摘要
为了深入分析鄂尔多斯盆地北部乌审旗古隆起对其周缘奥陶系马家沟组构造—沉积分异特征的影响,基于地震、测井、岩心及野外剖面等地质资料,对马家沟组沉积期内部应力环境进行分析,通过绘制古地貌图确定该盆地内部地表地形变化,明确马家沟组重点层段的岩相古地理,厘清该区内部岩相分异特征。研究结果表明:(1)在区域构造作用力下,乌审旗古隆起在马家沟组沉积期发生间歇活动,使得鄂尔多斯盆地北部马家沟组沉积期古地貌产生明显的隆坳分异;(2)该区马家沟组岩相古地理也具有明显的分异特征,海进期两坳陷(靖西坳陷、米脂坳陷)相互沟通且与广海相连,在深部位发育灰坪微相,在古隆起发育云坪、灰云坪微相;(3)海退期两坳陷受到乌审旗古隆起的阻隔,并且与广海的沟通也受到其他古隆起的阻隔,在两个坳陷分别发育膏盐湖,古隆起发育含膏云坪、云坪微相。结论认为,乌审旗古隆起对“一隆两坳”的岩相古地理格局在整个马家沟期均有控制作用,影响了该区马家沟组的构造—沉积演化及分异。
To figure out what the tectonic-sedimentary differentiation in Wushenqi paleouplift of northern Ordos Basin has affected on the peripheral Ordovician Majiagou Formation,the internal stress during the deposition of this formation was investigated on the basis of seismic,logging and core data and outcrop survey.And then,paleogeomorphological variations within the basin were determined through paleogeomorphological mapping to make clear lithofacies paleogeography of key Majiagou members.Additionally,the internal lithofacies differentiation was clarified as well.Results show that(i)the paleouplift was active intermittently under the regional tectonism during the deposition of Majiagou Formation,creating the obvious uplift-depression differentiation here;(ii)there existed clear differentiation in the paleogeography for this formation.Jingxi depression linked with Mizhi depression and they connected to open sea during the transgression,in which the lime flat microfacies were extended into the deep whereas the dolomitic flat and limy dolomitic flat microfacies into the paleouplift;and(ii)these two depressions were separated by Wushenqi paleouplift during the regression,and their connection to the open sea was also obstructed by other paleouplifts.And gypsum salt lakes were stretched into the depressions,and gypsum-bearing dolomitic flat and dolomitic flat microfacies into Wushenqi paleouplift.It is concluded that Wushenqi paleouplift exerts the effect on the lithofacies paleogeographical framework of one uplift and two depressions throughout the deposition of Majiagou Formation.
作者
张翔
祁壮壮
丁晓琪
高雯璐
袁倩
钟经治
ZHANG Xiang;QI Zhuangzhuang;DING Xiaoqi;GAO Wenlu;YUAN Qian;ZHONG Jingzhi(College of Energy,Chengdu University of Technology,Chengdu,Sichuan 610059,China;Baikouquan Oil Production Plant,PetroChina Xinjiang Oilfield Company,Karamay,Xinjiang 834000,China;Exploration and Development Research Institute,PetroChina Xinjiang Oilfield Company,Karamay,Xinjiang 834000,China;Exploration and Development Research Institute,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610041,China)
出处
《天然气勘探与开发》
2025年第1期1-10,共10页
Natural Gas Exploration and Development
基金
国家科技重大专项(2017ZX05005-001-010)。
关键词
鄂尔多斯盆地北部
乌审旗古隆起
奥陶系马家沟组
构造—沉积分异
岩相古地理
Northern Ordos Basin
Wushenqi paleouplift
Ordovician Majiagou Formation
Tectonic-sedimentary differentiation
Paleogeography
