Basement structure, seismostratigraphy, and structural inheritance during the rifting of the Ifni/Tan-Tan margin (southwestern Morocco)

Seismic reflection profiles from the Ifni/Tan-Tan Atlantic margin of southern Morocco, interpreted in the light of well data and field geology from the Western Anti-Atlas, allowed us to establish the seismostratigraphic framework of the syn-rift series and to reveal (i) a compressional structural style in the pre-Triassic basement similar to that established in the adjacent outcropping onshore basement but with an opposed western vergence, (ii) the importance of inherited anterior structures in the formation of Triassic-Liassic rift structures and (iii) an east-west propagation of these rift structures.Original Abstract: L'analyse des profils sismiques de reflexion de la marge atlantique sud-marocaine au large d'Ifni/Tan-Tan, a la lumiere des donnees de forages et des donnees de surface anterieures, acquises au niveau de l'Anti-Atlas occidental, permet de definir le cadre sismo-stratigraphique de la serie synrift de cette zone et d'y reveler (i) la presence, dans le socle ante-triasique, d'un style structural compressif similaire a celui identifie a terre mais a vergence opposee, (ii) la reactivation des structures compressives hercyniennes lors du rifting atlantique, et (iii) la propagation du rifting de l'est vers l'ouest.