中非Doseo盆地构造特征及成因演化机制  

Structural characteristic and formation evolution mechanism of Doseo Basin in Central Africa

作　　者：黄迟君 胡望水[1,2] 李希元 孔令武 HUANG Chijun;HU Wangshui;LI Xiyuan;KONG Lingwu(School of the Earth Sciences,Yangtze University,Wuhan,Hubei 430100,China;MOE Key Laboratory of Exploration Technologies for Oil and Gas Resources,Yangtze University,Wuhan,Hubei 430100,China;International Company Limited,CNOOC,Beijing 100010,China)

机构地区：[1]长江大学地球科学学院,湖北武汉430100 [2]长江大学油气资源与勘探技术教育部重点实验室,湖北武汉430100 [3]中国海洋石油国际有限公司,北京100010

出　　处：《东北石油大学学报》2021年第4期35-45,I0003,共12页Journal of Northeast Petroleum University

基　　金：国家科技重大专项(2017ZX05032-002-005)。

摘　　要：利用测井和地震资料,结合地质构造背景,选取中非Doseo盆地典型剖面进行构造解释,采用平衡剖面技术恢复盆地的构造演化过程,基于地幔对流作用探讨盆地的成因演化机制。结果表明:受Doseo-Khartoum转换断裂系作用影响,平面上,Doseo盆地为伴生次级断裂与主干断裂斜交的断裂组合形式;剖面上,盆地断裂倾角表现为高角度近直立状,结构为复式半地堑或地堑形式;盆地经历早白垩世、晚白垩世及古近纪三期不同强度的叠加型转换裂陷—转换反转构造,发育转换型地堑、转换型多米诺、斜向滑动断层、反转背斜和掀斜断块5种构造类型,其中转换型地堑为主要构造类型。Doseo盆地经历早白垩世强转换裂陷期、早白垩世末期转换反转期、晚白垩世弱转换裂陷期、晚白垩世末期转换反转期、古近纪转换拗陷期、古近纪末期转换反转期,以及新近纪—第四纪转换裂陷期7个演化期次,其中早白垩世转换裂陷期转换作用最强烈,形成大量转换型地堑构造。地幔对流作用控制中非裂谷系转换型盆地的形成。Doseo盆地三期叠加的转换裂陷—转换反转构造为油气形成提供良好圈闭,是油气勘探有利区带。With the help of logging and seismic data,moreover selecting the typical sections,combined with tectonic environment,the tectonic evolution process of Doseo Basin is inversed by using the balanced cross-section technique,discussion of the formation evolution mechanism in basins based on the theory of mantle convection.The results show that Doseo Basin is affected by the Doseo-Khartoum transformation fault systems.On the plane,the fault combination is the oblique combination of associated secondary faults and the main fault;on the profile,the dip angle of faults in the basin is high angle and nearly vertical,and the structural type is compound half graben or graben.According to the three stages of superimposed transform rift inversion structure with different strength in the basin on Early Cretaceous,Late Cretaceous and Paleogene,there are five structural styles in Doseo Basin including transformational graben,transformational dominoes,inverted anticlines,tilting blocks and oblique slip faults,and the transform graben is the main structural style.Doseo Basin has experienced seven evolution stages,respectively,Early Cretaceous strong transition rifting stage,Late Cretaceous transition reversal stage,Late Cretaceous weak transition rifting stage,Late Cretaceous transition reversal stage,Late Paleogene transition depression stage,Late Paleogene transition reversal stage and Neogene to Quaternary transition rifting stage.In the Early Cretaceous transition rifting stage,the transition was the most intense and formed a large number of transition graben structures.Mantle convection controls the formation of transitional basins of rift systems in Central Africa rift systems,and explains the dynamic mechanism of inversion structures.Doseo Basin has formed a favorable circle of oil and gas exploration with great exploration potential accumulate because of transition rifts and transition inversion structures of the superimposed three-stages.

关 键 词：转换盆地 构造演化 平衡剖面技术 地幔对流 反转构造 Doseo盆地 中非地区 

分 类 号：TE121.2[石油与天然气工程—油气勘探]