Summary
In the castern Anti-Atlas (SE Morocco), a small sedimentary basin (Mader Basin) evolved during the late Palacozoic. The Middle Devonian deposits consist of shales and limestones with a thickness up to 700 m in the depocentre. Sedimentary structures and sole marks of Middle Devonian limestones indicate transport from the northwest and the south towards the basin centre, located in the central Mader area. Lithostratigraphic, biostratigraphic, and dynamic stratigraphic approaches were applied to correlate stratigraphic sections. Five correlatable large-scale base-level hemicycles were recognized in the Middle Devonian succession. Thickness trends of Middle Devonian deposits, regional correlations, and facies-trends reveal the geometry of a carbonate ramp. The carbonate ramp was slightly inclined (<1°) to the NE. A sedimentary wedge, consisting of limestones and limestone/marl alternations, was deposited during the Eifelian and marks the transition from the ramp to the adjacent basin. Middle Devonian water depths are estimated as close to and within the storm wave-base at the southern area of the ramp and far below storm wave-base in the northeastern part of the ramp. Shallowest conditions (inner-ramp environment), close or within the fairweather wave-base, existed during the early Givetian as documented by the abundance of recfal fauna (stromatoporoids, corals) and calcimicrobes (lumps, micritic envelopes) in the eastern and southeastern area of the ramp.
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References
Cross, T.A. & Lessenger, M.A. (1998): Sediment volume partitioning: Rationale for stratigraphic model evaluation and high-resolution stratigraphic coreelation.—In: Gradstein, F.M., Sandvik, K.O. & Milton, N.J. (eds.): Sequence stratigraphy concepts and applications.—Norwegian Petr. Soc., Spec. Publ.,8, 171–195, Amsterdam
Dunham, R.J. (1962): Classification of carbonate rocks according to depositional texture.—In: Ham, W.E. (ed.): Classification of carbonate rocks.—Am. Assoc. Petr. Geol. Mem.,1, 108–121. Denver
Füchtbauer, H & Richter, D. K. (1983): Relations between submarine fissures, internal breccias and mass flows during Triassic and earlier rifting periods.—Geol. Rundsch.,72, 53–66, Berlin
Hollard, H. (1974): Recherches sur la stratigraphie des formations du Dévonien moyen, de l'Emsien supérieur au Frasnien, dans le Sud du Tafilalt et dans le Ma'der, (Anti-Atlas oriental.—Notes Serv. Géol. Maroc.,36, 264, 7–68, Rabat
Homewood, P.W. (1996): The carbonate feedback system: interaction between stratigraphic accomodation, ecological succession and the carbonate factory.—Bull. Soc. Géol. France,167, 6, 701–715, Paris
Jacobshagen, V. (1992): Major fracture zones of Morocco: The South Atlas and the Transalboran fault systems.—Geol. Rundsch.,81, 1, 185–197, Berlin
Kaufmann, B. (1998): Facies, Stratigraphy and Diagenesis of Middle Devonian Reef-and Mud-Mounds in the Mader (eastern Anti-Atlas, Morocco).—Acta Geol. Polonica,48, 1, 43–106, Warsaw
Kazmierczak, M. & Schröder, S. (1999): Faziesentwicklung, relative Meeresspiegelschwankungen und die Migration von Korallenfaunen im östlichen Anti-Atlas, Marokko.—Zbl. Geol. Paläont. Teil 1,7–9, 1177–1188, Stuttgart
Massa, D. (1965): Observations sur les séries Siluro-Dévoniennes des confins Algéro-Marocains du sud.—Notes Mém. Comp. Franc. Pétrol.,8, 1–187, Paris
Michard, A, Yazidi, A, Benziane, F., Hollard, H. & Willefert, S. (1982): Foreland thrusts and olistromes (sic !) on the pre-Sahara margin of the Variscan orogen, Morocco.—Geology,10, 253–256, Boulder
Piqué, A. & Michard, A. (1989): Moroccan Hercynides: a synopsis. The Paleozoic sedimentary and tectonic evolution at the northern margin of West Africa.—Am. J. Sci.,289, 286–330, New Haven
Stets, J. & Wurster, P. (1988): Atlas and Atlantic—structural relations.—In: Jacobshagen V.H. (ed.): The Atlas system of Morocco, studies on its geodynamic evolution.—Lect. Notes in Earth Sci.,15, 219–244, Berlin
Walker, K.R. & Alberstadt, L.P. (1975): Ecological succession as an aspect of structure in fossil communities.—Paleobiology,1, 238–257, Ithaca
Wendt, J. (1993): Steep sided carbonate mud mounds in the Middle Devonian of the eastern Anti-Atlas, Morocco.—Geol. Mag., 130, 69–83, London
Wendt, J. (1988): Facies pattern and palaeogeography of the Middle and Late Devonian in the eastern Anti-Atlas (Morocco). —McMillan, N.J., Embry, A.F., Glass, D.J. (eds.): Devonian of the world.—Proc. 2nd Int. Symp. Devonian System, Calgary,1, 467–479, Calgary
Wendt, J. & Belka, Z. (1991): Age and depositional environment of Upper Devonian (early Frasnian to early Famenian) black shales and limestones (Kellwasser facies) in the eastern Anti-Atlas, Morocco.—Facies,25, 51–90 Erlangen
Wheeler, H.E. (1964): Base-level, lithosphere surface, and time-stratigraphy.—Geol. Soc. Am. Bull.,75, 599–610, Boulder
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Doring, S., Kazmierczak, M. Stratigraphy, geometry, and facies of a Middle Devonian ramp-to-basin transect (Eastern Anti-Atlas, SE Morocco). Facies 44, 137–150 (2001). https://doi.org/10.1007/BF02668171
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DOI: https://doi.org/10.1007/BF02668171