鄂尔多斯盆地西缘北段中生代构造演化

Mesozoic Tectonic Evolution in North Section of the Western Margin of Ordos basin

鄂尔多斯盆地西缘构造带处于独特的大地构造位置,具有复杂的构造特征。长期以来,不同学者对北段构造特征和属性、构造演化和形成机制等开展了大量的研究工作,观点不尽相同。本文在系统研究西缘北段构造带几何学的基础上,通过沉降史分析与岩石类型分析等方法,对其运动学进行解释。研究认为西缘构造带的冲断活动以及盆地的沉降与青藏高原地体增生事件以及伊泽奈琦板块的俯冲关系非常密切。盆地西缘南北向逆冲推覆带在晚三叠世——白垩纪时期内构造基本定型,相应的西缘发育陆内前陆盆地,并发育多套同构造的粗碎屑的沉积。

For a long time, many scholars have made a lot of studies on the structural characteristics, attributes, evolution, and formation mechanism of the north part of the western Ordos basin because of its special tectonic location and complex structural features, they are different viewpoints. In this paper, based on the study on the northern zone geometry, with the subsidence history and rock type analysis, kinematics of the northern zone has been interpreted. It is concluded that the thrusting activity of Western structural belt and subsidence of the basin were closely related to the terranes accretion of Qinghai-Xizang （Tibetan） Plateau and the subduction of Izanagi plate. The NS- striking thrust-nappe belt along the western Ordos basin was come into being in Late Triassic-Cretaceous, accordingly, intracontinental foreland basin was developed in western basin and Multiple syntectonic coarse fragment were deposited.