The Ordovician of France and neighbouring areas of Belgium and Germany

The Ordovician successions of France and neighbouring areas of Belgium and Germany are reviewed and correlated based on international chronostratigraphic and regional biostratigraphic charts. The same three megasequences related to the rift, drift and docking of Avalonia with Baltica can be tracked in Belgium and neighbouring areas (Brabant Massif and Ardenne inliers), western (Rhenish Massif) and northeastern Germany (Rügen). The remaining investigated areas were part of Gondwana in the Ordovician. The Armorican Massif shares with the Iberian Peninsula a Furongian–Early Ordovician gap (Toledanian or Norman gap), and a continuous Mid–Late Ordovician shelf sedimentation. The Occitan Domain (Montagne Noire and Mouthoumet massifs), eastern Pyrenees and northwestern Corsica share with southwestern Sardinia continuous shelf sedimentation in the Early Ordovician, and a Mid Ordovician ‘Sardic gap’. In the Ordovician, the Maures Massif probably belonged to the same Sardo-Occitan domain. The Vosges and Schwarzwald massifs display compa-rable, poorly preserved Ordovician successions, suggesting affinities with the Teplá-Barrandian and/or Molda-nubian zones of Central Europe.This paper is a contribution to the International Geoscience Programme (IGCP) projects 653 "The onset of the Great Ordovician Biodiversification Event" and 735 “Rocks and the Rise of Ordovician Life: Filling knowledge gaps in the Early Palaeozoic Biodiversification". The authors are particularly grateful to Annalisa Ferretti, David A.T. Harper and Petr Kraft for their careful and constructive reviews, comments and suggestions, which greatly improved the quality and relevance of the paper

The supposed thrust fault in the Dyle-Thyle outcrop area (southern Brabant Massif, Belgium) re-interpreted as a folded low-angle extensional detachment

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Diagenesis of Frasnian mudmounds from the Dinant Synclinorium, Belgium

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Palaeozoic deformation history of the Asquempont-Virginal area (Brabant Massif, Belgium) : large-scale slumping, low-angle extensional detachment development (the Asquempont Fault redefined) and normal faulting (the Nieuwpoort-Asquempont fault zone)

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Faults in the Asquempont area, southern Brabant Massif, Belgium

The literature suggests that the Asquempont fault, a supposedly important reverse fault forming the limit between the Lower to lower Middle Cambrian and the Ordovician in the Sennette valley, is poorly understood. Nevertheless, this fault is commonly equated with a pronounced NW-SE-trending aeromagnetic lineament, the Asquempont lineament, and both the geometry of the Asquempont lineament and the supposed reverse movement of the Asquempont fault are used to develop large-scale tectonic models of the Brabant Massif. New outcrop observations in the Asquempont area, the "type locality" of the Asquempont fault, in combination with outcrop and borehole data from surrounding areas, show that the Asquempont fault is not an important reverse fault, but instead represents a pre-cleavage, low-angle extensional detachment. This detachment formed between the Caradoc and the timing of folding and cleavage development and is not related to the aeromagnetic Asquempont lineament. The Asquempont area also contains several relatively important, steep, post-cleavage normal faults. Apparently, these occur in a WNW-ESE-trending zone between Asquempont and Fauquez, extending westward over Quenast towards Bierghes. This zone coincides with the eastern part of the WNW-ESE-trending Nieuwpoort-Asquempont fault zone, for which, on the basis of indirect observations, previously a strike-slip movement has been proposed. Our outcrop observations question this presumed strike-slip movement. The Asquempont fault may be related to the progressive unroofing of the core of the Brabant Massif from the Silurian onwards. Possibly, other low-angle extensional detachments similar to the Asquempont fault occur in other parts of the massif. Possible candidates are the paraconformity-like contacts depicted on the most recent geological map of the Brabant Massif.status: publishe