摘要
沉积盆地的形貌、充填及变形受区域大地构造的影响和控制。北京西山侏罗纪盆地是在三叠纪末开阔谷地的基础上发展起来的。三叠纪末或早侏罗世初,开阔的谷底沉积了山间河流相的杏石口组。早侏罗世中期,盆地被溢流和喷发的南大岭组玄武安山岩充填。北京西山侏罗纪盆地早期沉积是恢复其原型盆地的重要依据。中侏罗世早期是全区重要的成煤期,下窑坡组为湖泊—三角洲及沼泽相。中侏罗世中期,北京西山盆地逐渐封闭,上窑坡组上部沉积已经在宁静中孕育着风暴。中侏罗世中-晚期,燕山运动主幕强烈爆发,盆地在接受了龙门组粗碎屑快速充填后,开始在九龙山期分化,盆地沉积中心向北迁移,在晚侏罗世期间消亡。北京西山侏罗纪盆地的演化及其变形的动力学背景与西伯利亚地块和华北地块在中—晚侏罗世的碰撞拼合密切相关。
The landform,filling and deformation of sedimentary basins are influenced and controlled by tectonics.The Jurassic basin of the Western Hills,Beijing,developed on the basis of an open valley at the end of the Triassic.At the end of the Triassic or at the beginning of the Early Jurassic,the intermontane fluvial Xingshikou Formation was deposited on the bottom of the open valley.In the middle Early Jurassic the basin was filled up by the flood and eruptive basaltic andesite of the Nandaling Formation.The early-stage deposits in the Jurassic basin is the key evidence for the reconstruction of the prototype of the basin.The early Middle Jurassic was an major coal-forming period in the region,when the Lower Yaopo For-mation of lacustrine-deltaic and swamp facies was deposited.In the middle Middle Jurassic the basin was gradually isolated and the upper part of the Upper Yaopo Formation was about undergoing a strong move-ment.In the mid-late Middle Jurassic the main phase of the Yanshanian movement took place strongly,and the basin started to be differentiated in the Jiulongshanian stage after it was rapidly filled by coarse fragments of the Longmen Formation.The depocenters of the basin shifted towards the north.In the Late Jurassic the basin was eliminated.The dynamic background of the evolution and deformation of the Jurassic basin of the Western Hills of Beijing were the collision and assembly of the Siberian block and North China block in the Mid-Late Jurassic.
出处
《地质通报》
CAS
CSCD
北大核心
2002年第4期211-217,共7页
Geological Bulletin of China
基金
中国地质调查局地质大调查项目(DKD2001008)
国家自然科学基金重点项目(40132020)资助。
