通过对三叠系不同组段顶面构造图分析和主干地震剖面解释,认为川西坳陷孝泉-丰谷构造带具有走向分带、垂向分层变形特征.该构造带走向上可划分为孝泉、新场、合兴场、丰谷等4排北东东向雁列式滑脱褶皱带,与合兴场-石泉场近南北向背斜构造带近直交;垂向上以雷口坡组内膏盐层为界分上、下两个构造层,上部构造层发育滑脱断层及其相关的褶皱构造,下部构造层产状平缓,断层、褶皱构造不发育.多组平面、剖面模拟实验结果表明:孝泉-丰谷北东东向滑脱褶皱带可能是在龙门山褶皱隆升产生的北西向挤压应力和秦巴山系褶皱隆升产生的近南北向挤压应力联合作用下形成的;合兴场-石泉场近南北向构造带可能是在北西方向的应力单独挤压作用下形成的;雷口坡组内膏盐层在空间上不均衡分布是产生走向分带、垂向分层变形的主控物质因素.%Based on structure maps of top surface of different members in Triassic Formation and typical profile interprtation, the deformation characteristics in Xiaoquan-Fenggu structural belt are regarded as horizontal zonation and vertical lamination. NNE trend structure belt that is vertical to the SN trend anticline belt of HexingchangShiquanchang includes Xiaoquan anticline, Xinchang anticline, Hexingchang anticline and Fenggu anticline. Upper and lower structural layers have been divided on the basis of gypsum rock within Leikoupo Formation. Decollent faults and related folds that formed anticline trap developed in the upper layer, and fault-related fold did not develop in the lower part. According to the analyses of simulation result, main control factors of deformation since Mesozoic Era are the compress stress from two sides and non-homogeneous decollement layers. Four conclutions have been drawn as follow: ①strike zonation and vertical lamination is the typical deformation style in the study area; ②NEE detachment fold-fault system developed in the early-middle period of Yanshan Movement in Xiaoquan-Fenggu structural belt, which was controlled by combination process of compress stress from Longmenshan in the west part and Dabashan in the north part; ③SN anticline belt of Hexingchang-Shiquanchang which superimposed in XiaoquanFenggu structural belt was controlled by the compress stress coming from Longmenshan from Late Yanshan Movement to Himalayan Movement; ④ plane and profile simulation results indicate that non-homogeneous distribution of gypsum rock located on the bottom of Leikoupo Formation may be the main material factor to cause horizontal zonation and vertical lamination.
展开▼
