A review of the pre-Permian geology of the Variscan French Massif Central

The Massif Central, like the southern part of the Massif Armoricain, belongs to the north Gondwana margin. The Massif Central consists of a stack of nappes resulting from six main tectonic-metamorphic events. The first, D-0, is coeval with a Late Silurian (ca 415 Ma) high-pressure (HP) (or ultra high-pressure) metamorphism for which the associated structures are poorly documented. The Early Devonian D-1 event, responsible for top-to-the-southwest nappe displacement, is coeval with migmatization and the exhumation of HP rocks around 385-380 Ma. In the northern part of the Massif Central, metamorphic rocks with retrogressed eclogites are covered by Late Devonian undeformed sedimentary rocks. The Late Devonian-Early Carboniferous D-2 event involves top-to-the-northwest shearing, coeval with an intermediate pressure-temperature metamorphism dated around 360-350 Ma. The Visean D-3 event is a top-to-the-south ductile shearing, which is widespread in the southern Massif Central. Coevally, in the northern Massif Central, the D-3 event corresponds to the onset of synorogenic extension. The next two events, D-4 and D-5, of Early and Late Carboniferous age, correspond to the syn- and late orogenic extensional tectonic regimes, respectively. The former is controlled by NW-SE stretching whereas the latter is accommodated by NNE-SSW stretching. These structural and metamorphic events are reconsidered in a geodynamic evolution model. The possibilities of one or two cycles involving microcontinent drifting, rewelding and collision are discussed. To cite this article: M. Faure et al., C. R. Geoscience 341 (2009). (C) 2008 Academie des sciences. Published by Elsevier Masson SAS. All tights reserved.