糜棱岩形成机制的显微构造证据

糜棱岩是一种空间上呈带状分布的、颗粒度强烈缩减了的叶理状岩石。它是在变形作用、恢复作用和重结晶作用等品质塑性流变过程形成的。产生于韧—隐性条件下的糜棱岩一般都由巨晶和基质两个部分组成,其内保存着丰富的显微构造现象。糜棱岩的光学显微构造现象是其形成机制的证据,同时也是岩石变形环境和条件的判据。本文在描述各类显微构造现象的技础上,从微观变形机制方面对糜棱岩给以必要解释。

MICROFABRIC EVIDENCE FOR MECHANISM OF MYLONITE FORMATION

It is widely accepted that mylonites, rocks of zonal distribution, grain-size reduction and foliation, are products of crystalline plastic flow of rocks suffering deformation, recovering and recrystallization in crastal movement.Mylonites, which formed in the depth of earth crust, consits of phenoerysts and ground masses with rich microstructures which are themseleves brittle fracturing, intracrystalline slipping, dynamic recovering and recrystallization,and even ultraplastic flow or clastic flow, i.e,the mechanism of mylonite formation.