【摘要】 大别山造山带作为三叠纪华北与扬子大陆碰撞成因并形成超高压变质岩石已经没有异议。然而,对侏罗纪的变形性质和大地构造背景的认识还未取得一致意见。通过前陆早侏罗世地层褶皱,前陆深部反射地震探测,造山带内 SE 角闪岩相线理变形以及160～120Ma 岩浆岩记录和同位素年代学研究等新的研究成果,证实中侏罗世大别山曾发生强烈的造山运动。这次造山运动相当于“燕山运动”,由于扬子与华北陆块在三叠纪已经拼合成一个大陆,所以侏罗纪变形属于陆内造山性质。将侏罗纪变形事件从大别山碰撞造山过程中分离出来可以合理地解释大别山超高压岩石第二次折返(从壳幔边界到地壳浅部)机理,150Ma 的混合岩化作用和广泛的130～120Ma 花岗岩-火山岩成因,以及大别山前陆 MOHO 错断等现象。更多还原

【Abstract】 It was widely accepted that the Dabie orogen underwent an ultrahigh-pressure metamorphism as a result of the Triassic collision between the North China and Yangtze continents.However,there has been much debate on the deformation within the orogen and tectonic setting during the Jurassic.The study on the folding of the pre-Jurassic strata and deep reflection seismic exploration in the foreland belt,the SE deformation of amphibolite facies in the high- and ultrahigh~pressure rocks,and the igneous records of 160～120 Ma in the orogen suggest that a strong orogeny took place in the Dabie Mountains in the middle Jurassic.The orogeny was related to the Yanshanian movement.Because the North China and Yangtze blocks have collided and formed an uniform continent in Triassic,the Jurassic deformation was of intra-continental origin.A separation of Jurassic deformation from the Triassic collisional process of the Dabie Mountains could reasonably explain the second exhumation of ultrahigh-pressure metamorphic rocks from the mantle-crust boundary to the upper crust,the genesis of migmatization at 150 Ma and magmatic activity at 130～120 Ma,and the offset of MOHO in the Dabie foreland belt.更多还原