摘要
北京密云水库西水堡子-梨树沟韧性剪切带的形成与燕山期岩浆活动有关,研究该韧性剪切带的显微构造特征对确定其性质及成因机制具有重要的理论意义。通过野外剖面实测、岩石定向标本采集及镜下显微构造鉴定,表明断层拆离面以下为变质核杂岩,由长英质糜棱岩、糜棱岩化闪长岩、糜棱岩化黑云母片岩及糜棱岩化片麻岩组成。岩石的韧性组构非常发育,长英质矿物中常见蠕英结构、矩形边结构、机械双晶、核-幔结构等。片状矿物中常见S-C组构、云母鱼结构、显微膝折带等。水堡子-梨树沟韧性剪切带为NWW-SEE向剪切的伸展型韧性剪切带。
The formation of the Shuipuzi-Lishugou ductile shear zone on the west side of Miyun Reservoir in Beijing is related to Yanshanian magmatism.Characteristics of microstructures in the ductile shear zone are studied in order to determine its properties and genetic mechanism.Field profile measurement,collection and preparation of oriented specimen and microscopic identification of microstructure showed that the metamorphic core complex below the fault detachment surface is composed of felsic mylonite,mylonitized diorite,biotite schist mylonite and mylonitized gneiss,with well developed plastic deformation fabrics.The quarz-feldspathic minerals in the mylonitized rocks develop myrmekitic texture,rectangular band,mechanical twinning and core-mantle textures etc.,while S-C fabric,mica fish and micro kink are common in flaky minerals.Based on the field investigation and oriented thin section observation,it is considered that the Shuipuzi-Lishugou ductile shear zone is an extensional ductile shear zone with the upper slice shear from NWW to SEE direction relative to the lower slice.
作者
刘恒麟
李忠权
袁四化
尹福光
徐波
彭杨
李根
苏桂萍
丁啸
LIU Henglin;LI Zhongquan;YUAN Sihua;YIN Fuguang;XU Bo;PENG Yang;LI Gen;SU Guiping;DING Xiao(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,China;Key Laboratory of Tectonic Controls on Mineralization and Hydrocarbon Accumulation of Ministry of Land and Resources,Chengdu University of Technology,Chengdu 610059,China;College of Earth Sciences,Institute of Disaster Prevention,Sanhe 065201,China;Chengdu Center of China Geological Survey,Chengdu 610081,China)
出处
《成都理工大学学报（自然科学版）》
CAS
CSCD
北大核心
2020年第4期395-410,442,共17页
Journal of Chengdu University of Technology: Science & Technology Edition
基金
国家自然科学基金项目(41672196)
国家科技重大专项(2016ZX05004-005,2017ZX05008-001)
四川省科技计划项目(2018TY0014,2019YFS00756)
四川省国土资源厅计划项目(KJ-2019-13)。
关键词
变质核杂岩
韧性剪切带
糜棱岩
显微构造
metamorphic core complex
ductile shear zone
mylonite
microstructure
