【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。更多还原

【Abstract】 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.更多还原