周口店房山岩体西缘构造特征及其形成期次探究  

Research on Structual Character and Tectonic Evolution in the Western Margin of Fangshan Pluton,Zhoukoudian

作　　者：周学文[1] 

机构地区：[1]中国地质大学(北京)能源学院,北京100083

出　　处：《科技创新导报》2015年第4期20-23,共4页Science and Technology Innovation Herald

基　　金：大学生创新性实验计划项目(A类):中国地质大学创新创业训练项目资助;项目编号201411415024

摘　　要：周口店房山岩体为燕山褶皱区在J3-K1期大规模岩浆侵入形成的花岗闪长岩岩体。该文根据该岩体西缘车厂韧性剪切带内发育的大量包体、断裂、节理、S-C组构及岩脉等构造特征分析,将岩体西缘的构造演化划分为6个期次。研究认为,车厂地区房山岩体的构造特征记录了其侵位以来不同时期有序的构造演化过程,其内近SN走向的定向排列包体反映了岩体侵位时受围岩挤压的变形特征,NNW和SSW向两组共轭韧性剪切断层为岩体侵位晚期顶部开始冷凝、深部岩体上拱时的产物,SEE-NWW向脆韧性左行剪切断层和近EW向右行脆性剪切断层及其辉石闪长岩岩脉为岩体侵入末期在半固结-固结状态下受外力作用结果,三组原生节理及其硅质条带充填形成于岩体完全冷凝期,在岩体冷凝后又沿节理充填了石英岩脉,此后又在差异风化作用下形成硅质条带突起。Fangshan pluton composed of granodiorite developed in Yanshan fold zone during J3-K1 period in the area of Zhoukoudian. Based on the analysis of large amount of xenoliths,fractures,joints,S-C fabrics and dikes formed in the western margin of the pluton,the development of the pluton are divided into 6 tectonic stages.The results show that,the structural features of the pluton in Chechang district reflect the tectonic evolution process of different stages during its intrusion.The SN trending xenoliths reflect the extrusion features when the pluton intruded;The two NNW and SSW trending conjugated ductile shear faults formed later when the pluton began to upward coagulate;The formation of the left-lateral SEE-NWW trending brittle-ductile shear faults,the dextral EW trending brittle shear faults and pyroxene diorite dikes were the result of external force to the plastic pluton after the intrusion.When the pluton absolutely cooled down,siliceous bands and quartzite fil ed three sets of primary joints.As a result of selective weathering in the later geological period,the siliceous bands protuberance generated on the surface of the pluton.

关 键 词：房山岩体 构造期次 包体 剪切断层 节理 岩脉 

分 类 号：P5[天文地球—地质学]