关键词: 鄂尔多斯盆地, 前陆盆地, 古生界, 中央古隆起, 成因, 油气分布

Abstract: The Ordos Basin,one of the large composite and hydrocarbon-bearing asins,is located in the western part of North China plate. The large-scale oilfield of the Mesozoic has been found in the first cycle of exploration.In the second cycle, the study on the Paleozoic has achieved breakthrough and high-speed progress.The transitional environmental detrital rocks broadly distributed in the Late Paleozoic and the marine environmental carbonaceous halite developed in the Early Paleozoic and Middle Proterozoic are all the excellent hydrocarbon source rocks.The weathering crust of the Caledonian has the advantage of the natural gas accumulation.The western and southern margins of the Ordos Basin are the passive continental margins developed on the basement of the Proterozoic three-fork rift of Qin(ling)-Qi(lian)-He (lan) area and gradually developed as the active continental margins.From the Middle Ordovician (O₂) to the Middle Carboniferous (C₂), Qin(lin)-Qi(lian) ocean troughs were subducted and collided to the directions of east and north. Therefore,the Paleozoic foreland basins were formed,and its forebulges were changed into "L-shape" of central paleouplift in the plane.The western margin thrust belts,the south-ern margin thrust belts and the central paleouplift are all the favorable areas for oil and gas exploration of the Paleozoic.

Key words: Ordos Basin, foreland basin, paleozoic, central paleouplift, hydrocarbon migration and accumulation