Hercynian polyphase tectonics in the northeast French Massif Central: the closure of the Brévenne Devonian–Dinantian rift     

C. Leloix  M. Faure  J.-L. Feybesse 《International Journal of Earth Sciences》1999,88(3):409-421

 Field and laboratory structural studies show that the Devonian–Dinantian units of the northeast French Massif Central experienced a complex and contrasting tectonic–metamorphic evolution during the Hercynian orogeny. The structural analysis of the pre-Middle Visean Brévenne–Violay–Beaujolais rocks, in the Loire area, shows a polyphase tectonic evolution associated with greenschist to amphibolite facies metamorphism. The first event, D1, probably occurred in Early Tournaisian or Latest Devonian times. It is responsible for the flat-lying regional foliation and the NW/SE- to N/S-trending lineation. It is well observed in the Violay group and corresponds to the NW-vergent emplacement of the Late Devonian units upon their gneissic basement, represented by the Affoux gneisses. The second event, D2, is responsible for the NE/SW- to E/W-trending lineation. To the south, D2 deformation is locally reworked by the Grand-Chemin dextral wrench fault, around 345–350 Ma ago. This polyphase deformation is also found in several Devonian–Dinantian areas of the NE Massif Central, but not in Morvan. This tectonics corresponds to the Tournaisian closure, by northward thrusting and subsequent intracontinental deformation, of the oceanic Brévenne–Violay–Beaujolais rift which opened in Devonian times in a back-arc setting. Received: 4 September 1998 / Accepted: 27 May 1999  相似文献   

Late Visean thermal event in the northern part of the French Massif Central: new 40Ar/39Ar and Rb–Sr isotopic constraints on the Hercynian syn-orogenic extension     

Michel Faure  Patrick Monié  Christian Pin  Henri Maluski  Christele Leloix 《International Journal of Earth Sciences》2002,91(1):53-75

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