板内盆地地震构造分析──以江苏南部为例

板内地震构造的主要控制因素是区域构造应力场和局部的特殊发震构造条件。本文提出江苏南部强地震的主要构造标志是新生代活动盆地，盆地内的隐伏发震断层与区域构造应力场的最大主应力之间的夹角正好有利于剪切破裂的发生。三维有限元数值模拟证明，盆地形成过程中产生的地壳脆弱化，导致构造应力的重新分布和局部集中，盆地内部脆弱体中的隐伏断层是潜在的震源破裂面，盆地边缘积累的弹性应变能则是地震时释放的能量来源。

ANALYSES FOR SEISMOTECTONICS OF INTRAPLATE BASINS: AN EXAMPLE OF SOUTHERN JIANGSU PROVINCE

The main controlling factors of intraplate earthquakes are the regional tectonic stress field and the special conditions for the seismogenic structures. It is suggested that the most important indictors for the moderately strong earthquakes in southern Jiangsu province are the active basins of the Cenozoic era. The buried seismogenic faults within the basins are suitably oriented with respect to the maximum stress of the regional tectonic stress field which is favour of shear ruptures. Results of three dimensional numerical modeling by the finite element method demonstrate that the weakened zone of the crust in thebasins could give rise to redistribution and local accumulation of the tectonic stress. The buried faults re-lated to the zone of weakeness in the basins may be the potential sites of seismic ruptures. The elasticstrain energy built up near the edges of the basin can be the driving force for occurrence of earthquakes.