秦岭-大别造山带北缘新生代的构造特征及动力学探讨  

Cenozoic structures and dynamics on the northern margin of the Qinling-Dabie orogenic belt

作　　者：宋传中[1] 刘国生[1] 牛漫兰 王道轩 朱光 

机构地区：[1]合肥工业大学,安徽合肥230009

出　　处：《地质通报》2002年第8期530-535,共6页Geological Bulletin of China

基　　金：国家自然科学基金重大项目(49290100);国家自然科学基金项目(49872074)共同资助。

摘　　要：秦岭-大别造山带北缘新生代的推覆构造带位于宜阳、鲁山、确山、六安一线,由SW→NE依次逆冲叠置。滑脱面主要发育在上古生界软弱岩层或差异岩性的接触面上。在推覆构造的南侧,发育有东西向串珠状分布的变质核杂岩、NE向延伸的垒-堑构造组合、北宽南窄的楔形新生代盆地和正断层等。地球物理资料表明,宜阳、鲁山、确山、六安一线为向南倾斜的地球物理异常带。北部的华北地壳与南部的秦岭-大别地壳在视电阻率、地震反射波组、地震波速、流变学分层、地壳类型和岩石圈结构等方面,均有明显的差别。秦岭-大别造山带北缘新生代不同性质、有规律展布的构造,是中生代末期以来,华北板块相对于秦岭-大别造山带作巨型陆内俯冲的结果。The Cenozoic nappe structure zone on the northern margin of the Qinling-Dabie Mountains lies along the Yiyang-Lushan-Queshan-Liu'an line.The nappes were thrust and stacked each other succes-sively from SW to NE.The shortening rate is52%.The detachment surface is developed mainly on the upper Paleozoic beds of weakness or on the contact surface between differential lithologies.The E-W-trending bead-like metamorphic core complex,horst-graben tectonic combination stretching in a NE di-rection,wedge-shaped Cenozoic basins narrowing southward and normal faults are developed on the southern side of the nappe structure.Geophysical data indicate that the Yiyang-Lushan-Queshan-Liu'an line is a south-dipping geophysical anomaly zone.There are appreciable differences in apparent resistivity,seis mic reflection series,seismic wave velocity,rheo logical stratification,type of crust and lithosphere structure between the crust of North China in the north and the crust of the Qinling-Dabie orogenic belt in the south.The structures of different natures and regular distribution on the northern margin of the Qinling-Dabie orogenic belt in Cenozoic are the result of large-scale intracontinental subduction of the North China plate relative to the Qinling-Dabie orogenic belt since the end of the Mesozoic.

关 键 词：动力学 秦岭造山带 大别造山带 华北板块 新生代 陆内俯冲 

分 类 号：P542.2[天文地球—构造地质学]