内蒙古中部苏尼特左旗地区勃勒金韧性剪切带的厘定及其地质意义

发布时间：2018-05-10 23:25

本文选题：韧性剪切带 + 早二叠世　；参考：《现代地质》2017年03期

【摘要】：通过野外地质调查和室内显微构造分析,在内蒙古中部苏尼特左旗北部勃勒金一带厘定出一条NEE走向,往北倾,倾角70°~85°的左行逆冲型韧性剪切带。该韧性剪切带内发育糜棱岩系列、糜棱面理、拉伸线理、S-C组构、不对称褶皱、旋转碎斑、书斜构造和云母鱼构造等宏观和微观构造。野外观察表明,勃勒金韧性剪切带由若干条强变形带和其间的弱变形域组成,平面上呈现平行状展布,出露长约10 km,宽约4 km。在对韧性剪切带宏观、微观构造特征和锆石U-Pb年代学研究的基础上,结合区域资料,认为勃勒金韧性剪切带是区域上查干敖包—阿荣旗深断裂的构造形迹,形成于早二叠世早期(290~292 Ma),是古亚洲洋闭合、西伯利亚板块和华北板块南北向汇聚碰撞的产物。勃勒金韧性剪切带的厘定为兴蒙造山带晚古生代构造演化提供了基础资料。
[Abstract]:Based on field geological investigation and laboratory microstructural analysis, a NEE strike is determined in the northern part of Sunita left Banner in central Inner Mongolia, with a northerly dip of 70 掳to 85 掳left thrusting ductile shear zone. In the ductile shear zone, there are mylonite series, mylonitic texture, extensional lineage, S-C fabric, asymmetric fold, rotating patch, book-oblique structure and mica fish structure, etc. The field observation shows that the bracken ductile shear zone is composed of several strong deformation zones and their weak deformation regions, which are distributed in parallel shape on the plane, with a protruding length of about 10 km and a width of about 4 km. On the basis of macroscopical and microstructural characteristics of ductile shear zone and U-Pb chronology of zircon, combined with regional data, it is considered that the ductile shear zone is the structural trace of the deep fault of Chagan Aobo-Aronqi in the region. It was formed in early Permian (early Permian) and was the result of the closure of the Paleo-Asian Ocean and the convergence and collision of the Siberian plate and the North China plate in the north-south direction. The determination of Blejin ductile shear zone provides basic data for the late Paleozoic tectonic evolution of the Xingmeng orogenic belt.
【作者单位】：河北地质大学资源学院;
【基金】：中国地质调查局地质调查项目“内蒙古1∶5万准和热木音苏木(L49E021018)等六幅区域地质矿产调查”(1212011220458)
【分类号】：P542

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