Geologica Belgica Geologica Belgica -  volume 9 (2006)  number 1-2 - Chronostratigraphic units named from Belgium 

GIVETIAN

Alain PREAT
Université Libre de Bruxelles, Département des Sciences de la Terre et de l’Environnement, Géologie-CP160/02, 50 av FD Roosevelt, B 1050 Bruxelles, Belgique; E-mail: apreat@ulb.ac.be.
Pierre BULTYNCK
Royal Belgian Institute of Natural Sciences, Department of Palaeontology, Vautierstraat, 29, B-1000 Brussels, Belgium; E-mail: pierre.bultynck@belgacom.net.
Denise BRICE
Laboratoire de Paléontologie stratigraphique, Faculté Libre des Sciences, rue de Toul, 13, F-59046 Lille cedex, France; E-mail: denise.brice@fls.fupl.asso.fr.

Abstract

The Givetian Stage in the Givet area is represented by the main part of the Hanonet Fm, the Trois-Fontaines Fm, the Terres d'Haurs Fm, the Mont d'Haurs Fm, the Fromelennes Fm and the lowest part of the Nismes Fm. During Eifelian-Givetian transition, the sedimentary systems evolved from a mixed siliciclastic-carbonate ramp to a carbonate platform dominated by cyclic tidal-flat and lagoonal wackestones with local patch reefs or coralgal banks. The shelf had an ESE-WNW trend and extended from the Avesnois basin (northern France) in the west to Aachen (western Germany). The sedimentation in the Ardennes consists of shallow water regressive metric (around 5 m or less) cycles. Stromatopores, corals, brachiopods, algae and cyanobacteria are abundant. Due to this general shallow water setting, the base of the Givetian Stage has been defined by the IUGS Subcommission on Devonian Stratigraphy in a GSSP in southern Morocco referring to the first occurence of the condodont species Polygnathus hemiansatus. The conodont species Icriodus obliquimarginatus appears approximately at the same level in Belgium.

Keywords : Givetian, lagoons, tidal flats, patch reefs, coralgal banks, carbonate platform

Para citar este artículo

Alain PREAT, Pierre BULTYNCK & Denise BRICE, «GIVETIAN», Geologica Belgica [En ligne], volume 9 (2006), number 1-2 - Chronostratigraphic units named from Belgium, 9-18 URL : https://popups.uliege.be/1374-8505/index.php?id=1063.