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秦岭—大别造山带横贯中国大陆中部,并将我国东部分为南北两部;即华北克拉通和扬子克拉通.在南、北相向运动力系驱动下构成了一个极为复杂的复合、叠加构造带、成矿带和地震活动带.同时导致了该地域异常变化的沉积建造和强烈起伏的结晶基底.然而对它们形成的地球物理边界场响应,岩相和结构的异常变化尚不清晰,特别对盆山之间的耦合响应更缺乏深层动力过程的理解.为此本文通过该区榆林—铜川—涪陵长1000km剖面的地震探测和研究结果提出:(1)沉积建造厚度变化为4~10km,结晶基底起伏强烈,幅度可达4~6km;(2)一系列基底断裂将该区切割为南鄂尔多斯盆地和秦岭北缘前陆盆地、秦岭—大巴造山带和南缘前陆盆地与东北四川盆地,其中前陆盆地为秦岭北渭河盆地和秦岭南通江—万源盆地;(3)秦岭造山带是北部华北克拉通向南推挤、南部扬子克拉通向北推挤下隆升的陆内山体,并构筑了其南、北前陆盆地;(4)秦岭造山带的南、北边界并非是一条边界断层,而应是包括前陆盆地在内的组合界带;(5)秦岭与大巴弧形山系源于同一深部结晶基底,即同根生.这一系列的新认识对深化理解秦岭—大巴造山带形成的深层动力过程和演化机理及厘定扬子克拉通的真实北界具有极为重要的意义.
The Qinling-Dabie orogenic belt traverses the central part of mainland China and divides the eastern part of our country into two parts: the North China Craton and the Yangtze Craton, which constitute an extremely complex composite and superimposed structure driven by the facies forces of the south and north facies Belt, metallogenic belt and seismic belt.At the same time, the sedimentary construction and the strong undulating crystalline basement with abnormal changes in the area have resulted in the abnormal changes of lithofacies and structures in response to the geophysical boundary fields formed by them The coupling reaction between the basin and the mountain lacks the understanding of the deep dynamic process.Therefore, based on the seismic exploration and research results of the 1000km long section of Yulin-Tongchuan-Fuling in this area, the paper presents: (1) The thickness of the sedimentary deposit varies from 4 to 10km, (2) A series of basement faults cut the area into the foreland basin in the South Ordos Basin and the northern Qinling Mountains, the Qinling-Daboba orogenic belt and the southern foreland basin and the northeast Sichuan Basin, Among them, the foreland basin is the North Weihe Basin in the Qinling Mountains and the Nantongjiang-Wanyuan Basin in the Qinling Mountains. (3) The Qinling orogenic belt is pushed northwards in the North China Craton and southwards in the Yangtze Craton. (4) The north and south boundaries of the Qinling orogenic belt are not a boundary fault, but should be a combination of belt including the foreland basin (5) Qinling and Daoba argillaceous originated from the same deep crystalline basement, that is, the same root.These new understandings are of great significance for deepening the understanding of the deep dynamic process and evolution mechanism of the formation of the Qinling-Daba Orogenic Belt and determining the truth of the Yangtze craton The northern boundary is of great importance.