韧性剪切带及其变形岩石

本文讨论了地壳和上地幔中韧性剪切带及其中的变形岩石。在大多数情况下,韧性剪切带中的变形岩石为糜棱岩,因为经受韧性剪切变形时,岩石的粒度显著减小并发育了强化的叶理(线理)。但是在某些情况下,例如,当隐晶质灰岩及富含长石的岩石经受韧性剪切变形时,剪切带中的变形岩石粒度局部增大或者没有发生明显减小,它们并不是典型的糜棱岩。由于变形环境、变形介质及变形机制的不同,韧性剪切带内岩石变形的产物是不同的

DUCTILE SHEAR ZONES AND THEIR DEFORMED ROCKS

This paper deals with the ductile shear zones and their deformed rocks in the crust and upper mantle. In most cases, the deformed rocks within ductile shear zones are my-lonites, because rock grain size obviously reduced and strengthening foliation (lineation) developed. In some cases, however, when aphanitic limestone or feldspar-rich rocks undergo ductile shearing, the deformed rocks within shear zones show local increase of rock grain size or no remarkable grain size reduction. They are not typica Imylonites. It is evident that the deformation products of rocks within the shear zones are differernt due to different deformation condition, deformation medium and deformation mechanism.