NORTHWARD VERGING TECTONICS IN THE DEVONIAN-DINANTIAN OF NE FRENCH MASSIF-CENTRAL AND THE CLOSURE OF THE RHEIC OCEAN

In the NE part of the French Massif Central, the Devonian-Dinantian se ries exhibits a wide diversity. The major break lies in the Middle Vis ean since upper units are never ductilely deformed. In the Morvan, the Devonian Somme series, which corresponds to a magmatic are, is undefo rmed. Conversely, the Brevenne-Violay-Beaujolais series, which corresp onds to a rift zone with locally oceanic crust, is deformed by two duc tile events. The first deformation occurred before Early Visean. It is characterized by a flat-lying foliation and top-to-the-NW ductile she aring associated with the thrusting of mafic rocks upon gneissic basem ent. This deformation is coeval to the northward-verging tectonics rel ated to the closure of the Rheic ocean.