中国东部燕山期高原的发育及对矿产和油气资源评价的启示

作者首次提出苏皖地块是特提斯演化阶段一个独立的构造单元。基于火成岩及变质岩和古地磁的研究成果认为苏鲁洋在晚侏罗—早白垩世最终闭合,苏皖地块与华北克拉通碰撞而出现高原,因而中国东部燕山期高原性质上应属碰撞高原。文中还讨论了高原边缘的冲断-推覆带和其内部的复杂结构(包括沿主碰撞-剪切带发育的相对高峻地带和相对开阔的山间磨拉石盆地),认为该高原是规模宏伟的东亚燕山造山系中变形变质相对弱的部分。高原自早白垩世末起坍塌,晚白垩世是东亚燕山造山系的全面坍塌期,第三纪时燕山期高原已不复存在。

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.