鄂尔多斯盆地中央古隆起的地质结构与成因机制  

Geologic structure and genetic mechanism for the central uplift in the Ordos Basin

作　　者：何登发[1] 包洪平[2] 孙方源[1] 张才利[2] 开百泽 许艳华 成祥 翟咏荷 He Dengfa;Bao Hongping;Sun Fangyuan;Zhang Caili;Kai Baize;Xu Yanhua;Cheng Xiang;Zhai Yonghe(China University of Geosciences Beijing,Beijing 100083;Research Institute of Exploration and Development,PetroChina Changqing Oilfield Company,Xi'an 710018)

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勘探开发研究院,西安710018

出　　处：《地质科学》2020年第3期627-656,共30页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：国家油气专项课题“岩性地层油气藏成藏规律、关键技术及目标研究”(编号:2017ZX05001-001);中国石油集团公司重大专项“长庆油田5000万吨持续高效稳产关键技术研究与应用”(编号:2016E-0514)资助。

摘　　要：克拉通盆地内古隆起是了解板内变形机制的重要窗口,也是油气、煤、盐、铀等矿产勘查的主要对象,一直是盆地分析的热点领域。本文以鄂尔多斯盆地中央古隆起为例,利用新的高精度反射地震剖面与深探井资料,解剖古隆起的地质结构,刻画构造演化过程,探讨其形成机制。研究表明,鄂尔多斯盆地古生代隆起带发育在华北克拉通地块中西部,自伊盟—杭锦旗、乌审旗—定边,南延至镇原—正宁一带,呈“工”字形,面积达7.5×10^4 km^2以上;伊盟凸起为基底隆起,镇原隆起为多阶段、间隙性发育的剥蚀与沉积型隆起,定边凸起为沉积型隆起。它是基底分异构造格局与周缘板块构造事件共同控制的产物,为在中元古代裂陷基础上早古生代被动大陆边缘背景下发育演化的古隆起;古生代早期,邻接周缘洋盆表现为台缘隆起;石炭纪晚期—二叠纪早期,因差异升降而具陆缘隆起性质;印支晚期—燕山期以来,隐伏于天环坳陷之下埋藏沉没。鄂尔多斯盆地中央隆起带为多机制复合成因,伊盟凸起为基底强烈伸展、长期剥露剥蚀型隆起;镇原凸起为西缘断阶迁移、南缘前缘隆起叠加的复合隆起;定边凸起为断阶迁移、挤压叠加的继承性隆起。鄂尔多斯盆地中央隆起带对盆地内部的构造—沉积分异施加了重要影响,其两翼斜坡带是油气聚集的有利区带。The paleo-uplift in the intra-cratonic basin is not only the key window to understand the in-plate deformation mechanism,but also the main exploration target of the mineral deposits such as oil and gas,coal,salt,and uranium etc.It is always the hot topic for basin analysis.Taking the central paleo-uplift in the Ordos basin as an example,the paper is to analyze its geologic structure,characterize the process of tectonic evolution,and discuss the formation mechanism by utilizing the newly acquired high-resolution reflection seismic profiles and deep boreholes.It shows that,the uplift zone in Paleozoic is situated on the western North China Craton,which goes from the Yimeng-Hangjinqi High in the north,the Wushenqi-Dingbian High in the middle,and to Zhenyuan-Zhenning High in the south taking a form of“工”character in Chinese words,with an area more than 7.5×10^4 km^2.The Yimeng High is a basement uplift,while the Zhenyuan High is a multi-stage and continual depositional uplift intervening with erosion,and the Dingbian High is a typical depositional uplift.The central uplift zone is resulted from both of the differentiation in the basement framework and the tectonic events of the peripheral plates,characterized by the paleo-high under the tectonic setting of passive margin in Early Paleozoic on the basis of the Middle Proterozoic rifts.In the earlier Paleozoic,it is the uplift along the platform margin adjacent to the oceanic basins.In the Late Carboniferous to the Early Permian,it has a character of uplift circled the continent due to the differential subsidence.It is buried under the Mesozoic Tianhuan depression since the late Indosinian to the Yanshanian Movements.It has thus a composite origin of different mechanisms,with the Yimeng High a basement uplift of extensive extension,long-period exhumation,and denudation,the Zhenyuan High a composite uplift characterized by the normal fault-step migration along its western margin and the superimposition of fore-bulges along its southern margin,while the Dingbian H

关 键 词：克拉通盆地 古隆起 板内变形 构造演化 成因机制 鄂尔多斯盆地 

分 类 号：P542[天文地球—构造地质学]