摘要
华北地台北缘乌兰哈雅地区发现二叠纪未—三叠纪初蒙古寺—盘羊山—乌兰哈雅推覆构造,将晚太古代色尔腾山岩群绿片岩系推覆到震旦系什那干组灰岩和古生代碎屑岩系之上。推覆面走向近东西向,延伸长度大于50km,推覆方向180～230°,推覆距离大于4.5km。推覆界面被中三叠世(U-Pb同位素年龄231Ma)二长花岗岩侵入,又被中侏罗统大青山组不整合覆盖。本推覆构造的发现改变了前人认为本区不存在古生代末大型推覆构造的看法,对了解华北地台(板块)构造发展历史与地壳演化有重要意义。说明华北地台(板块)晚古生代末存在大型陆内造山事件,其动力来源推测为华北板块与华南板块的碰撞所产生的巨大挤压应力。
The Latest Permian -earliest Triassic Menggusi-Panyangshan -Ulan Haya nappe structure was found in the Ulan Haya area on the northern margin of the North China platform.The greenstone series of the Neo-archean Serteng Mountain Group-complex is thrust over the limestone of the Sinian Shinagan Formation and Paleozoic clastic series.The thrust surface strikes in a nearly E-W direction with an exten-sion length of >50km,the vergence of thrusting is180-230°and the displacement is>4.5km.Middle Triassic(U-Pb age231Ma )monzogranite intrudes along the thrust surface and is in turn overlain uncon-formably by the Middle Jurassic Daqingshan Formation.The discovery of this nappe structure changes the previous view that no latest Paleozoic large-scale nappe structure exists in the area and has great signifi-cance in understanding the tectonic development and crustal evolution in the North China platform(plate).This implies that a large -scale intracontinental orogenic event occurred in the North China platform(plate)in the terminal Late Paleozoic and it is inferred that its dynamic source was derived from tremen-dous compressional stress produced by the collision between the North China plate and South China plate.
出处
《中国地质》
CAS
CSCD
2002年第2期135-138,共4页
Geology in China
