湖北浠水蓝晶石铝直闪石片岩中的冠状体结构的研究  

CORONA TEXTURES IN KYANITE GEDRITE SCHIST FROM XISHUI, HUBEI

作　　者：游振东[1] 周汉文[1] 吕学淼 

机构地区：[1]中国地质大学(武汉)地质系 [2]鄂东北地质大队

出　　处：《地球科学（中国地质大学学报）》1990年第4期345-356,共12页Earth Science-Journal of China University of Geosciences

摘　　要：本文对湖北浠水大别前寒武纪变质地体中的蓝晶石铝直闪石片岩进行了研究。研究发现蓝晶石铝直闪石片岩中存在三种类型的冠状体结构:(1)蓝晶石—铝直闪石之间的十字石、堇青石冠状体;(2)十字石—铝直闪石之间的堇青石冠状体;(3)石榴石—铝直闪石之间的堇青石冠状体。这些冠状体结构的存在表明大别前寒武纪变质地体构造发展过程中曾经历过抬升阶段研究表明抬升过程是近乎绝热的,冠状体的结构样式反映了元素扩散速率的差异,冠状体矿物组成的差异则归因于岩石局部总成分的差异。Protolith of the kyanite gedrite schist from the Dabie metamorphic complex near Xishui, Hubei Province, is presumably a Mg- , Fe -rich clay rock. The three types of corona textures that developed within the rocks are as follows: i) The corona of staurolite, cordierite and quartz between kyanite and gedrite; Ⅱ)the corona of cordierite between garnet and gedrite ; Ⅲ) The corona of cordierite between staurolite and gedrite. The petrochemical features of the host rock series, mineral composition of the corona textures and their petrogenesis are dis-cussed in the paper. The development of the corona texture in kyanite gedrite schist indicates that during the evolution of the Dabie Precambrian metamorphic terrain there had been a stage of tectonic uplift which caused a decompressive effect and the formation of the corona tex-ture. It is suggested that the width of the corona indicates the diffussion rate of the elements concerned, and the variation in mineral constituents of the corona can be attributed to the dif-ference in XFe of the host rock.

关 键 词：蓝晶石 铝直闪石 片岩 冠状体 

分 类 号：P588.344[天文地球—岩石学]