兴都库什及邻近区域空间应力场特征及其构造意义

兴都库什及邻近区域地处印度洋板块和欧亚板块碰撞带的西缘,是大陆内部中源地震最为活跃的区域,各种数据均显示出该区域有着十分特殊的现象.本文从地质构造、地震分布特征、震源机制解、应力场等方面进行初步分析.结果表明,不同的深度应力场方向表现各不相同,不同的区域震源机制特征各异,尤其是正断层性质地震在北东向表现出了线性展布.通过构造模拟认为该区域可能是在地壳的碰撞、推挤、俯冲作用下出现的褶皱,由于地层倒转嵌入,从而形成了多层位地震密集现象.同时在推挤、拖曳的过程中形成了一条深度约100 km以下的北东向的拉张性破裂.

Characteristics and its structural significance of space stress field in Hindu Kush and adjacent areas

Hindu Kush and its adjacent area are located on the western edge of the collision zone between the Indian Ocean plate and the Eurasian plate,which is the most active area of the mid-source earthquake in the mainland.All kinds of data show that the region has a very special phenomenon.Based on the preliminary analysis of geological structure,seismic distribution characteristics,seismic mechanism solution,stress field and so on,the results show that the performance of stress fields directions is different with the change of depth,different regional seismic mechanisms have different characteristics,and in particular,the earthquake with positive fault properties shows a linear spread in the north-east direction.Through structural simulation,it is believed that the fold may be formed under the influence of collision,push,and subduction of the crust in the area,and the phenomenon of a multi-layer seismic intensity has been formed because the strata are reversed and embedded.At the same time,a northeastward tensile rupture under 100 km depth was formed in the process of pushing and dragging.