北非地区构造演化与含油气盆地形成OACSTPCD

North Africa,located on the northern margin of the Gondwana continent in Paleozoic era,is one of the important oil and gas enrichment areas worldwide,experiencing two rift-sag-foreland basin evolution cycles,namely the Paleozoic Gondwana and the Mesozoic Cenozoic Tethys.Based on a compre-hensive analysis of publicly available geological data and oil and gas exploration data,this article identi-fied three types of petroliferous basins in the North African region:cratonic superimposed sags,rifts,and passive margin related basins;summarized two basin evolution cycles:Gondwana and Tethyan basin-form-ing cycle;clarified the controlling role of tectonic evolution on basin types,basin structures,and the development of source,reservoir,and cap rocks.Under the influence of the global plate tectonic evolu-tion,different regions in North Africa have gone through five stages of tectonic evolution:(1)late Proter-ozoic-early Cambrian basement assembly and rift stage;(2)Cambrian-Early Carboniferous intra-cratonic sag stage;(3)Late Carboniferous-Early Permian Hercynian orogenic stage;(4)Late Permian-Early Cretaceous rift stage;and(5)Late Cretaceous-Present Alpine orogenic stage.Marked by the Hercynian orogeny,the basin features cycles that consist of the Paleozoic Gondwana Cycle and the Mesozoic-Cenozoic Tethyan Cycle.The evolution of the basins in western North Africa are dominated both by the Gondwana and Tethyan cycles,forming superimposed sag basins,while the evolution of the eastern basins are domi-nated by the Mesozoic and Cenozoic Tethyan cycle,forming the Mesozoic and Cenozoic rift basins and pas-sive continental margin basins.Controlled by the development differences of basins,the source rocks of the western superimposed sag basins are developed mainly in Silurian and Devonian,with including the Paleo-zoic and Triassic reservoirs.The regional cap rocks are Silurian shale and Upper Triassic-Lower Jurassic evaporate.In comparison the source rocks of the eastern rift basins developed in Cretaceous,Paleogene,and Neogene,with pre-rift Paleozoic and syn-rift Mesozoic and Cenozoic reservoirs.The regional caprocks include the Late Mesozoic and Cenozoic evaporites rocks deposited in the rifting stages.Overall,the dif-ferential tectonic evolution in the North African controls the formation mechanism of petroliferous basins and the distribution of source,reservoir,and cap rocks.