论文部分内容阅读
通过二维、三维地震剖面解释和运用平衡剖面技术观点,对焦石坝地区基底结构、中、古生界构造特征及其构造演化进行了研究。研究结果表明,该区存在着基底卷入和盖层滑脱2种构造类型。基底卷入型有背冲背斜、对冲向斜、叠瓦逆冲、正花状扭动和多字形扭动5种构造样式。盖层滑脱型有断展或断弯、断滑、叠瓦逆冲、叠瓦反冲、冲断楔5种构造样式和组合。燕山早、中期是该区的2个主要构造变形期,在燕山早期,中、古生界与基底及其内幕之间近水平向西拆离滑脱推覆,形成了侏罗山隔挡式背-向斜交替褶皱。方斗山断裂与大天池背斜之间的焦石坝地区为挤压宽缓复向斜背景;在燕山中期,受东邻隔槽带中、深层基底拆离向西强烈冲断作用,焦石坝地区形成了仰冲-逆冲-掩冲构造格局,经历基底叠瓦冲断-盖层滑脱-左行压扭3个变形幕,形成了焦石坝双层背冲背斜及翼部的断褶带。石门断褶带具有多层滑脱褶皱特征,乌江断褶带具有滑脱与左行压扭的性质。构造变形性质与类型、龙马溪组-五峰组滑脱程度、层滑作用产生的构造缝是该区形成大型页岩气田重要的构造影响因素。
Through the interpretation of two-dimensional and three-dimensional seismic profiles and the application of balanced profile technology, the structural characteristics of the basement, Meso-Paleozoic and their tectonic evolution in Jiaoshiba area are studied. The results show that there are two types of structures in this area: basal involvement and cover slip. Substrate involved in the type of back-anticline, hedge oblique, laminated tile thrusting, is the flower-shaped twisting and polygons twist five kinds of structural styles. Caprock slippage with broken or broken bend, broken slip, stacked tile thrust, shingled tile recoil, thrust wedge five kinds of construction styles and combinations. Early and middle Yanshanian are the two major tectonic deformations in this area. During the early, middle and early stages of Yanshan, detachment and detachment from the basement and its inside to the west were separated westward, - Alternating folds of the syncline. The Jiaoanshiba area between the Fangdoushan fault and the Tianchi anticline is characterized by wide and gentle crustal syncline. In the mid-Yanshanian, due to strong detachment of the middle and deep basements in the adjacent sepulcher belt to the west, In the dam area, the Yangdu-Nippon-Neoproterozoic tectonic framework has been formed. Three deformation curtains of the basement fold thrust-cover slip-left twist-compression have been formed. Broken fold belt. The Shimen fault fold belt has the characteristics of multi-layer slip-off fold, and the Wujiang fold belt has the properties of slippage and left-handed compression. The structural deformation caused by the tectonic deformation and type of the Longmaxi Fm and the Wufeng Fm, and the slip caused by the strata slip are the important structural influential factors for the formation of large shale gas fields in this area.