浙西南前寒武纪变质岩中韧性剪切带的研究  

THE RESEARCH OF DUCTILE SHEAR ZONE OF PRE-CAMBRIAN METAMORPHIC ROCK IN SOUTHWEST ZHEJIANG

作　　者：李福佩 董传万[1] 王宏伟 

机构地区：[1]浙江大学地科系

出　　处：《地质找矿论丛》1992年第3期12-21,共10页Contributions to Geology and Mineral Resources Research

摘　　要：浙西南前寒武纪变质岩中有七条较大规模的韧性剪切带,它们主要呈NE或NNE向展布,发育在八都群和龙泉群中.笔者主要对其中的两条——法严寺剖面和高亭剖面进行了研究,得出以下结论:a、根据宏观地质考察和利用镜下各种不对称显微构造确定本区韧性剪切带的运动指向为左旋,与江绍断裂的指向一致,后期有脆性变形;b、利用石英动态重结晶颗粒估算古应力值:法严寺为94.3MPa,高亭为86.4MPa;c、糜棱岩带不仅是变形带,而且是变质带.根据糜棱岩中的矿物共生组合和显微构造的组合分析,推断其形成环境相当于绿片岩相.There are seven ductile shear zones developed in Precambrian metamorphic rock in southwest Zhejiang. They mainly extend from NE or NNE to SW or SSW and are developed in Badu group and Longquan group. The authors have researched on two of them along Fayansi section and Gaoting section.Conclusions are made as follows:1) The sense of the ductile shear is sinistral based on the investigation of the macroscopic geologic features and the asymmetric microstructures under microscope. Brittle deformation is appeared during later period.2) The palaeo-stress values in the area are calculated by dynamic recrystallized quartz grain, 94.3 MPa in Fayansi and 86.4 in Gaoting.3) Mylonite belt is not only a deformation belt but also a metamorphic belt. The performing environment is green schist facies inferred from mineral assemblage and microstructure association.

关 键 词：前寒武纪 变质岩 韧性 剪切带 

分 类 号：P588.3[天文地球—岩石学]