【摘要】 受青藏高原物质在南北挤压下向东逸出的影响 ,四川地块、鄂尔多斯地块、川滇地块和滇西地块均发生了不同性质的变形响应。根据航磁异常揭示的四川、鄂尔多斯盆地基底构造样式和滇西地区的地质构造研究结果 ,在主要由变质褶皱基底组成的四川地块发生平行龙门山断层的逆冲推覆 ,基底岩石发生递进褶皱缩短的同时 ,由华北变质结晶基底组成的鄂尔多斯地块在前期逆冲推覆构造的基础上 ,结晶基底沿一系列近东西向左行走滑断层向东错移。滇西和川滇地块则分别沿金沙江—红河断裂 (2 0Ma前后 )和鲜水河—小江断裂 (5Ma前后 )发生了大规模的左行位移。发生在滇西、川滇、四川和鄂尔多斯地块上的最新构造变动叠加或改造了先存构造 ,并且表现为从南向北、由盖层向基底发展的趋势 ,变形程度自西向东减弱 ,反映了青藏高原持续同构造伸展作用的边缘和远程效应。青藏高原东缘多层次、多阶段的现今构造变动引发的地震活动组成了宏观的南北地震带。更多还原

【Abstract】 Various deformation responses to the eastwards escaping of the Qinghai-Xizang (Tibet) Plateau occurred in the adjacent blocks of Sichuan, Ordos, Chuandian and Dianxi. According to the tectonic interpretation of aeromagnetic anomalies in the regions of Sichuan and Ordos basins, and field investigation carried out in west Yunnan Province, the Ordos block was contorted in left lateral sense along a series of E-W trending strike slip faults, which occurred in the high-grade metamorphic basement following previous thrusts; while the metamorphic folded basement under Sichuan basin had shortened parallel to Longmenshan thrusts. The Dianxi and Chuandian block moved in left lateral sense along Jinshajiang—Honghe fault earlier (around 20 Ma) and along Xianshuihe—Xiaojiang fault later (about 5 Ma), respectively. The neotectonic events that occurred in Dianxi, Chuandian, Sichuan and Ordos regions represent the marginal and long distance effects resulting from the syn-tectonic extension of the Qinghai-Xizang Plateau, which overprinted and reworked all previous structures in the blocks. It seems that the deformation developed from south to north and from cover to basement progressively, and weakened from west to east. The seismicity caused by recent deformation in multi-levels and multi-stages at the east edge of Qinghai-Xizang Plateau makes up the South-North Seismic Zone.更多还原