Reconstruction of Mesozoic paleostress associated with the tectono-sedimentary evolution of the basins bordering the Aouli inlier (Upper Moulouya, Morocco)

Abstract

During the Mesozoic, the basins bordering the Aouli inlier (BBAI) experienced a geodynamic evolution marked by five successive stages: (i) during the Upper Triassic-Middle Liassic (Middle Carixian?), several sedimentary basins occurred with detrital, volcanic, and carbonate filling. Sedimentation and volcanism are controlled by NE-SW to E-W normal faults developed under a NW-SE to NNW-SSE extensional tectonic regime related to the Atlas rifting stage; (ii) during the Middle Liassic (Upper Carixian?-Domerian)-Toarcian, a pure extensive tectonic regime with NE-SW trending σ3 axis is responsible for the appearance NW-SE synsedimentary normal faults. Lateral variations of facies and thicknesses of layers and basin subsidence are controlled by these faults; (iii) during the Aalenian-Bajocian, the tectonic regime is extensive with NNW-SSE σ3 axis responsible for southward deepening of the sedimentary basins bounded by ENE-WSW normal faults. Sedimentary series are represented by bioclastic limestones and a thick succession of marls; (iv) during the Infracenomanian, the tectonic regime becomes transpressive with a sub-horizontal NNW-SSE trending σ1 axis. This is responsible for the development of ENE-WSW reverse faults, NE-SW and NW-SE strike-slip faults, the folding of Jurassic series, and the deposit of ante-Cenomanian continental succession unconformably overlying the underlying series; (v) during the Cenomano-Turonian, the setting up of carbonate platform marks a marine transgression on the entire Upper Moulouya domain. This is related to an extensive tectonic regime with sub-horizontal NW-SE σ3 axis, responsible for the development of NE-SW trending normal faults that control marine transgression and the subsidence of Cretaceous basins.