A review of the crustal architecture and related pre-salt oil/gas objectives of the eastern Maghreb Atlas and Tell: Need for deep seismic reflection profiling
Résumé
The Atlas and Tell domains constitute a major segment of the Circum-Mediterranean Alpine fold and thrust belts in the Maghreban part of North Africa. South of the Tell, the Atlas results from a progressive Late Cretaceous to present foreland inversion of former Jurassic to Cretaceous extensional tectonic features inherited from the opening of the Tethys along the northern African margin. In contrast, the Tell is made up of allochthonous Cretaceous to Neogene basinal units detached along a tectonic sole made up of remobilized Triassic salt and tectonic mélanges.
Since the last decade, the major tectonic steps accounting for the development of the eastern Maghreb structures are becoming more precisely constrained by seismic data and associated structural analyses. However their overall configuration at depth, as well as the deep architecture of the underlying basement remain poorly understood because only few wells yet penetrated deeper than the Triassic series in the Atlas and adjacent foreland basin. Therefore, this paper is intended to give an overview on the deep structural features affecting the Pan-African basement in the eastern Maghreb by means of tentative regional cross-sections. Our purpose is to stimulate exploration of deep hydrocarbon plays and give some insights to help both the industry, universities and other public research institutes to undertake jointly a major research program on the deep crustal configuration in the eastern Maghreb with particular focus on the pre-Triassic series beneath the Tellian allochthon in the north, the parautochthonous inverted Atlasic structures in the center, and in the adjacent autochthonous foreland domain extending southeastward in the offshore.