柴北缘沙柳泉—生格一带地质构造分析.pdfVIP

摘 要 研究区地处青藏高原东北祁连、柴达木盆地的交接部位，由北至南横跨南祁连， 宗务隆和柴北缘三个构造单元。由于处在特殊的构造位置，长期以来各构造单元均经 历了多次不同时期的构造作用，各期次构造发展阶段相互叠加，从而形成了复杂的地 质构造现状和演化过程。 本文在结合前人研究资料以及野外地质调查的基础上，从构造变形特征、构造单 元划分、构造演化过程等方面入手，对沙柳泉—生格一带的地质构造进行了详细研究 分析，得到了以下几点认识： 1、由于研究区所处构造位置的特殊性，区内断裂构造、褶皱构造、韧性剪切带、 节理、劈理等构造形迹均十分发育。纵观研究区地质建造及构造形迹，可以看出，各 构造单元的形成与演化明显受断裂控制，主构造线方向为北西西向。 2 、晋宁期构造旋回和加里东期构造旋回是本区构造演化的两个重要时期。晋宁运 动形成了本区古元古代变质结晶基底盖层，之后本区进入陆内挤压演化阶段，形成一 系列中构相韧性剪切带及背、向形构造，并伴有大量的花岗岩浆侵位。而本区大部分 的北西西向断裂均形成于加里东期构造旋回。 3、本区构造由北向南可划分为三个三级构造单元：南祁连构造带、宗务隆构造带、 柴北缘构造带，其中柴北缘构造带又划分为欧龙布鲁克地块、德令哈和毛牛山三个构 造亚带。并进一步划分为10 个四级构造单元。 4 、研究区构造演化过程可分为四个阶段：元古代基底生成与演化阶段、早古生代 古陆裂解—俯冲碰撞造山阶段、晚古生代盆山转换阶段和中、新生代陆相盆地演化阶 段。 关键词：柴北缘、断裂、构造特征、构造单元、构造演化 I Abstract The study area is located in the intersection of northeast of Qilian and Qaidam Basin.From north to south across southern Qilian, Zongwulong and northern margin of Qaidam three tectonic units.Because of its special tectonic location,each structural unit had experienced many times in different periods of tectonic action since long-term.Since superposition the tectonic development stage,its had formed a complex geological structure situation. Based on previous studies and field geological survey,treating structural features, division of tectonic units,the tectonic evolution process and other aspects as the starting point,we detailed study the geological structure of the area of the Shaliuquan and Shengge and obtain the following conclusion: 1.Because of the particularity tectonic location in the study area,its area faults, folds, ductile shear zone, joints, cleavage, structural features are very developed. Throughout the study area geological formation and structure features,we can come to conclusion that the main directi