论走滑断层作用的几个主要问题

SIME MAJOR PROBLEMS ON STRIKE-SLIP FAULTING

介绍了走滑断层作用研究前缘的若干主要方面。认为普遍使用走滑断层的术语外，在大陆上当断层性质不明时可使用平移断层。强调了单剪机制对大型走滑断层形成的作用，并评论了Ｘ破裂的纯剪理论。基于我国郯庐断裂带等的研究成果，提出走滑断层作用的若干新概念。指出剪曲（牵引）构造不同于雁列褶皱。认为中国地质学家从地质力学研究走滑断层的旋转构造已有卓绝的成就，只要同世界科学接轨，就会获得新的巨大生命力。文中描述了确定位移的方法，提出平移幅度与错距是两个不同的概念。强调了剪切热在大陆构造中的作用，提出走滑剪切带演化中剪切变形－断裂动热变质－重熔岩浆作用旋回。讨论了剪切成矿作用及已成矿体、矿带的走滑错移及变形。划分了三种基本走滑盆地类型及论证了大陆浅源走滑型地震机制。

The author introduces some advanced studies on strike-slip faulting in theworld. It is proposed that the term“wrench faults”should be used in continent when theircharacter is not clear.The role of simple shear mechanism in formation of major strike-slipfaults was emphasized and the X fracture theory of pure shear was reviewed.Based uponthe study of the Tan-Lu fault zone and others in China,some new concepts of strike-slipfaulting were proposed.The shear curve(“drag”)structure is different from the echelonfolds beside strike-slip faults. Chinese geologists have obtained great achievements in thegeomechanical studies of rotation tectonics of strike-slip faults,which will obtain new andgreat vitality provided the former have a scientific exchange with the international geolo-gists. Some methods to establish displacement of a strike-slip fault were described.Dis-placement is different from offset along a strike-slip fault.The role of shear heat is impor-tant in continental tectonics and the shear deformation → fault dynamothemal metamor-physm → remelt magmatism cycle in the shear zone is presented.The shear mineralizationand the displacement and deformation of early ore bodies and zones have been discussed.Three basic types of strike-slip basins are described and the strike-slip type shallow earth-quake mechanism in continent is discussed.