贺兰山盆地与鄂尔多斯盆地的关系

贺兰山汝箕沟玄武岩形成于晚三叠世末期到中侏罗世末期,属大陆裂谷玄武岩,反映了贺兰山地区当时处于裂谷的沉积环境.贺兰山地区中生代早中期的沉积特征及地层接触关系与鄂尔多斯盆地内部相一致;贺兰山盆地沉积物源、古水流资料及其西麓小松山滑覆构造特征均显示贺兰山盆地是一个更靠近北部边缘、由西向东地势平缓降低的更大沉积盆地的一部分.现今的银川地堑当时也并不是贺兰山盆地与鄂尔多斯盆地的分割.综合分析结果表明,中生代早中期贺兰山地区是鄂尔多斯盆地的一部分.

Relationship between Helanshan Basin and Ordos Basin

Basalt of Rujigou in Helanshan area developed in the terminal period of the Late-Triassic to the late period of the Mid-Jurassic belongs to the continental rift basalt and appeared in the sedimentary basin of rift environment. The sedimentary features and strata touching relation in the Early-middle Mesozoic of Helanshan area were contrast to that of Ordos Basin. The detachment structure, provenance and palaeo-flow direction of Xiaosongshan slip in the west slope of Helanshan also show that Helanshan Basin is a part of a lager sedimentary basin near to the northern margin and topography declined slowly from west to east. The present Yinchuan graben is not the separated line of Helanshan Basin and Ordos Basin. The comprehensive analysis indicated that Helanshan area was a part of Ordos Basin in the Early-Middle Triassic period.