阿尔金断裂:几何学、性质和生长方式  

The Altun Fault: Its Geometry, Nature and Mode of Growth

作　　者：崔军文[1] 张晓卫[1] 李朋武[1] 

机构地区：[1]中国地质科学院地质研究所,北京100037

出　　处：《地球学报》2002年第6期509-516,共8页Acta Geoscientica Sinica

基　　金：原地质矿产部(项目批准号:86-06-207);国家科委(项目批准号:96-915-06-04);国土资源部大陆动力学开放实验室(项目批准号:9812)资助。

摘　　要：阿尔金断裂具有线性与弧形相叠加的几何学特征及强烈的时空不均一性,阿尔金断裂是一条同时具有逆冲、左行走滑和正滑复杂力学性质的巨型断裂系。走滑作用和正滑作用的主要时期分别为白垩纪-新生代和上新世-第四纪,逆冲作用则是晚古生代以来一直起主导作用的变形事件（大约305Ma以来）。阿尔金断裂的形成与其两侧地块的强烈不均一变形（阿尔金山腹地以收缩变形为主,祁连地块以逆冲扩展为主）有关,它经历了分段破裂、逐段连接和逐渐扩展的动力学过程,其形成与祁连地块中的上叠式逆冲序列和青藏高原隆升同步,随着自南而北逆冲扩展和青藏高原隆升的不断加剧,阿尔金断裂北东端点往北东方向扩展,南西端点往南西方向生长,这一运动学过程持续至今。The Altun (or Altyn) fault displays a geometry of overlapping of linear and arcuate segments and shows strong inhomo-geneity in time and space. It is a gigantic fault system with complex mechanical behaviors including thrusting,sinistral stike slip and normal slip. The strike slip and normal slip mainly occurred in the Cretaceous-Cenozoic and Plio-Quaternary respectively, whereas the thrusting was a deformation event that has played a dominant role since the late Paleozoic (for a duration of about 305 Ma). The formation of the Altun fault was related to strong inhomogeneous deformation of the massifs on its two sides (in the hinterland of the Alun Mountains contractional deformation predominated and in the Qilian massif thrust propagation was dominant). The fault experienced a dynamic process of successive break-up and connection of its segments and gradual propagation, which was synchronous with the development of an overstep thrust sequence in the Qilian massif and the uplift of the Qinghai-Tibet plateau. With southward propagation of the thrust sequence and continued uplift of the plateau, the NE tip of the Altun fault moved in a NE direction, while the SW tip grew in a SW direction.

关 键 词：几何学 阿尔金断裂 逆冲序列 扩展 左行走滑 生长方式 

分 类 号：P542.3[天文地球—构造地质学]