New fossiliferous sites from the mid-Cretaceous Tendrara dome (High Plateaus, Morocco): biostratigraphical, paleoenvironmental and paleogeographical implications

• Published in: Cretaceous research Vol. 161; p. 105908
• Main Authors: Haddoumi, Hamid, Guinot, Guillaume, Chennouf, Rachid, Amakrane, Jemaa, Vianey-Liaud, Monique, Rossi, Abdelhamid, Mamoun, Sidi Mohamed, Tabuce, Rodolphe, Charrière, André
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2024; Elsevier
• Subjects: Charophytes; Dinosaur eggshells; Elasmobranchs; Life Sciences; Mid-Cretaceous; Morocco; Ostracods; Mid-Cretaceous; Charophytes; Dinosaur eggshells; Morocco; Ostracods; Elasmobranchs
• ISSN: 0195-6671; 1095-998X
• DOI: 10.1016/j.cretres.2024.105908

Sedimentological and stratigraphical studies in the Cretaceous series of the Tendrara dome led to the discovery of fossiliferous levels in the pre-Cenomanian and Cenomanian deposits, providing significant biostratigraphic, paleoenvironmental, and paleogeographic results. In the SW part of the Tendrara dome, the predominantly terrigenous deposits at the base of the pre-Cenomanian (Dekkar 1 Formation) yielded dinosaur eggshell fragments and charophytes, in particular Clavatoraceans, pointing to the Barremian-Aptian. Above this unit, two beds with fish remains were discovered in the Dekkar 2 Formation and at the base of the Dekkar 3 Formation, respectively. To the NE of the Tendrara dome, a fossiliferous site with diversified benthic fauna and abundant fish remains was discovered in a thin marly unit unconformably overlying the Middle Jurassic basement. Elasmobranch micro-remains indicate a Cenomanian age for this unit. The SW-NE correlations indicate a marked thickness reduction and lateral facies variations, implying a strong asymmetry in the Cretaceous paleogeography of the dome. The first continental and lagoonal basins of the Barremian-Aptian and Albian?-Cenomanian are located in the southern part of the Tendrara dome. The Cenomanian transgression, initiated from the south, gradually covered the dome, depositing reduced coastal plain elasmobranch-rich facies in its northern part. The Tendrara dome constituted a paleogeographic barrier, limiting the first transgressions of the Cenomanian sea. This paleostructure is part of an emerged area (Idrissides High) located between the Tethyan Ocean and the Saharan epicontinental sea. •Clavatoracean charophytes allow to date the Barremian-Aptian.•Elasmobranch associations indicate a Cenomanian age.•Lagoonal-marine precursor episodes of the Cenomanian-Turonian transgression.•Strongly differentiated pre-Cenomanian and Cenomanian paleogeography.•The Tendrara dome constituted a Cenomanian paleogeographic coastal edge.