Deformation Features and Modeling Experiments of Nappe/Decollement Structure in Xuefeng Mountain Intracontinental Orogenic Belt
雪峰山陆内造山带变形特征及挤压推覆—伸展滑脱构造的物理模拟

In this paper, the authors have analyzed the deformation features of Xuefeng Mountain intracontinental orogenic belt, and pointed out that Xuefeng Mountain orogenic belt was developed on the basis of the marginal rifted depressive trough of the craton, and experienced Caledonian pre-orogenic epicontinental folding, main orogenic epoch in Indosinian-Yanshanian movement, re-orogenic epoch in late Yanshanian-early Himalayan movement. From Mesozoic, the lithosphere subducted northwestward and the crust was compressed westward. The base surge and nappe were formed and thickened in middle-upper crust. The twin-polarity gravity surge was formed on each side of the orogenic belt during laxity and extension. The model experiment of nappe/decollement structure was done, and the result indicates that the pressure from southeast was the major stress that formed the nappe/decollement structures. The extension structures was formed at the stage of relaxation.