裂陷盆地伸展方位与构造作用及对构造样式的控制——以苏北盆地高邮凹陷南部断阶带为例

发布时间：2018-03-27 18:00

本文选题：伸展　切入点：走滑　出处：《石油与天然气地质》2017年01期

【摘要】：南部断阶带为苏北盆地高邮凹陷边界构造带,由吴堡断阶带和真武断阶带两个部分组成,具有复杂的构造作用过程和构造样式。在南部断阶带几何学特征研究基础上,以应力-应变分析理论为指导,利用平衡剖面法反演所得的伸展率进行横向对比,明确高邮凹陷各时期的优势伸展方位,从而分析南部断阶带的构造作用及其对构造样式的控制。结果表明,高邮凹陷优势伸展方位经历了NW向(K_2t~2—E_2d),NS向(E_2s)和NW向(Ny—Qd)的变化过程,首次从定量角度深入认识了高邮凹陷晚白垩世以来的构造应力场方向。由于不同时期优势伸展方位与断阶带呈不同角度斜交,吴堡断阶带经历了纯伸展、右行走滑-伸展与纯伸展3期构造作用,形成了平面斜交式和剖面马尾状的简单断层组合样式;真武断阶带经历了左行走滑-伸展、右行走滑-伸展和左行走滑-伸展3期构造作用,形成了平面网格式与剖面复式马尾状的复杂断层组合样式。伸展速率与走滑速率研究表明,断阶带伸展与走滑作用主要发生在阜宁组、戴南组和三垛组,多期次的走滑-伸展作用是南部断阶带构造样式的主要控制因素。
[Abstract]:The southern fault terrace is a boundary structural belt of Gaoyou depression in Subei basin, which is composed of two parts: Wubao fault terrace and Zhenwu fault terrace. It has complicated tectonic process and structural style. On the basis of the study of the geometric characteristics of the southern fault terrace zone, the southern fault terrace is composed of two parts: Wubao fault terrace and Zhenwu fault terrace. Under the guidance of the stress-strain analysis theory, the extension ratio obtained by the equilibrium section method is compared horizontally, and the dominant extension azimuth of each period in Gaoyou sag is determined. The result shows that the dominant extension orientation of Gaoyou sag has experienced the change of NW direction, 2t ~ 2-E _ 2d ~ +, NS _ S _ 2s) and NW direction _ Ny-Qd _ d _ (), the results show that the tectonic action of the southern fault terrace zone and its control on the structural style are analyzed. The direction of tectonic stress field since the late Cretaceous in Gaoyou sag was understood for the first time from a quantitative point of view. The Wubao fault zone experienced pure extension due to the different angles between the dominant extensional azimuth and the fault terrace in different periods. Right-strike-extensional and pure extensional tectonics formed a simple fault combination style of plane oblique type and section horsetail shape, while the Zhenwu fault terrace experienced left strike-slip extension, The structures of right strike-extensional and left-strike-extensional structures formed complex fault combination styles of plane grid type and section compound horsetail type. The study of extension rate and strike-slip rate shows that, The extension and strike-slip of the fault terrace mainly occurred in Funing formation, Dainan formation and Sanpong formation. The multi-stage strike-slip extension is the main controlling factor of the structural style of the southern fault terrace.
【作者单位】：中国石油勘探开发研究院;中国石油大学(华东)地球科学与技术学院;中国石油东方地球物理公司新兴物探开发处;
【基金】：国家自然科学基金项目(41472176)
【分类号】：P618.13

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