。发生在东北—华北地区中部的岩石圈拆沉失稳诱发了早第三纪火山活动,而地幔对流环的扩展引起的热-机械侵蚀作用使得周边地区相继发生岩石圈拆沉,从而导致晚第三纪—第四纪火山活动的产生。拆沉失稳机制得到了大地热流、布格重力异常反演和新构造运动研究结果的支持。Integrating results from geochronology, numerical simulation and petrology, the author proposed that the Cenozoic volcanism in North China(NC) and Northeast China (NEC) was caused by lithosphere delamination and related forced convection in asthenosphere. During the Palaeogene , lithosphere delamination occurred in the central parts of NC and NEC, and induced Palaeogene volcanism. Then the mantle convection cell grew with time. The thermo-mechanic erosion of the convection resulted in delamination under marginal regions of NC and NEC, and caused Neogene—Quaternary volcanism in these regions. Our proposal was supported by terrestrial heat flow data, Bouguer anomaly inversion and neotectonic studies.

关 键 词：火山活动 新生代 拆沉失稳 华北 东北 

分 类 号：P317[天文地球—固体地球物理学]