四川盆地乐山—龙女寺古隆起地质结构及构造演化  

Geologic structure and tectonic evolution of Leshan-Longnvsi paleo-uplift in Sichuan Basin,China

作　　者：梅庆华[1] 何登发[1] 文竹[1] 李英强[1] 李皎[1] 

机构地区：[1]中国地质大学能源学院,北京100083

出　　处：《石油学报》2014年第1期11-25,共15页Acta Petrolei Sinica

基　　金：国家自然科学基金重点项目(No.40739906);国家重大科技专项(2011ZX05008-001)资助

摘　　要：乐山-龙女寺古隆起位于四川盆地中西部,紧邻龙门山构造带。古隆起的地质结构及构造演化对陆内变形和油气勘探具有重要的意义。利用最新的高分辨率地震和探井资料,结合盆地周边的露头资料,对乐山-龙女寺古隆起的地质结构进行了研究。其结果显示:乐山-龙女寺古隆起地质结构在整体上构造变形较弱,仅在龙门山前和龙泉山地区变形相对较强;剖面上存在多套滑脱层,具有上、下分层变形特征。通过地震剖面精细解释,并利用平衡剖面技术,分析了古隆起的构造演化。研究认为乐山-龙女寺古隆起受基底隆起控制、具有一定继承性,经历了多期同沉积隆起兼剥蚀过程,形成于前二叠纪,随后经过印支运动、燕山运动及喜马拉雅运动的调整改造最终定型;其构造演化经历了雏形阶段、发展阶段、强烈隆升剥蚀阶段、稳定埋藏阶段、川西前陆盆地发育阶段以及调整定型阶段,主要受基底和分层滑脱系统2方面因素的影响。The Leshan-Longnvsi paleo-uplift is located at the mid-west of Sichuan Basin, adjacent to the Longmen mountain tectonic belt. The geological structure and tectonic evolution of Leshan-Longnvsi paleo-uplift plays a significant role in intraplate deformation and exploration of oil-gas resources in this region. In this study, the geological structure of the paleo-uplift is analyzed using the lat- est high-resolution seismic data and well data of Sichuan Basin combined with the data of outcrops around the basin. Results show that the intensity of tectonic deformation in the present geological structure of Leshan-Longnvsi paleo-uplift is overall weak, except at the front of Longmen mountains and in the Longquan mountains; there are multiple sets of detachment layer with different structural deformation in the vertical profile. Additionally, the tectonic evolution of the paleo-uplift is discussed based on fine interpretation of seismic profiles combined with the balanced section technique. Evidence shows that Leshan-Longnvsi paleo-uplift, as controlled by basement uplift and with a certain inheritance, has experienced multiple stages of synsedimentary uplifting and erosion; it was formed in the pre-Permian period and then deformed by the Indosinian, Yanshan, and Himalayan movements. The tectonic evo- lution of the paleo-uplift can be divided into the six stages of embryonic formation, development, intense uplifting and erosion, stable burial, western Sichuan foreland development, and finalization, which is mainly influenced by the basement and the lay- ered detachment system.

关 键 词：乐山-龙女寺古隆起 地震解释 滑脱层 地质结构 构造演化 四川盆地 

分 类 号：TE111.2[石油与天然气工程—油气勘探]