鄂尔多斯盆地东缘晋西挠褶带中段构造特征及演化  

Tectonic characteristics and evolution of the middle segment of the Jinxi flexure fold belt in the eastern margin of the Ordos Basin

作　　者：石婧 何登发[1] Shi Jing He Dengfa(School of Energy Resources,China University of Geosciences(Beijing),Beijing 100083)

机构地区：[1]中国地质大学(北京)能源学院,北京100083

出　　处：《地质科学》2024年第3期723-731,共9页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：中国石油长庆油田公司科技攻关项目“鄂尔多斯盆地中元古界-奥陶系构造沉积演化、成源机制与勘探新领域”(编号: ZDZX2021-01);国家自然科学基金企业创新发展联合基金项目“海相深层油气富集机理与关键工程技术基础研究”(编 号:U19B6003)资助。

摘　　要：现今晋西挠褶带作为鄂尔多斯盆地的残余东部边界存在,近年来在上古生界石炭系—二叠系中发现有煤层气、致密气等丰富的油气资源,是一个重要的勘探领域。本文基于野外露头、钻井、地震资料等,明确其地层发育分布特征,结合浅表露头构建区域地质剖面,并利用2D-move软件对其进行反演分析与正演模拟,同时对其构造变形进行定量分析,研究表明:1)鄂尔多斯东缘晋西挠褶带中段主要在燕山期受东西向的挤压应力以及深部构造楔活动影响发生陆内构造变形,并遭受强烈的差异风化剥蚀作用,形成现今构造格局。2)研究区剖面现今长度约为114.96 km,以寒武系为标志层,燕山期地层缩短约4.06 km,地层抬升约6.12 km,地层缩短率为3.41%。3)晋西挠褶带中段形成原因为受到多方向的挤压构造应力作用,主要动力来源为古太平洋板块的西向低角度俯冲挤压。晋西挠褶带中段是重要构造单元,具深刻的动力来源。本文可为之后鄂尔多斯盆地东缘的陆内构造变形、演化特征研究以及油气勘探方向提供参考依据。Nowadays,the Jinxi flexure fold belt exists as the remnant eastern boundary of the Ordos Basin.In recent years,rich oil and gas resources such as coalbed methane and tight gas have been found in the Upper Paleozoic Carboniferous-Permian,which is an important exploration field.Based on the field outcrops,drilling,seismic data,etc.,the development and distribution characteristics of the strata are clarified,the regional geological profile is constructed in combination with the shallow outcrops,and the inversion analysis and forward simulation are carried out by 2D-move software,and the tectonic deformation is quantitatively analyzed.The results show that:1)the middle segment of the Jinxi flexure fold belt in the eastern margin of Ordos is mainly affected by the east-west compressive stress and deep tectonic wedge activity in the Yanshan Period,and suffers from strong differential weathering and denudation.The current tectonic pattern has been formed.2)The current length of the section in the study area is about 114.96 km,and the Yanshan Period strata are shortened by about 4.06 km;the strata are uplifted by about 6.12 km;and the strata shortening rate is 3.41%.3)The formation of the middle segment of the Jinxi flexure fold belt is due to the multi-directional compressive tectonic stress,and the main dynamic source is the westward low-angle subduction and extrusion of the Paleo-Pacific Plate.The middle segment of the flexure fold belt is an important tectonic unit with a profound dynamic source,and this paper can provide a reference for the study of the onshore tectonic deformation and evolution characteristics and the direction of oil and gas exploration in the eastern margin of the Ordos Basin.

关 键 词：华北克拉通 鄂尔多斯盆地 晋西挠褶带 构造特征 构造演化 

分 类 号：P542[天文地球—构造地质学]