贺兰山南部构造特征及其与固原-青铜峡断裂的关系

贺兰山南部的变形从经历的时间及方式上与贺兰山中北部有比较明显的区别.从构造和地层等方面论证了固原-青铜峡断裂通过贺兰山的具体地点,该断裂通过贺兰山后逐渐转为东西向;宁夏中部地区东西向构造是古生代弧型构造的一部分,由于后期的改造而成为现今的形式.黄河断裂和固原-青铜峡断裂控制了贺兰山南部的构造发育,由这两断层夹持的块体(卫宁北山)在新生代向东运动,在该块体的东部由于东西向的挤压形成了许多构造,一些山体隆起的原因可能是来自西部卫宁北山向东的挤压.

The tectonic characteristics of southern Helan Mountain and their relationships with the Guyuan-Qingtongxia fault

The duration and processes of deformations in the southern and the central/northern Helan Mountains differ apparently. The location where the Guyuan-Qingtongxia fault crosses the Helan Mountain is determined in light of structures and stratigraphy. After crossing the Mountain the strike of the fault changes into E-W trending gradually. The authors think that the E-W trending structures in the central Ningxia may be a part of the fold-thrust belts which were formed during the early Paleozoic and were modified by later deformation. The Guyuan-Qingtongxia fault and the Yellow River fault controlled the development of the structures in the southern Helan Mountain and the massif (the Weining Beishan) confined by the two faults was moving eastwards in Cenozoic. In the eastern toe of the Weining Beishan the thrusting occurs; the reasons for the uplift of several mountains may lies in the eastward movement of the Weining Beishan.