柴北缘沙柳泉-生格一带地质构造分析

发布时间：2018-02-02 07:28

本文关键词： 柴北缘断裂构造特征构造单元构造演化　出处：《长安大学》2015年硕士论文　论文类型：学位论文

【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。
[Abstract]:The study area is located in the northeast Qilian of the Qinghai-Xizang Plateau and the junction of the Qaidam Basin across the South Qilian from the north to the south. For a long time, each tectonic unit has undergone many different periods of tectonic action, and each stage of tectonic development is superimposed on each other. In this paper, based on the previous research data and field geological survey, structural deformation characteristics and tectonic units are divided. Based on the structural evolution process and so on, this paper makes a detailed study and analysis of the geological structure in the area of Shaliuquan-Shengge, and obtains the following points of understanding: 1, due to the particularity of the structural position in the study area. Faults, folds, ductile shear zones, joints and cleavages are well developed in this area. The formation and evolution of each tectonic unit are obviously controlled by faults, and the main structural line is NW to .2. Jinning tectonic cycle and Caledonian tectonic cycle are two important periods of tectonic evolution in this area. The Jinning movement formed the ancient metamorphic crystalline basement caprock in this area and then entered the stage of intracontinental compressional evolution. A series of mesotectonic ductile shear zones and back, trending structures are formed, accompanied by a large number of granitic magma emplacement, and most of the NW-trending faults in this area are formed in Caledonian tectonic cycle .3. The structure in this area can be divided into three tertiary tectonic units from north to south: southern Qilian structural belt, Zongwulong structural belt and northern Qaidam tectonic belt, among which the northern Qaidam tectonic belt is also divided into Oulong Brook block. The three tectonic subzones of Delingha and Maoniushan are further divided into 10 four grade tectonic units. The tectonic evolution of the study area can be divided into four stages: Proterozoic basement generation and evolution. The early Paleozoic ancient continental pyrolysis-subduction collision orogenic stage the late Paleozoic basin-mountain transition stage and the Mesozoic-Cenozoic continental basin evolution stage.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P542

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