NEW PROGRESS IN THE STUDY OF TECTONIC GEOMETRY OF THE NORTH YELLOW SEA BASIN

The North Yellow Sea basin is a Meso-Cenozoic sedimentary basin developed in the setting of the Jiaoliao uplift.Study indicates that the basement of the Meso-Cenozoic North Yellow Sea basin consists of Paleozoic sedimentary rocks and Precambrian metamorphic rocks,and that the basin is developed to different degrees in the lower(J₃-K₁),middle(E₂-E₃) and upper(N) tectonic layers.Based on petroleum resources and Meso-Cenozoic strata,the North Yellow Sea region may be divided into three first-order tectonic units,namely,the Liaodong-Haiyangdao uplift area,North Yellow Sea basin and Jiabei-Liugongdao uplift area.Of these tectonic units,the North Yellow Sea basin includes six second-order tectonic units and 24 third-order tectonic units.Folds and faults are very well developed in the basin.The former may be divided into regional compressive folds,local associated folds and drape-like folds,and the latter mainly includes the nearly EW-NE set,NW set and NNE set,of which the nearly EW-NE and NNE sets of faults are better developed and control the distribution pattern of uplift and depression and sedimentary features.