桂北元古代本洞花岗闪长岩体中发现左旋-正滑型韧性剪切带  

Discovery of sinistral-normal ductile shear zone in Proterozoic Bendong granodiorite pluton

作　　者：张桂林[1] 梁金城[1] 刘之葵[1] 冯佐海[1] 陈懋弘[1] 韩喜彬[1] 

机构地区：[1]桂林工学院资源与环境工程系,广西桂林541004

出　　处：《桂林工学院学报》2003年第1期1-4,共4页Journal of Guilin University of Technology

基　　金：国土资源大调查项目(200113000040-01);广西自然科学基金资助项目(桂科自0229055)

摘　　要：在桂北元古代本洞花岗闪长岩体中首次发现了韧性剪切带,韧性剪切带总体走向为近南北向,糜棱岩面理倾向为240°～280°,倾角为40°～63°;代表剪切运动方向的拉伸线理产状为216°～226°∠39°～46°.韧性剪切带运动学性质为左旋-正滑剪切,滑动方向为由北东向南西方向.韧性剪切带中发育典型的花岗质糜棱岩类,并具有明显的分带现象,从剪切带中心往两侧依次发育千糜岩、糜棱岩、初糜岩.本洞岩体中韧性剪切带和糜棱岩的发现揭示了叠加在元古代本洞岩体之上的一次重要构造事件.The near NS ductile shear zone was first discovered in Proterozoic Bendong granodiorite pluton. It dips toward 240°～280° at the dip angle of 40°～63°. The lineations, which represent the shear direction, plunge to 216°～226° at the plunge angle of 39°～46°. The kinematics of Bendong ductile shear zone is characterized by sinistral-normal shearing, and shows a sliding from NE to SW. Typical granitic mylonites were developed in the ductile shear zone and clearly show a zoning from phyllonite through mylonite to initial mylonite from center to both walls. The discovery of Bendong ductile shear zone and mylonite indicates an important structural event superimposed on Proterozoic Bendong pluton.

关 键 词：元古代 花岗闪长岩 韧性剪切带 糜棱岩 剪切运动方向 

分 类 号：P588.122[天文地球—岩石学] P542.2[天文地球—地质学]