鄂尔多斯地区晚古生代沉积体系及古地理演化

Late Paleozoic Sedimentary System and Paleogeographic Evolution of Ordos Area

采用新的地层划分方案，在野外露头、钻井剖面的综合研究和室内编图基础上，提出陆表海碳酸盐台地—碎屑堡岛—浅水三角洲复合沉积体系是鄂尔多斯地区晚古生代重要的古地理格局。受区域构造背景影响，晚古生代盆地充填经历了裂陷海湾和陆表海浅陷共存、统一陆表海、近海内陆坳陷和内陆湖盆四个阶段，区域古地理格局由陆表海碳酸盐台地—碎屑堡岛—浅水三角洲复合体系沉积演变为三角洲—河流体系沉积，最终被河流—湖泊体系沉积取代。砂质储集体发育受控于沉积环境，主要展布在中、北部地区，以河流、三角洲砂体为主。

Based on the synthetic study of field outcrops and drilling section data, and using new stratigraphic division program, this paper proposes that the paleogeographic pattern of Ordos area was the compound sedimentary system of epiric sea carbonate platform clastic barrier island shallow water delta. Influenced by aeral tectonic background, the late Paleozoic basin filling included four stages from the filling of the rift bay basin coexisting with shallow rifting epiric sea, the filling of epiric sea, the filling of paralic inland sea to the filling of inland lake depression.The evolution of areal paleogeographic pattern was from the compound system deposition of epiric sea carbonate platform clastic barrier island shallow water delta to delta fluvial system deposition and at last the fluvial lake system deposition.The development of sandy reservoir body was controlled by sedimentary envoronments. The sand bodies mainly distribute in the central and northern parts of Ordos area, and mainly the fluvial delta sand bodies.