东准噶尔扎曼苏—鲍尔羌吉韧性变形带的基本特征

BASIC CHARACTERISTICS OF ZHAMANSU BAOERQIANGJI DUCTILE ZONE OF EAST JUNGGAR

东准噶尔造山带 1∶ 2 5万区域填图方法研究中 ,在红柳峡南扎曼苏—鲍尔羌吉一带新发现一套韧性变形岩类地层 ,东西长约 70 km,南北宽 4～ 10 km。韧性变形带由上元古界道草沟岩群、扎曼苏岩群、上元古界石英闪长质糜棱杂岩、震旦纪鲍尔羌吉超单元及阿克喀巴克超单元组成。岩石由于经受区域动力变质 ,形成强烈塑性变形和塑性流动的线性狭长构造带 ,产生不同程度的碎裂岩 ,糜棱岩及千糜岩等岩石。韧性变形带中常见 S- C组构、旋转碎斑、石香肠、多米诺骨牌 ,拉伸线理、鞘褶皱、面褶、膝折等构造形态。根据有限应变测量资料和运动学及动力学分析 ,该变形带以压扁型为主 ,且具由南向北的右旋推覆剪切特征 ,在变形过程中至少向北位移了 2 6 km。根据石英动态重结晶测得古应力值为 75.6

During the 1∶250 000 regional geological mapping,we found a set of ductile deformation strata with about 70 kilometers long from east to west and 4 10 kilometers wide from south to north.It is composed of Neo Proterozoic Daocaogou rock group,Zhamansu rock group and Neo Proterozoic quartz diorite mylonite complexes,Baoerqiangji and Akekabake super unit.Dues to the regional dynamometamorphism,the rocks formed a narrow string structural zone of strong plastic deformsation and plastic flow and occur different degree rock of cataclasite,mylonite,phyllonite etc.The common ductile deformations have S C fabrics rotany,mortar,duominuo,stretch lineation,sheath folds,face fold,kink band etc.According to the finite strain measurement data and analysis of kinematic and dynamics,this deformation zone mainly belongs to flattening deformation and has the features of right rotal thrust shear.It moved northward with 26 kilometers in the cause of deformation.The estimated paleo stress value is 75.67 MPa according to the quartz dynamic recrystallization.