The early land plants from the Armorican Massif: sedimentological and palynological considerations on age and environment

Christine Strullu-Derrien (1, 2) , Céline Ducassou (3) , Michel Ballevre (3) , Marie-Pierre Dabard (3) , Philippe Gerrienne (2) , Alain Le Hérissé (4) , Cécile Robin (3) , Philippe Steemans (2) , Désiré-Goerges Strullu (1) , Hubert Lardeux

1 Laboratoire Mycorhizes
2 Paléobotanique, Paléopalynologie et Micropaléontologie
3 GR - Géosciences Rennes
4 LDO - Domaines Océaniques

The Châteaupanne Unit belongs to the South Armorican domain of the Armorican Massif (France), which is part of the Variscan belt. This unit includes two Lower Devonian plant levels and one of them corresponds to the Basal Member of the Chalonnes Formation. A sedimentological and palaeontological analysis of these fossiliferous deposits from the Châteaupanne quarry (Montjean/Loire, Maine et Loire, France) is presented here for the first time. The age determination based on palynology indicates that the locality records the earliest occurrence of plant megafossils in the Armorican Massif. Their presence suggests an emergence event that has never been described before. Our study highlights the promising potential of the Basal Member of the Chalonnes Formation to aid in understanding these occurrences, and provides new insights into the history of the Variscan belt.

Mots clés: early land plants; Lower Devonian; spores; acritarchs; emergence event; unconformity; storm

Domaines: Paléontologie

Christine Strullu-Derrien, Céline Ducassou, Michel Ballevre, Marie-Pierre Dabard, Philippe Gerrienne, et al.. The early land plants from the Armorican Massif: sedimentological and palynological considerations on age and environment. Geological Magazine, 2010, 147 (6), pp.830-843. ⟨10.1017/S001675681000004X⟩. ⟨insu-00530313⟩