位于华北地块南缘与秦岭造山带北侧的关中地区，在新生代形成一个新的沉积盆地，即渭河盆地，是汾渭裂谷系的一部分。本文在野外考察研究并且充分调研前人各方面的研究成果与资料，运用构造地质学、大地构造等相关学科的理论与方法，对渭河盆地及相邻构造带的地质构造特征进行了研究。同时，在此基础上，探讨了渭河盆地的形成机理等相关问题。渭河盆地发育一系列近于东西走向的阶梯状陡立正断层，略向盆地（地堑）中轴方向倾斜，构成一地堑构造和盆地的主要构造格架。在渭河以北（包括渭河河谷）地区，在近E—W方向上，表现最为显著的有3条断裂带：从北向南，分别为经过天度镇南侧、马嵬镇和渭河河谷的断裂带。这些断层在地形地貌上表现阶地式的陡坎，其中尤以通过马嵬镇一带的断裂带的地形高差最大，正断层的地貌特征最为显著。这些阶地式的陡坎恰与盆地内部第三系底界中发育的台阶状陡坎或正断层相对应，是此类正断层存在与活动的反映。这些正断层不仅具有同生断层的特征，而且控制了盆内新生界的沉积。渭河盆地有高的大地热流值、莫霍面上隆等特征，表明其深部软流圈上涌，地幔隆起，导致地壳减薄，这与华夏裂谷系具有相似性。软流圈物质可能上涌，直接导致莫霍面的上隆以及上部地壳的拉伸减薄，形成地堑构造。因此，表明渭河盆地为一典型的裂谷盆地。通过以上研究表明，包括渭河盆地在内的整个汾渭裂谷系，是在地幔隆起和上部地壳水平方向上的顺针向剪切作用的双重或联合作用下所形成的。渭河盆地南部为秦岭造山带，北部为鄂尔多斯盆地的渭北隆起，其形成演化和构造特征受两者构造演化影响显著。通过野外考察，发现在秦岭构造带的北边缘，压性、压扭性的断层发育，各种挤压构造现象发育，显示了秦岭构造带以向北为主的推挤或压扭性作用。通过对渭北隆起的构造特征观测以及隆起形成演化特征进的研究，表明其形成可能与渭河盆地的形成和活动有关。

Located in the Guanzhong area in the south rim of north China block and north side of the Qinling orogenic belt, a new sedimentary basin formed in the Cenozoic, namely Weihe Basin, which is a part of the Fenwei rift system.On the basis of field surveys, this paper conducts full investigation of the previous research achievement and materials and applies theories and methods of relevant subjects such as structural geology, geotectonics to the research of characteristics of geological structure of Weihe Basin and adjacent structural belts. On this basis, this paper discusses the formation mechanism and other relevant issues.Weihei Basin developed a series of step ladder like steep normal fault zones in near E-W direction, which inclining slightly to the medial axis of the basin (graben), forming the main tectonic framework of graben structure and basin.It is found by field surveys and measurement that there exist 3 obvious fault zones in the near E-W direction in the north Weihe region (including Weihe Basin): From north to south, it covers fault zones of south Tianduzhen, Maweizhen and Weihe Basin respectively. These fault zones take on terrace scarp as to topography and geomorphology, the terrain height difference of the fault zones through Maweizhen is especially large, showing geomorphological characteristics of obvious normal fault zones. These step ladders like scarps are coincidently correspondent to terrain like scarp developed within the basin in Tertiary System, which is the evidence for the existence and activities of these kinds of normal fault zones. These normal fault zones not only have the features of contemporaneous faults, but also controls the sedimentation within the basin in the Cenozoic.Weihe Basin has the characteristics of high terrestrial heat flow and uplifted Moho and etc, indicating upwelling of the deep asthenosphere and the uplifting the mantle which results in thinned crust, much resembled to the features of cathaysian rift system.The asthenosphere substance may upwell, resulting in the Moho uplifting and crust thinning and forming graben structure. Therefore, Weihe Basin is a typical rift basin.In the south of Weihe Basin is the Qinling orogenic zone and in the north is the Weibei Uplifting of the Ordos Basin, therefore the formation evolution and the structural characteristics are greatly influenced by the structural evolution. By field surveys, it is found that compressive fault zones, twist-compression fault zones and various compressional structure phenomenons are developed along the north rim of the Qinling structural belt, demonstrating that broaching or twist-compression to the north of Qinling structural belt. The research of structural feature observation of the Weibei Uplifting and the formation evolution features of the uplifting indicate that it may be related to the formation and activities of Weihe Basin.The above research shows that the whole Fenwei rift system, including Weihe Basin, is formed under the double or combined effects of the mantle uplifting and clock-wise shearing of the upper crust in the horizontal direction of the crust.