Barremian pyritic ammonites from the western External Rif (northwest Morocco)

Abstract

In the External Rif, northwest Morocco, the Barremian Stage is represented by a thick (200 m) marl and marly limestone series. This series, particularly in the western part of the External Rif, is locally rich in pyritic ammonites. Four Barremian outcrops (Malha, Jebel Meguedrouz, Jebel Bourhzine, and Mrejet), located between Mjara and Mrejet have been studied. Collected ammonites (931 specimens) from the four outcrops allow the identification of 38 species, characterizing the Hauterivian and the lowermost Barremian, at the Mrejet section; the uppermost lower Barremian, at Mrejet and Bourhzine sections, and the upper Barremian, at Mrejet and Malha sections. These species are described and illustrated for the first time from the External Rif. Most of them are reported for the first time from the studied area. They are common to several Lower Cretaceous basins of the southern and northern margins of the Tethys, mainly NE Algeria, SE Spain, SE France, Italy, eastern Serbia, Hungary, Slovakia, and Romania. Stratigraphic and paleogeographic distributions of each species are discussed.