Tectonic features,genetic mechanisms and basin evolution of the eastern Doseo Basin,Chad  

作　　者：GAO Huahua DU Yebo WANG Lin GAO Simin HU Jie BAI Jianfeng MA Hong WANG Yuhua ZHANG Xinshun LIU Hao 

机构地区：[1]China National Oil and Gas Exploration and Development Corporation,Beijing 100034,China [2]Research Institute of Petroleum Exploration and Development,PetroChina,Beijing 100083,China [3]Exploration and Development Research Institute of PetroChina Yumen Oilfield Company,Jiuquan 735019,China [4]Research Institute of Bureau of Geophysical Prospecting Inc.,CNPC,Zhuozhou 072751,China

出　　处：《Petroleum Exploration and Development》2023年第5期1151-1166,共16页石油勘探与开发（英文版）

基　　金：Supported by the PetroChina Science and Technology Project(2021DJ3103)。

摘　　要：The features of the unconformity,fault and tectonic inversion in the eastern Doseo Basin,Chad,were analyzed,and the genetic mechanisms and basin evolution were discussed using seismic and drilling data.The following results are obtained.First,four stratigraphic unconformities,i.e.basement(Tg),Mangara Group(T10),lower Upper Cretaceous(T5)and Cretaceous(T4),four faulting stages,i.e.Barremian extensional faults,Aptian–Coniacian strike-slip faults,Campanian strike-slip faults,and Eocene strike-slip faults,and two tectonic inversions,i.e.Santonian and end of Cretaceous,were developed in the Doseo Basin.Second,the Doseo Basin was an early failed intracontinental passive rift basin transformed by the strike-slip movement and tectonic inversion.The initial rifting between the African and South American plates induced the nearly N-S stretching of the Doseo Basin,giving rise to the formation of the embryonic Doseo rift basin.The nearly E-W strike-slip movement of Borogop(F1)in the western section of the Central African Shear Zone resulted in the gradual cease of the near north-south rifting and long-term strike-slip transformation,forming a dextral transtension fault system with inherited activity but gradually weakened in intensity(interrupted by two tectonic inversions).This fault system was composed of the main shear(F1),R-type shear(F2-F3)and P-type shear(F4-F5)faults,with the strike-slip associated faults as branches.The strike-slip movements of F1 in Cretaceous and Eocene were controlled by the dextral shear opening of the equatorial south Atlantic and rapid expanding of the Indian Ocean,respectively.The combined function of the strike-slip movement of F1 and the convergence between Africa and Eurasia made the Doseo Basin underwent the Santonian dextral transpressional inversion characterized by intensive folding deformation leading to the echelon NE-SW and NNE-SSW nose-shaped uplifts and unconformity(T5)on high parts of the uplifts.The convergence between Africa and Eurasia caused the intensive tectonic inversion

关 键 词：Doseo Basin CRETACEOUS UNCONFORMITY strike-slip fault tectonic inversion genetic mechanism basin evolution 

分 类 号：P54[天文地球—构造地质学]