, Volume 35, Issue 1, pp 59–79 | Cite as

Depth-related ecological zonation of a carboniferous carbonate ramp: Upper Viséan of Béchar Basin, Western Algeria

  • Achour Madi
  • Pierre-André Bourque
  • Bernard L. Mamet


Following the demise of the stromatoporoid-coral reef community in Late Frasnian time, Lower Carboniferous carbonate shelf profiles possessed a ramp geometry, with major organic buildups represented by mud-rich mounds. Microfacies petrography of the exceptionally well-preserved Upper Viséan (Lower Carboniferous) carbonate ramp of the Béchar Basin, Algerian Sahara, may well contribute significantly to our understanding of the paleoecological zonation of Carboniferous non-rimmed platforms, and of the still enigmatic mounds commonly referred to as Waulsortian banks or mounds.

Facies are grouped into two broad groups: (a) a mound facies group which comprises sponge wackestone-bafflestone, sponge-fenestellid bafflestone-wackestone, crinoid wackestone-packstone, and bedded flanks of intraclastic wackestone-packstone, all four facies composing the actual mud-rich mounds, and (b) a supramound facies group composed of coral-microbial framestone, crinoid packstone-grainstone, algal-foraminiferal grainstone and oolite grainstone.

Calcareous algae are important bathymetric indicators and are used to delineate three bathymetric zones based on light penetration: the aphotic zone, which contains no calcareous algae; the dysphotic zone, where there is little ambient light, and which is characterized by the presence of red algae (Fasciella, Ungdarella, Stacheia, Epistacheoides) and absence of green algae; and the euphotic zone, which receives the full spectrum of sunlight, and is characterized by the occurrence of both green algae (Koninckopora, Kamaenella, Kamaena, Palaeoberesella, Calcisphaera, Anthracoporellopsis, Issinella, Exvotarisella) and red algae.

Integration of algal zonation, distribution of the other biota, and recurrence of distinct assemblages, enable recognition of seven depth-related benthic assemblages. Together with the physical properties of the facies, the benthic assemblages were used to define seven bathymetric zones, from upper to lower ramp: (1) algal assemblage (upper ramp); (2) crinoid-ramose bryozoan assemblage (mid-ramp); and (3) productid brachiopod assemblage, (4) colonial rugose coral-microbial encruster assemblage, (5) crinoid-fenestellid assemblage, (6) sponge-fenestellid, and (7) sponge assemblage (lower ramp).

The vertical zonation of the mud-rich mounds and associated facies differ from that reported from the classical Upper Tournaisian-Lower Viséan Waulsortian mound-bearing successions.


Carbonate Ramp Facies Analysis Petrography Paleoecological Zonation Paleobathymetric Zones Benthic Assemblages Sponges Bryozoans Calcareous Algae Crinoids Corals Microbial Incrusters Brachiopods Béchar Basin (Algeria) Carboniferous (Upper Visean) 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Ahr, W.M. (1989): Sedimentary and tectonic controls on the development of an early Mississippian carbonate ramp, Sacramento Mountains area, New Mexico.—Soc. Econ. Paleont. and Miner., Spec. Publ.44, 203–212, TulsaGoogle Scholar
  2. Bourrouilh, R. &Bourque, P.-A. (1995): Marqueurs d’évolution de marges continentales paléozoïques: les monticules carbonatés à stromatactis.—Bull. Soc. Géol. France,166, 711–724, ParisGoogle Scholar
  3. Bourque, P.-A., Amyot, G., Desrochers, A., Gignac, H., Gosselin, C., Lachambre, G. &Laliberté, J.-Y. (1986): Silurian and Lower Devonian reef and carbonate complexes of the Gaspé Basin, Québec—a summary.—Bull. Canad. Petrol. Geol.,34, 452–489, CalgaryGoogle Scholar
  4. Bourque, P.-A. &Boulvain, F. (1993): A model for the origin and petrogenesis of the red stromatactis limestone of Paleozoic carbonate mounds.—J. Sediment. Petrol.,63, 607–619, TulsaGoogle Scholar
  5. Bourque, P.-A., Madi, A. &Mamet, B.L. (1995): Waulsortian-type bioherm development and response to sea-level fluctuations: Upper Viséan of Béchar Basin, Western Algeria.—J. Sediment. Res.,B65, 80–95, TulsaGoogle Scholar
  6. Bridges, P.H. &Chapman, A.J. (1988): The anatomy of a deepwater mudmound complex to the southwest of the Dinantian platform in Derbyshire, UK.—Sedimentology,35, 139–162, OxfordCrossRefGoogle Scholar
  7. Burchette, T.P. (1981): European Devonian reefs: a review of current concepts and models. In:Toomey, D.F. (ed.): European Fossil Reef Models.—Soc. Econ. Paleont. and Miner., Spec. Publ.30, 85–142, TulsaGoogle Scholar
  8. Byers, C.W. (1977): Biofacies patterns in euxinic basins: a general model.—In:Cook, H.E. & Enos, P. (eds.): Deepwater Carbonate Environments.—Soc. Econ. Paleont. and Miner., Spec. Publ.25, 5–17, TulsaGoogle Scholar
  9. Cayeux, L. (1935): Les roches sédimentaires de France; roches carbonatées.—Paris (Masson), 463 p.Google Scholar
  10. Chatellier, J.Y. (1988): Carboniferous carbonate ramp, the Banff Formation, Alberta, Canada.—Bull. Centres Recherches, Exploration & Production, Elf-Aquitaine,12, 569–599, PauGoogle Scholar
  11. Cuffey, R.J. (1977): Bryozoan contributions to reefs and bioherms through geologic time. In:Frost, S.H., Weiss, M.P. & Saunders, J.B. (eds.): Reefs and related carbonates, ecology and sedimentology.—Am. Assoc. Petrol. Geol., Studies in Geology4, 181–194, TulsaGoogle Scholar
  12. Cuffey, R.J. (1985): Expanded reef-rock textural classification and the geologic history of bryozoan reefs.—Geology,13, 307–310, BoulderCrossRefGoogle Scholar
  13. Geldsetzer, H.H.J., James, N.P. & Tebbutt, G.E. (1988): Reefs-Canada and Adjacent Areas.—Canad. Soc. Petrol. Geol., Mem.13, 775 p., CalgaryGoogle Scholar
  14. James, N.P. (1984): Reefs. In:Walker, R.G. (ed.): Facies Models. —Geoscience Canada, 229–244, TorontoGoogle Scholar
  15. James, N.P. & Bourque, P.-A. (1992): Reefs and Mounds.—In:Walker, R.G. & James, N.P. (eds.): Facies Models—Response to Sea-Level Change.—Geol. Assoc. Canada, 323–347, St. John’sGoogle Scholar
  16. James, N.P. & Ginsburg, R.N. (1979): The seaward margin of Belize barrier and atoll reefs.—Spec. Publ. Int. Assoc. Sedimentologists3, 191 p., OxfordGoogle Scholar
  17. Jones, B. &Hunter, I.G. (1991): Corals to rhodolites to microbialites —A community replacement sequence indicative of regressive conditions.—Palaios,6, 54–66, TulsaGoogle Scholar
  18. Krebs, W. (1974): Devonian carbonate complexes of central Europe.—In:Laporte, L.F. (ed.): Reefs in Time and Space. —Soc. Econ. Paleont. and Miner., Spec. Publ.18, 155–208, TulsaGoogle Scholar
  19. Lees, A., Hallet, V. &Hibo, D. (1985): Facies variation in Waulsortian buildups, Part 1; a model from Belgium.—Geol. J.,20, 133–158, ChichesterCrossRefGoogle Scholar
  20. Lees, A. &Miller, J. (1985): Facies variation in Waulsortian buildups, Part 2; Mid-Dinantian buildups from Europe and North America.—Geol. J.,20, 159–180, ChichesterCrossRefGoogle Scholar
  21. Legrand-Blain, M. (1973): Les Gigantoproductidés (Brachiopodes) du Sahara algérien). I. Gigantoproductidés viséens.—Bull Soc. Histoire Naturelle Afrique du Nord,64, 79–158, AlgerGoogle Scholar
  22. Legrand-Blain, M. &Poncet, J. (1991): Encroûtements et perforations de tests de Brachiopodes dans le Carbonifère du Sahara algérien: implications pour la reconstitution des environnements.—Bull. Soc. Géol. France,162, 775–789, ParisGoogle Scholar
  23. Luchinina, V.A. (1987): Blue-green algae (Cyanobacteria) [in Russian].—In:Dubatolov, V.I. (ed.): Fossil calcareous algae.—Akademia Nauk S.S.S.R., Sibirskoe Otledenie, Trudy Institut Geologii i Geofiziki,674, 12–38Google Scholar
  24. Madi, A. (1994): Les bioconstruction carbonifères du bassin de Béchar, Sahara algérien: sédimentologie, diagenèse et potentiel pétrolifère.—unpublished Ph.D. thesis, Laval University, 312 p., Québec.Google Scholar
  25. Mamet, B.L. (1974): Une zonation par Foraminifères du Carbonifère inférieur de la Téthys occidentale.—Septième Congrès International de Stratigraphie et de Géologie du Carbonifère (1971),3, 391–407, KrefeldGoogle Scholar
  26. Mamet, B.L. &Boulvain, F. (1992): Microflore des monticules micritiques frasniens “F2j” de Belgique.—Rev. Micropaléontologie,35, 283–302, ParisGoogle Scholar
  27. Mamet, B.L., Roux, A., Lapointe, M. &Gauthier, L. (1992): Algues ordoviciennes et siluriennes de l’Iled’Anticosti (Québec, Canada).—Rev. Micropaléontologie,35, 211–248, ParisGoogle Scholar
  28. Mamet, B., Madi, A., Bourque, P.-A. &Sebbar, A. (1995): Foraminifères carbonifères du Grand Erg occidental, bassin de Béchar, Algérie.—Bull. Soc. Géol. Belgique,103, 51–61, BruxellesGoogle Scholar
  29. Playford, P.E. (1980): Devonian “Great Barrier Reef” of Canning Basin, Western Australia.—Am. Assoc. Petrol. Geol. Bull.,64, 814–840, TulsaGoogle Scholar
  30. Read, J.F. (1982): Carbonate platform of passive (extensional) continental margins: types, characteristics and evolution.— Tectonophysics,81, 195–212, AmsterdamCrossRefGoogle Scholar
  31. Reitner, J., Neuweiler, F. & Gautret, P. (1995): Modern and fossil automicrites: implications for mud mound genesis.— In:Reitner, J. & Neuweiler, F. (eds.): A Polygenetic Spectrum of Fine-grained Carbonate Buildups.—Facies,32, 4–17, ErlangenGoogle Scholar
  32. Sommerville, I.D., Strank, A.R.E. &Welsh, A. (1989): Chadian fauna and flora from Dyserth: depositional environments and palaeogeographic setting of Viséan strata in northeast Wales. —Geol. J.,24, 49–66, ChichesterCrossRefGoogle Scholar
  33. Tucker, M.E. &Wright, V.P. (1990): Carbonate Sedimentology. —482 p., Oxford (Blackwell)Google Scholar
  34. Wray, J.L. (1977a): Calcareous Algae.—Developments in Paleontology and Stratigraphy4, 185 p., Amsterdam (Elsevier)Google Scholar
  35. Wray, J.L. (1977b) Late Paleozoic calcareous red algae.—In:Flügel, E. (ed.) Fossil Algae. Recent Results and Developments. —167–176, Berlin (Springer)Google Scholar
  36. Wright, V.P. (1986): Facies sequence on a carbonate ramp: the Carboniferous Limestone of South Wales.—Sedimentology,33, 221–241, OxfordCrossRefGoogle Scholar
  37. Wright, V.P. &Faulkner, T.J. (1990): Sediment dynamics of Early Carboniferous ramps: a proposal.—Geol. J.,25, 139–144, ChichesterGoogle Scholar

Copyright information

© Institut für Paläontologie, Universität Erlangen 1996

Authors and Affiliations

  • Achour Madi
    • 1
  • Pierre-André Bourque
    • 1
  • Bernard L. Mamet
    • 2
  1. 1.Département de GéologieUniversité LavalQuébecCanada
  2. 2.Département de GéologieUniversité de MontréalMontréalCanada

Personalised recommendations