金沙江白鹤滩水电站坝址区断层变形特点及成因分析  

Deformation Characteristics and Genesis of Faults in the Dam of Baihetan Hydroelectric Power Station,Jinsha River

作　　者：金军[1] 杨坤光[2] 

机构地区：[1]中国地质大学研究生院,武汉430074 [2]中国地质大学地球科学学院,武汉430074

出　　处：《地质科技情报》2007年第5期17-22,共6页Geological Science and Technology Information

基　　金：中国水电顾问集团有限公司项目"金沙江白鹤滩水电站可行性研究阶段坝区地质构造研究"

摘　　要：拟建中的白鹤滩水电站坝基将建在二叠系峨眉山组玄武岩层之上。坝址区发育有位移量较小的NW300°、NW320°、NE40°和近SN向4组断层,其中NW300°断层最为发育。在野外详细调查的基础上,室内的显微构造研究和电子自旋共振(简称ESR)测年结果表明,坝址区内的断层是在燕山期晚期近东西向挤压应力场作用下形成,后期又受到了近南北向挤压应力场的改造。断层破碎带以发育典型碎裂-角砾岩等浅层脆性构造岩为特点,近期活动不明显。Baihetan Hydroelectric Power Station of Jinsha River will be built on the Permian E＇mei Mountain basalt. Four-groups faults with small displacement are developed in the dam site,tending NW300°,the NW320°,the NE40° and nearly SN respectively. These faults are mainly dominated by the development of NW300° faults. The detailed field survey,microstructure study and ESR dating on the quartz veins lead to the conclusion that the faults in the dam site was developed early by the closely EW compressive stress field and then changed by the closely SN compressive stress field. Some shallow brittle tectonite such as the typical cataclasite-breccia is developed in the fault zone,however, the activity of faults is weak at present.

关 键 词：断层结构 断层岩 ESR测年 白鹤滩水电站 

分 类 号：P542.3[天文地球—构造地质学]