Messinian to Piacenzian deposits, erosion, and subsequent marine bioevents in the Dahra Massif (Lower Chelif Basin, Algeria)

• Published in: Arabian journal of geosciences Vol. 14; no. 8
• Main Authors: Osman, Mohamed Kamel, Bessedik, Mostefa, Belkebir, Lahcene, Mansouri, Mohamed EI Habib, Atik, Asma, Belkhir, Ayoub, Rubino, Jean-Loup, Satour, Linda, Belhadji, Ahmed
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.04.2021; Springer Nature B.V
• Subjects: Carbonation; Correlation; Deformation; Deposits; Earth and Environmental Science; Earth science; Earth Sciences; Geology; Gravity; Gypsum; Lake deposits; Marine invertebrates; Massifs; Messinian; Original Paper; Plate tectonics; Pliocene; Tectonics; Valleys; Work platforms; Gypsum; Messinian; Pliocene bioevents; Lago Mare; Correlations; Biostratigraphy
• ISSN: 1866-7511; 1866-7538
• DOI: 10.1007/s12517-021-06481-0

Six geological studied sections from the Ouled Maallah region (Dahra) allow the identification of lacustrine deposits, sandwiched between Messinian gypsum and Mio-Pliocene blue marls. The gypsum followed by white micritic limestones deposits is correlated with the “Terminal Carbonated Complex” subsequent to the coral platforms (Oran, Melilla, Sorbas). Correlated to the Lago Mare 1 episode, which is slightly older than 5.60 Ma, the lacustrine deposits tend to cover a large extension area, both on the southern margin of the Dahra and on the Beni Chougrane northern slopes. Subsequently, the early Messinian-Zanclean deposits fossilize the Messinian Erosional Surface and indicate the post-Messinian Crisis marine reflooding. They are characterized by two microfossiliferous successions: (i) the presence of Sphaeroidinellopsis subdehiscens , Globorotalia margaritae (foraminifers), Ceratolithus acutus , Reticulofenestra zancleana (calcareous nannofossils) indicating the latest Messinian to earliest Zanclean, followed by an association with (ii) G. puncticulata , G. bononiensis , G. aff. crassaformis and Helicosphaera sellii , Discoaster asymmetricus , and D. tamalis , indicating a late Zanclean age up to an early Piacenzian one. The regional correlations reveal large subsiding sedimentary depocentres built along the Chelif Valley. Likewise, the Mio-Pliocene sedimentation seals folded tectonics active during the latest Messinian, individualized by the tilted gypsum and Lago Mare deposits of Ouled Maallah. This deformation has resulted from gravity tectonics responsible for the “olistolite” made or reworked materials within the geological series located at the Chelif Valley and the Beni Chougrane Mounts. This testifies to a large-scale, compressive deformation that would correspond to a restructuring of paleogeographic spaces associated with the Tellian Massif uplifts.