西昆仑山前柯东构造带变形特征、机制及物理模拟

摘要

柯东构造带地处西昆仑造山带前缘，构造演化受到西昆仑山隆升的重要影响，变形主要发生在新近纪-第四纪。地震资料显示，该区深部变形以逆冲叠瓦断层的发育为特点，浅部为一套北倾新生界地层为主的单斜层。采用构造物理模拟方法对柯东构造带的构造变形演化过程和变形机制进行了分析，研究结果表明，柯东构造带变形主要受由南往北的区域挤压、剥蚀作用、同构造沉积作用等因素影响。古近系膏岩层和侏罗系煤系地层组成的区域上的复合滑脱层，控制了该区深浅构造脱耦与差异性演化。%The Kedong structure locates in the front of the western Kunlun orogenic belt and was impacted signi-ficantly by the uplift of the western Kunlun Mountain. Deformations took place mainly in Neogene and Quaterna-ry. Seismic data showed that the deformations in deep series were featured by thrust and imbricate faults, while in the shallow series a set of Cenozoic monoclines inclined to the north developed. The structural deformation process and mechanism of the Kedong structure were analyzed with physical simulation. It was concluded that the Kedong structure was mainly controlled by compression from south to north, erosion and synkinematic sedimenta-tion. Paleogene evaporate bed and Jurassic coal-series stratum worked as regional composite detachment and con-trolled the decoupling and differential evolution of the upper and lower structures.