同生逆断层正牵引构造对高频层序地层结构及沉积充填的控制作用  

The Controlling Effect on High Frequency Sequence Stratigraphic Architecture and Depositional Filling by Normal Drag Structure, Caused by Contemporaneous Reverse Fault

作　　者：印森林[1,2] 吴胜和[1,2] 李俊飞[1,2] 冯文杰[1,2] 

机构地区：[1]中国石油大学油气资源与探测国家重点实验室,北京102249 [2]中国石油大学地球科学学院,北京102249

出　　处：《地质论评》2014年第2期310-320,共11页Geological Review

基　　金：国家自然科学基金资助项目(批准号41372116)资助的成果

摘　　要：本文拟探讨同生逆断层产生的正牵引构造对高频层序结构及沉积充填的控制作用。利用同生逆断层产生的次级构造要素正牵引构造这个视角来揭示构造与沉积的耦合关系具有其独特性与新颖性。在研究区岩芯、测井及地震资料分析的基础上,结合地质分析、构造平衡剖面技术及井震联合等方法对研究区同生逆断层断层要素进行分析,进而提出正牵引构造的特点以及其对高频层序结构和砂体展布的控制作用机制。研究表明:①正牵引构造的发育具有3个特点,即上盘形成局部隆起向上牵引弯曲的背斜;因应力反转形成沿背斜核部非对称分布的正断层束;其发育部位砂体发育程度低。同时,②同生逆断层正牵引构造对高频层序地层结构控制明显,其下盘地层厚度不仅较上盘明显增厚,且上盘地层因强烈的上拱隆升作用容易遭受剥蚀,从而导致平面上自下而上地层遭受削蚀范围逐渐增大的差异削蚀样式;同时,剖面上垂直断裂走向地层呈"厚—薄—厚"的展布样式。地层削蚀形成的局部不整合界面为层序地层研究的关键界面,其可为等时地层格架的建立提供依据。③正牵引构造引起的差异隆起的沉积底形控制了古水系的流动方向,因而决定了砂体的分散和充填样式。垂直同生逆断层走向方向,隆起背斜部位的砂体发育程度低,以砂泥交互和厚层泥岩夹薄层砂等非主力储层为主;与之相反,正牵引构造发育部位的背斜两翼砂体以厚层连片状主力储层占绝对优势。This paper deal with the control effect of normal drag structure reverse fault on high frequency sequence strata structure and its depositional fillings generated by contemporaneous . It is unique and novel to use secondary structural elements, namely, normal drag structure generated by contemporaneous reverse fault to reveal the coupling relationship between structure and deposition. Based on analysis of core, logging and seismic data, the fault elements of contemporaneous reverse fault in the study area are analyzed through geological analysis, structure balanced section technology and well-to-seismic calibration, etc. Then the characteristics of normal drag structure and its control mechanism on high frequency sequence structure and distribution of sand body are put forward. The results show that normal drag structure has three characteristics, including the formation of curved anticlines in local uplift of hanging wall, approximately nonsymmetrieal normal faults beams caused by stress inversion along the core of anticline and low level development of sand body. High frequency sequence structure is obviously controlled by normal drag structure resulted from contemporaneous reverse fault. The footwall strata thickness is much thicker than that of the upper plate and hanging wall is subjected to erosion due to the strong uplift effect. As a result, the bottom--up formation gradually increases its erosional scale, leading to differential erosion; and ＂thick--thin-- thick＂ distribution pattern of the formation forms vertically to the fracture direction. At the same time, the local unconformity interface formed by formation erosion is the key boundary for sequence stratigraphy study, which also providing a basis for establishment of the isoehronous stratigraphic framework~ Differential uplift depositional bed form formed by normal drag structure controls the direction of ancient flow system, so it determines the dispersion of sand body and filling pattern. The development of sand body is low in uplift anticline

关 键 词：同生逆断层 正牵引构造 高频层序结构 沉积充填 准噶尔盆地西北缘 

分 类 号：P548[天文地球—构造地质学] P618.13[天文地球—地质学]