鄂尔多斯盆地早古生代构造分异类型与分布特征  

Tectonic differentiation and distribution of Early Paleozoic Ordos basin

作　　者：何登发[1] 牛小兵[2] 郑娜 刘新社[2] 毛丹凤 包洪平[2] 邹松 魏柳斌[2] 成昌宇 HE Dengfa;NIU Xiaobing;ZHENG Na;LIU Xinshe;MAO Danfeng;BAO Hongping;ZOU Song;WEI Liubin;CHENG Changyu(School of Energy Resources,China University of Geosciences(Beijing),Beijing 100083,China;PetroChina Chanqing Oilfield Company,Xi’an,Shaanxi 710018,China)

机构地区：[1]中国地质大学(北京)能源学院,北京100083 [2]中国石油长庆油田分公司,陕西西安710018

出　　处：《地质学报》2024年第12期3601-3618,共18页Acta Geologica Sinica

基　　金：国家自然科学基金重点项目“上扬子克拉通盆地深层新元古代裂谷体系的结构、成因及其控油气作用”(编号42330810);中国石油长庆油田分公司重大科技攻关项目“鄂尔多斯盆地及周缘中元古界-奥陶系构造-沉积环境、成源机制与勘探新领域”(编号ZDZX2021-01)联合资助的成果。

摘　　要：构造分异是地球表面的一种常见现象,它导致均一地表出现各种不同的地形、地貌与构造起伏,是地球内动力(构造应力、热、重力等)、外动力(气候、全球海平面、水体等引起的风化、剥蚀、搬运、沉积等)甚至地外事件(星际空间等天文因素)等共同作用的结果。克拉通是岩石圈的基本构造单元,具有厚度大、长期稳定的特点;但克拉通的内部与边缘常常出现多类构造分异作用,剖析这种构造分异对于了解克拉通的构造活动性以及克拉通盆地的成因、演化与矿产赋存具有重要意义。本文聚焦于鄂尔多斯盆地早古生代的构造分异作用,在大量高精度反射地震、钻井等资料分析的基础上,识别了构造分异的类型,厘定了构造分异的分布特点。研究表明,鄂尔多斯盆地早古生代构造分异体现在其“面”或“体”的变化上,“面”的变化如形成地层不整合面(超覆、削截、下切等)、断层面(正断层、逆断层、走滑断层等)等,“体”的变化如出现前积体、生物礁(生物滩、生物丘)、底辟(盐或岩浆)等;这些构造分异类型在空间上组合可以形成断阶带、裂陷槽、叠加隆起等多种样式,随时间演化构造分异可以在所形成的被动大陆边缘、前陆、叠合坳陷等不同类型盆地中发生继承、新生或改造,出现更为复杂的叠加结构样式;该盆地早古生代的构造分异作用形成了寒武系底界、寒武系顶界,奥陶系顶界等三大不整合面,伊盟、乌审旗、庆阳、吕梁等四个古隆起,以及富平-洛川、神木-清水河、定边等三个裂陷带,隆起带与裂陷带分布于不同时期原型盆地的不同构造位置,相间发育。鄂尔多斯盆地早古生代的构造分异对下古生界的源、储发育及其组合、油气生-运-聚作用与油气藏分布等有重要影响,目前在奥陶系顶界不整合面风化壳已发现靖边万亿方大气田,在盆地中东部的马家�Tectonic differentiation is a common phenomenon on the Earths surface,shaping its diverse geographic,geomorphic,and tectonic relief.This differentiation arises from the complex interaction of internal geodynamic forces,such as tectonic stress,thermal gradients,and gravitational forces;external geodynamic forces,such as weathering,erosion,transportation,and deposition,which are driven by climatic changes,eustatic sea-level fluctuations,and water activity;and extraterrestrial factors,like interplanetary astronomical influences.Cratons,the basic units of the lithosphere,are characterized by their huge thickness and long periods of stability.However,variations in tectonic differentiation in the interior and along the periphery of the cratons are often observed.Understanding these variations is crucial for comprehending cratonic mobility,genetic mechanisms,evolution,and mineral deposit occurrence,particularly within cratonic basins.This paper focuses on the tectonic differentiation of the Early Paleozoic Ordos basin,recognizing its types and delineating its distribution using extensive borehole data and highresolution reflection seismic profiles.The study reveals that tectonic differentiation in the Early Paleozoic Ordos basin manifests in two primary ways:surface changes and body changes.Surface changes include unconformities(onlapping,truncation,and downward cutting)and various fault surfaces(normal,reverse,and strike-slip).Body changes are represented by progradation bodies,bioherms(reefs or biomass dunes),and diapiric structures(upward-moving intrusions of salt or magma).These tectonic differentiations combine to form distinct features such as normal fault terraces,rifted troughs,and superimposed uplifts.Their temporal evolution is characterized by complex superimposed structural styles,including successive,newly formed,and modified structures,occurring in passive margins,foreland basins,and superimposed depressions.The Early Paleozoic Ordos basin exhibits distinctive tectonic differentiation marked by three major

关 键 词：构造分异 早古生代 内动力作用 外动力作用 大油气田 鄂尔多斯盆地 

分 类 号：P618.13[天文地球—矿床学]