川东南褶皱带西山背斜构造解析与运动学模拟

以高信噪比地震资料为基础，运用断层相关褶皱理论对西山背斜构造变形特征进行几何学构造解析，提取构造特征参数，基于构造三角楔和断层转折褶皱的计算机模拟，对西山背斜的构造几何变形进行运动学模拟。模拟结果表明，西山背斜分为浅层、中层和深层构造，浅层构造受晚燕山运动—喜马拉雅运动的影响，形成于白垩纪至全新世，下三叠统嘉陵江组底部滑脱层之上发育的突破断层控制浅表构造变形；中层构造受印支运动的影响，形成于早三叠世到晚三叠世，发育构造三角楔和断层传播褶皱；深层构造受加里东—海西运动影响，发育滑脱褶皱。印支运动形成的构造楔、反冲断层和晚燕山运动—喜马拉雅运动形成的逆冲断层及后期遭受剥蚀等共同作用下，最终形成现今的构造格局。

Structural Analysis and Kinematics Simulation of Xishan Anticline in Southeast Folded Belt,Sichuan Basin

Based on the seismic data of high signal?to?noise ratio, this paper presents the structural geometry analysis of the structural deformation feature and characteristic parameters in Xishan anticline by means of fault?related folding theory and the kinematic simulation of the geometry deformation in terms of structural wedge and fault propagation fold modeling. The results show that Xihan anticline can be divided into shallow structural layer, middle structural layer and deep structural layer. The shallow structural layer was influenced by Late Yanshan-Himalayan orogenic movements and formed at the beginning of the Cretaceous and ended in the Holocene. The shallow structural deformation was controlled by the breakthrough fault developed on the bottom detachment of the Jialingjiang formation. The middle structure was influenced by Indosinian movement, shaped in Early Triassic and ended in Late Triassic, with structural wedge and fault?propagation fold. The deep structure was influenced by Caledonian movement and formed detachment fold. The Indosinian structural wedge and recoil faults, the Late Yanshan-Himalayan thrust faults and late denudation are the factors for the present tectonic framework in Xishan area