三维参照变形及应变相研究评述

三维参照变形和应变相是最近构造地质学领域中取得的重要进展，三维参照变形是理想化的三维变形分类，每一参照变形是共轴级分（拉伸、压扁或纯剪）和与其垂直的简单切组分同时作用的产物，三种可能的面理取向和三种可能的线理取向的不同组合构成六咱应变相，三维参照变形和应变相研究证明糜陵面理未必平行剪切带，可与剪切带斜交，甚至垂直，线理未必与剪切方向一致，可与剪切方向斜交，甚至垂直，出现横向面理时，剪切指向标志位于该面理内，出现横向线理时，剪切指向出现在与线理垂直的ａｃ面理内，三维变形分析不公可解决三维分析难以解释的横向面理和线理，而且可确定共轴组分的类型及其与单剪组分的结合方式。

REVIEW ON THE THREE-DIMENSIONAL REFERENCE DEFOR MATIONS AND STRAINS FACIES

Three dimensional reference deformations and strain facies are new advances in structural geology.The former is an idealized category for three dimensional deformations,each being a result of a three dimensional coaxial component(stretching,flattening or pure shear)and an orthogonal simple shear component.There are three possible orientations of lineation and three possible orientations of foliation,which may constitute six strain facies.Three dimensional reference deformations and strain facies suggest that the mylonitic foliation is unnecessarily parallel with the shear zones,and may have an oblique or even a perpendicular relation to the shear zone,and that the lineation is not necessarily in the shear direction,and may be in an oblique or even in the normal direction to the foliation.When a transverse foliation occurs,markers of shear sense are in the foliation, and where a transverse lineation appears,indicators of shear sense are in the ac plane which is normal to the lineation.Three dimensional analysis may not only solve the problem of the formation of transverse foliation and lineation,which is difficul for 2D analysis to explain,but also will determines the type of coaxial component and the combining pattern of coaxial and simple shear components in certain three dimensional deformation.