【作者】 陈云峰；

【导师】 吴淦国； 王根厚；

【作者基本信息】 中国地质大学（北京） ， 构造地质学， 2007， 博士

【摘要】 位于华北板块北缘的燕山造山带,是中国地质工作的摇篮地区之一,以中新生代强烈的板内变形而闻名于世。从上个世纪初开始,国内外学者就这一地区中新生代及早前寒武纪的地质与构造问题开展了大量的研究工作,取得了许多重要的认识。但对于燕山东段的中生代变形序列及变形机制一直存在较大的争议。研究区自结晶基底固结以来,经历了多期不同体制和不同方向的构造变形,发育逆冲推覆构造、伸展构造和走滑构造等不同期次构造,即近东西向的青龙河走滑断裂、北东向褶皱-断裂系、北西向冷口断裂。以上三组方向的构造系统都具有多期变形的特征,记录了燕山东段的中生代的变形历史,因此值得深入研究。本文采用构造解析方法对研究区的构造特征进行研究,通过地质调查,在不同的尺度上把复杂的变形加以分解,分析其几何学、运动学、动力学及变形环境和变形序列,从而进一步分析构造变形的发展、演化规律和变形机制。在此基础上探讨燕山造山带板内变形的动力学机制。通过本论文的研究,取得了一些新的认识及进展,主要包括以下几个方面:1、北东向断裂系统发育时期为早燕山期,受北西-南东向的构造挤压作用形成,挤压阶段形成了研究区内的李家窝铺-三道河子断裂,断裂运动形式为逆-右行走滑。挤压过后,区内转为拉张背景,李家窝铺-三道河子断裂发生了一定程度的正断作用,此外,该断裂上盘地层也顺软弱带发生了伸展作用,形成了区内的马杖子-安达石断裂。2、东西向青龙河断裂为一条形成于太古宙的基底断裂,对区内盖层沉积起到了一定的控制作用,该断裂在中生代发生活化。断裂活动经历了印支期的南北向挤压,早燕山期的北西-南东向挤压及后期的伸展作用。断裂记录最明显的为早燕山期的右行走滑运动。3、北西向冷口断裂在燕山地区属于一个构造特例,形成于燕山结晶基底裂解时期,为中元古代蓟-辽裂陷盆地内一条转换断裂,于中生代发生活化。断裂中生代构活动记录十分详细,可划分为印支期由南向北逆冲、早燕山期左行走滑运动、晚燕山期的旋转运动和喜山期的由北东向南西的逆冲运动。4、燕山东段三组不同方向的断裂系统在中生代发生了不同样式和不同方向的变形,但都属于同一构造背景下的变形,原因是三组断裂形成时代的不一致性,而中生代燕山地区的燕山期变形对印支期变形具有较强的继承性,从而产生了不同样式和方向的变形特征。更多还原

【Abstract】 The Yanshan orogenic belt, which is located at the northern margin of the North China plate, has often been referred to as the cradle of Chinese geology. It is famous among Chinese and foreign geologists from its strong intraplate deformation in Mesozoic and Cenozoic. From the beginning of the last century, many researchers have been done on the geology and tectonics from both Chinese and foreign geologists in this area,many achievement have been acquired, but it was disputed about the deformation sequence and deformation mechanism in eastern segment of the Yanshan orogenic belt in Mesozoic.Since the crystalline basement concreted, many times of different mechanism and direction deformation have been occurred in study area, thrust, extensional tectonics and strike-slip fault have been found on field, such as transmeridional Qinglonghe strike-slip fault, northeast thrust and extensional fault, northwest Lengkou fault. All of the three fault system have been deformed many times since they were formed, the Mesozoic deformation history in the eastern segment of the Yanshan orogenic belt has been recorded in these fault system, so it is worth studying them.The main method of this thesis is structural analysis, through geological surveying, the author disassembled the complex and different scale deformation, analyzed the geometrical, kinetic, dynamic characters, environment, sequence of the structure in study area, then found the evolution, principle and mechanism of the structure in the eastern segment of the Yanshan orogenic belt.The main advancements achieved from the thesis are as followings:1. The northeast thrust formed in early Yanshanian, it caused by the extrusion from northwest to southeast, in the phrase Lijiawopu-sandaohezi fault was formed, the kinetic character of the fault is reverse-right-parallel strike slip. After extrusion, the tectonic environment changed into extension, the Lijiawopu-Sandaohezi fault was extended in some degree, moreover, the stratum in the hanging wall also extended at the same time, though the Mazhuangzi-andashi fault was formed.2. The transmeridional Qinglonghe fault, which formed in Archean, moved again in Mesozoic. In Indosinian its kinetic character was extrusion form south to north; in early Yanshanian was extrusion form northwest to southeast; in late Yanshanian was extension form northwest to southeast. The most obvious record is right-parallel character formed in early Yanshanian.3. The northwest extended Lengkou fault, a special fault is Yanshan belt, was formed during the Yanshan crystalline basement cracking. It moved again in Mesozoic. The movement record of Lenkou fault is very detailed, the movement sequence can be divided into fowling period: thrust form south to east in Indosinian, left-parallel strike slip in early Yanshanian, rotate movement in late Yanshanian, thrust form northeast to southwest in Himalayan.4. The three different direction fault system in eastern segment of Yanshan belt moved in different mode and direction, but the tectonic environment of their deformation is same. The reason is these faults are formed in different age, in Mesozoic they move again followed the primary fault plane, they formed different kinetic characters.更多还原