OCCURRING OF THE EAST CHINA YANSHANIAN PLATEAU AND ITS INSPIRATION TO MINERAL AND PETROLEUM RESOURCES EVALUATION

It is first represented that the Su-Wan(Jiangsu-Anhui)Block is an independent tectonic unit in the period of Tethyan evolution.Based on the research fruits of igneous rocks,metamorphic rocks and paleogeomagnetism,it is thought that the Su-Lu(Jiangsu-Shandong)Ocean closed in the Late Jurassic-Early Cretaceous at last,the collision of the Su-Wan Block with the North China Craton resulted in the appearance of the plateau,and the East China Yanshanian Plateau should belong to collision plateaus in its features.In this paper,the thrust-nappe zone on the margin of the plateau and its internal complex structure,including relative high and steep spaces developing along major collision-shear zones and relative open intermountain molasse basins,are also discussed.It is considered that the plateau is a part of the grand scale East Asia Yanshanian Orogenic Series with relative weak deformation and metamorphism.The plateau had collapsed since the end of the Early Cretaceous.The Late Cretaceous was the overall collapsing period of the East Asia Yanshanian Orogenic Series.In the Tertiary,the Yanshanian plateau did not exist at all.Strong magmatic activities made Yanshanian mineralization possess obvious regional specialization not only in Su-Wan area but also in Jiaodong,Xiaoqinling and Northeast Jiangxi areas.The Late Mesozoic-Cenozoic tectonic events resulted in the low strength lithosphere and high geothermal gradient in Su-Wan to the Huanghai Sea area.On this basis,the petroleum prospects are evaluated.