基于组构组分的变质岩岩相学分类  

A Petrographic Classification Scheme of Metamorphic Rocks Based on Fabric-Components

作　　者：陈能松[1] 夏彬 游振东[1] Chen Nengsong;Xia Bin;You Zhendong(School of Earth Sciences,China University of Geosciences,Wuhan 430074,China)

机构地区：[1]中国地质大学地球科学学院,湖北武汉430074

出　　处：《地球科学》2021年第9期3049-3056,共8页Earth Science

基　　金：国家自然科学基金项目(No.41672060);中国地质大学教学工程项目(No.2018G36).

摘　　要：为建立一个较严密、系统的常见变质岩石的岩相学分类,采用既反映岩石结构构造特征又蕴含岩石基本组成的变质岩组构组分作为岩石分类的一级分类指标,以岩石结构、构造和组构组分的成分依次作为二、三和四级指标,划分了归属于造山区域变质岩、接触热变质岩、断层动力变质岩、蚀变交代变质岩和混合岩这5个大类变质成因的基本岩石.如岩石的地质产状已知,可用对应于地质产状的成因类型变质岩替换组构组分,升级为一级分类指标,然后用同样程序进行划分.本分类方案中,造山区域变质岩与接触热变质岩因具有相同组构组分,因此,大部分基本岩石名称相同,但可借助其地质产状和一些特征变质矿物的特殊显微构造的有无将它们区分开来.本分类方案的分类效果优于国内外现有的岩相学分类方案.In this paper,a classification scheme is proposed for the common metamorphic rocks.In this scheme,the fabriccomponents reflecting both the structure-texture and compositions of metamorphic rocks are used as the first-order index,and the texture,structure and mineral composition are sequentially used as the secondary-,third-and fourth-order indexes for classification of the five genetic types of orogenic-regional,contact thermal,fault-related dynamic,altered-metasomatic metamorphic and migmatitic rocks.When geological occurrence of rocks is clear,the genetic type can replace the corresponding fabric component and becomes the first-order index for classification with the same procedures.Most orogenicregional and contact thermal metamorphic rocks share the same names and features due to having the same fabriccomponents.However,it would be easy to distinguish a regional rock from a contact one according to their mode of occurrence and other characteristic microstructures of some diagnostic minerals.The effect of this classification is better than the petrographic classification schemes available in the world.

关 键 词：组构组分 岩相学分类 变质岩 岩石学 

分 类 号：P588[天文地球—岩石学]