7 research outputs found
Lithostratigraphic, paleoenvironmental and sequential evolution of the Cenomanian-Lower Turonian in the Guir area (western Algeria)
La lithostratigraphie, les palĂ©oenvironnements et la stratigraphie sĂ©quentielle des terrains crĂ©tacĂ©s affleurant au pied mĂ©ridional de l'Atlas saharien (Sud-Ouest de l'AlgĂ©rie), sont discutĂ©s dans le prĂ©sent article. Les Ă©tudes s'appuient sur l'analyse de quinze coupes rĂ©parties le long des limites mĂ©ridionale et septentrionale du bassin du Guir, entre Ben-Zireg, Ă l'Est et l'axe Meridja-Boukais Ă l'Ouest. Dans cette rĂ©gion, trois formations ont Ă©tĂ© identifiĂ©es et interprĂ©tĂ©es sur le plan environnemental et sĂ©quentiel : 1- La Formation des "GrĂšs rouges", attribuĂ©e au CĂ©nomanien infĂ©rieur, est dominĂ©e par des dĂ©pĂŽts grĂ©seux fins, fluviatiles ou littoraux ; 2- La Formation des "Marnes Ă gypse infĂ©rieures", rapportĂ©e au CĂ©nomanien infĂ©rieur-moyen, est caractĂ©risĂ©e par des assises Ă caractĂšres littoraux, soumises Ă l'influence des tempĂȘtes, notamment vers la base ; 3- La Formation des "Calcaires de Sidi Mohamed Ben Bouziane", d'Ăąge CĂ©nomanien supĂ©rieur-Turonien infĂ©rieur, correspond Ă une sĂ©dimentation carbonatĂ©e franchement marine de plate-forme peu profonde trĂšs gĂ©nĂ©ralisĂ©e. Les dĂ©pĂŽts de ces entitĂ©s lithostratigraphiques s'agencent en mĂ©gasĂ©quence d'ouverture, composĂ©e de mĂ©so-sĂ©quences "transgression-rĂ©gression". L'ouverture des milieux de dĂ©pĂŽts en direction du Nord est confirmĂ©e par l'organisation des unitĂ©s lithostratigraphiques et par l'affinitĂ© palĂ©obiogĂ©ographique nettement tĂ©thysienne de l'Ă©chinofaune, des bivalves et en particulier de l'ammonite Neolobites vibrayeanus.The lithostratigraphy, paleoenvironment and sequence stratigraphy of the Cretaceous succession outcropping at the southern foot of the Saharan Atlas (south-western Algeria) are discussed in this work. Our current study focuses on the analysis of fifteen sections distributed along to the northern and southern limits of the Guir Basin, between the Ben-Zireg to the East and the Meridja-Boukais axis to the West. In this area, three lithostratigraphic formations were identified and interpreted from an environmental and a sequential points of view: 1 - The lower "GrĂšs rouges" Formation attributed to the Lower Cenomanian, is dominated by fluvial or coastal detrital deposits; 2 - The middle "Marnes Ă gypse infĂ©rieures" Formation assigned to the Lower-Middle Cenomanian is characterized by littoral setting with some storm influences, especially towards the base; 3 - The upper "Calcaires de Sidi Mohamed Ben Bouziane" Formation of upper Cenomanian-early Turonian in age, is represents a laterally extensive, shallow carbonate platform environment. The three formations constitute an overall transgressive megasequence built of a number of transgressive-regressive minor sequences. The opening of the deposits towards the North is confirmed by the organization of the lithostratigraphic units and by the Tethyan paleobiogeographic affinity of the echinoids and bivalves, and especially the occurrence of Neolobites vibrayeanus ammonite
New stratigraphic data from the Cretaceous Basin of Guir (Bechar, South-Western Algeria)
Benyoucef Madani, Malti Fatima Zohra, Bensalah Mustapha, Bendella Mohamed. New stratigraphic data from the Cretaceous Basin of Guir (Bechar, South-Western Algeria). In: Documents des Laboratoires de Géologie, Lyon, n°164, 2008. Mid-Mesozoic life and environments. Cognac (France), June 24th-28th 2008. pp. 19-22
Callovo-Oxfordian ichnofacies of Takhmaret Area (Saida Mounts, Western-North Algeria)
Bendella Mohamed, Benhamou Miloud, Benyoucef Madani, Malti Fatima Zohra, El Habib Hadj. Callovo-Oxfordian ichnofacies of Takhmaret Area (Saida Mounts, Western-North Algeria). In: Documents des Laboratoires de Géologie, Lyon, n°164, 2008. Mid-Mesozoic life and environments. Cognac (France), June 24th-28th 2008. pp. 15-18
First occurrence of a phacopid trilobite faunule from the Upper Devonian of Saoura Valley, Algeria and biodiversity fluctuations â Erratum
Famennian rhynchonellides (Brachiopoda) from deep-water facies of the Ougarta Basin (Saoura Valley, Algeria)
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