Mise en évidence d'une série réduite de haut-fond pélagique, de l'Oxfordien au Berriasien, dans les blocs calcaires sud-telliens de l'Ouest algérien : implications paléogéographiques et structurales

The detailed stratigraphic study of some calcareous blocks of Jurassic age, in the Southern part of the Tellian basin (Ouarsenis Mountains) evidences a reduced series (about 30 m thick) throughout the Malm where 8 ammonite zones have been recognized: The top of the series (Upper Tithonian-Berriasian) is dated by Calpionellids. The carbonate deposits characterized a pelagic shoal (=paleohorst of Bou Hadjar-Bechtout immerged from the Callovian), of capital paleogeographical importance, separating a septentrional open-sea realm and a meridional realm (Tellian foreland) greatly subsiding with emersive conditions (Upper Malm). The blocks are interpreted as pop up wedge structures the rise of which is in relation with the compressive Alpine tectonics (especially during the Miocene)