【摘要】 本文在对西太平洋海沟—岛弧—弧后体系与中国东部中新生代构造进行对比的基础上,分析了大洋板块俯冲对大陆构造影响的几个不同阶段。始新世太平洋板块运动方向的改变影响了中国东部的应力场,使左旋剪切变为右旋。中新世前后海沟东撤之后,俯冲对华北的影响变小了。虽然诱发对流消亡了,过剩的重力势引起了地幔物质由洋向陆的侧向流动。蠕变流的数值模拟结果表明中国东部引张与挤压交替的格局是地幔侧向流动的结果。西北太平洋地区的地震旋回可能与这样一种流动的周期性有关。更多还原

【Abstract】 Based on a comparison between the trench-arc-back arc system in west Pacific and the tectonics in easten China during Meso-Cenozoic, several different stages of the effects of subduction on continental tectonics have been analyzed. In Eocene the change in direction of west Paciffc plate motion affected the stress fieid in easten China, where the left lateral shearing was replaced by a right lateral regime. After the eastward retreating of trenches around Miocene, the influence of subduction on North China became small. Though the induced convection was perished, the surplus gravity potential caused a lateral flow of mantle materials from ocean to continent. Numerical modelling of creep flow indicated that the extension-compression altenation of crustal deformation in easten China is the consequence of mantle lateral flow, and the earthquake cycle in north-west Pacific region may be associated with the periodicity of such flow.更多还原