【作者】 赵保强；

【导师】 张维杰；

【作者基本信息】 中国地质大学（北京） ， 构造地质学， 2010， 硕士

【摘要】 多禾茂地区位于青藏高原东北缘,作为印度-欧亚大陆碰撞的一种响应,青藏高缘东北缘自中生代以来发生了一系列的构造活动,这些构造活动的发生对多禾茂地区南北向断裂系的形成和发展起到了重要的作用。多禾茂地区南北向断裂系位于青海省泽库县,属于西秦岭造山带,该断裂在区内长度约20Km,主要由4条断裂组成,分布在多禾茂乡东西两侧,断裂总体倾向西,局部受挤压断面发生弯曲倾向东,倾角较陡。南北向断裂系控制了玄武岩和紫红色砂砾岩的分布,是多福屯盆地重要的控盆断裂。南北向断裂是在白垩纪南北向挤压应力的背景下形成的,本论文通过野外地质填图、剖面测量等工作,系统的分析了南北向断裂的几何学、运动学和动力学特征;划分出该断裂的形成期次:第一期为正断层,第二期为逆冲断裂,第三期为逆冲断裂再次活化期;阐述了该断裂的形成演化及其与青藏高原隆升的关系。通过野外观察,南北向断裂为多福屯盆地的控盆断裂,多福屯盆地中玄武岩与紫红色砂砾岩互层分布,我们可以判断该断裂第一期次跟玄武岩在同一时期形成或略早。结合前人对该地区玄武岩测年数据及对青藏高原东北缘隆升的研究,推断该断裂第一期正断层形成时代为早白垩世,112Ma左右;第二期,逆冲断裂形成于白垩纪末,新近纪初;第三期发生在上新世,3.6Ma左右。更多还原

【Abstract】 Duohemao region locate in northeastern Tibetan Plateau, As the response to the collision between the Indian and Eurasian plates, a series of tectonic action was taken place in northeastern Tibetan Plateau after Mesozoic , which play a important role in the formation and evoiution of the S-N fault system in the Duohemao region.The S-N fault system Duohemao region lies in Zeku surname of Qinghai province, which is along to the western Qinling tectonic regimes. The fault system is 20 kilometers long, it includes four chief faults, which is located in east and west sides of Duohemao town. It dips to the west, part dip to east for the press force, the dip angle is rather steep. The fault controls the distribution of basalt and purple glutenite, and is the important fault controlling the basins of Duofutun.The S-N fault system is formed in the Cretaceous NS compressive stress tectonic settings of the west Qinling. The paper analyze the fault’s geometry, kinesiology, dyn features in detail; divided the fault into three cycles: the first one is normal fault, the second is reverse fault; and the third is the reverse fault become active again; expatiate the formation and evolution of this fault as well as the relations with the uplift of Tibetan Plateau by the means of field mapping and profile survey etc.Form the field observation; the faults control the formation and evolution of Duofutun Basin, and basalt interbed with purple glutenite in Duofutun Basin, so we can deduce that first phase of the faults with the formation of basalt in the same period or slightly earlier. Combining with the former research of dating data to the basalt in this region and the uplift of the north-east edge of Tibetan Plateau we can deduce the time of the normal fault formation is Early Cretaceous, about 112 Ma, and the reverse thrust take place in the Eocene,the third occur in the Pliocene.更多还原