Abstract:

Mesozoic sedimentary basins in North China are mainly single-cycle ones in small or medium size.The formation of the basins underwent multi-stage evolution accociated with volcanic activities and their distribution appears to be in groups and zones.The north and east part of the region uplifted during the Middle Triassic,lacustrine basins that connected to the Ordos Basin formed only in Late Trias-sic in west Henan and south Shanxi.The whole region uplifted in the latestage of Indosinian movement.In the Early and Middle Jurassic,18 basins which were small in size and contained mainly coal scattered in the mobilebelt around the uplift.In Late Jurassic-Early Cretaceous,the depocentcr movedeastward,and the area of deposition extended and dark sequences were well developed.This was the most prosperous period in the evolution history ofthe Mesozoic basins and the basin number was up to 41.Since Late Creta-ceous,basins were not developed well,and only 14 basins left.The sedimentswere generally red clastic rocks.Till now 60 sedimentary basins or residual blocks have been found withinthe area.They can be divided into 6 kinds of proto type basins,i.e.depres-sion,piedmont depression,fold-depression,fault-depression,intermontanefault-depression and fault-depressed volcanic types.They are distributed in 10 regions,west Liaoning,Shijiazhuang-Linqing,Shenqiu,west Henan and Laiyang among these regions are considered to be oil potential areas.