scholarly journals Strain partitioning along the anatectic front in the Variscan Montagne Noire massif (southern French Massif Central)

Tectonics ◽  
2015 ◽  
Vol 34 (8) ◽  
pp. 1709-1735 ◽  
Author(s):  
Mickael Rabin ◽  
Pierre Trap ◽  
Nicolas Carry ◽  
Kevin Fréville ◽  
Bénédicte Cenki-Tok ◽  
...  
Keyword(s):  
French Massif Central ◽  
Strain Partitioning ◽  
Massif Central ◽  
Montagne Noire

French and Belgian Uplands

2005 ◽  
Author(s):  
Bernard Etlicher
Keyword(s):  
Continental Crust ◽  
Rift Valley ◽  
Sedimentary Basins ◽  
Shear Zones ◽  
Metamorphic Complex ◽  
French Massif Central ◽  
Massif Central ◽  
Montagne Noire ◽  
Oceanic And Continental Crust ◽  
Moderate Elevation

The French Uplands were built by the Hercynian orogenesis. The French Massif Central occupies one-sixth of the area of France and shows various landscapes. It is the highest upland, 1,886 m at the Sancy, and the most complex. The Vosges massif is a small massif, quite similar to the Schwarzwald in Germany, from which it is separated by the Rhine Rift Valley. Near the border of France, Belgium, and Germany, the Ardennes upland has a very moderate elevation. The largest part of this massif lies in Belgium. Though Brittany is partly made up of igneous and metamorphic rocks, it cannot be truly considered as an upland; in the main parts of Brittany, altitudes are lower than in the Parisian basin. Similarities of the landscape in the French and Belgian Uplands derive from two major events: the Oligocene rifting event and the Alpine tectonic phase. The Vosges and the Massif Central are located on the collision zone of the Variscan orogen. In contrast, the Ardennes is in a marginal position where primary sediments cover the igneous basement. Four main periods are defined during the Hercynian orogenesis (Bard et al. 1980; Autran 1984; Ledru et al. 1989; Faure et al. 1997). The early Variscan period corresponds to a subduction of oceanic and continental crust and a highpressure metamorphism (450–400 Ma) The medio- Variscan period corresponds to a continent–continent collision of the chain (400–340 Ma). Metamorphism under middle pressure conditions took place and controlled the formation of many granite plutons: e.g. red granites (granites rouges), porphyroid granite, and granodiorite incorporated in a metamorphic complex basement of various rocks. The neo-Variscan period (340–320 Ma) is characterized by a strong folding event: transcurrent shear zones affected the units of the previous periods and the first sedimentary basins appeared. At the end of this period, late-Variscan (330–280 Ma), autochthonous granites crystallized under low-pressure conditions related to a post-collision thinning of the crust. Velay and Montagne Noire granites are the main massifs generated by this event. Sediment deposition in tectonic basins during Carboniferous and Permian times occurred in the Massif Central and the Vosges: facies are sandstone (Vosges), shale, coal, and sandstone in several Stephanian basins of the Massif Central, with red shale and clay ‘Rougier’ in the south-western part of the Massif Central.

scholarly journals The South Millevaches Middle Carboniferous crustal melting and its place in the French Variscan belt

2009 ◽  
Vol 180 (6) ◽  
pp. 473-481 ◽  
Author(s):  
Michel Faure ◽  
Eugène Be Mezeme ◽  
Alain Cocherie ◽  
Jérémie Melleton ◽  
Philippe Rossi
Keyword(s):  
Crustal Melting ◽  
Variscan Belt ◽  
French Massif Central ◽  
The South ◽  
Massif Central ◽  
Rock Types ◽  
Fold And Thrust Belt ◽  
Three Samples ◽  
Middle Carboniferous ◽  
Montagne Noire

AbstractSeveral episodes of crustal melting are now well identified in the Variscan French Massif Central. Middle Devonian (ca 385-375 Ma) migmatites are recognized in the Upper and Lower Gneiss Units involved in the stack of nappes. Late Carboniferous migmatites (ca 300 Ma) are exposed in the Velay Massif only and Middle Carboniferous migmatites crop out in the Para-autochthonous Unit and southern Fold-and-Thrust Belt. In the SW part of the Massif Central, the South Millevaches massif exposes migmatites developed at the expense of ortho- and paragneiss. They form kilometer-sized septa within the foliated Goulles leucogranitic pluton, which is in turn intruded by the non-foliated Glény two micas granite pluton. Monazite grains extracted from these three rock-types have been dated by the EPMA chemical method. Three samples of migmatite yield a late Visean age (ca 337-328 Ma), the Goulles and Glény granitic plutons yield ages at 324-323 Ma and 324-318 Ma, respectively. These new results enlarge the evidence of a Middle Carboniferous crustal melting imprint that up to now was only reported in the eastern part of the French Massif Central, in the northern Cévennes and in the Montagne Noire axial zone. At the scale of the French Variscan massifs, the Visean crustal melting event is conspicuously developed since it is recognized from the Massif Armoricain (Vendée and south coast of Brittany) to the Central Vosges. This episode is synchronous with the huge thermal event responsible for the “Tuffs anthracifères” magmatism of the northern Massif Central and Vosges, and took place immediately after the last thickening phase recorded both in Montagne Noire and Ardennes, that is on the southern and northern outer zones of the Variscan Belt, respectively. However, the geodynamic significance of this major event is not fully understood yet.

scholarly journals Age of metamorphism and deformation in the Montagne Noire dome (French Massif Central): Tapping into the memory of fine-grained gneisses using monazite U-Th-Pb geochronology

2020 ◽  
Vol 776 ◽  
pp. 228316 ◽  
Author(s):  
Françoise Roger ◽  
Christian Teyssier ◽  
Donna L. Whitney ◽  
Jean-Patrick Respaut ◽  
Jean-Louis Paquette ◽  
...  
Keyword(s):  
French Massif Central ◽  
Massif Central ◽  
Fine Grained ◽  
Montagne Noire

Early Permian extensional shearing of an Ordovician granite: The Saint-Eutrope “C/S-like” orthogneiss (Montagne Noire, French Massif Central)

2012 ◽  
Vol 344 (8) ◽  
pp. 377-384 ◽  
Author(s):  
Pavel Pitra ◽  
Marc Poujol ◽  
Jean Van Den Driessche ◽  
Jean-Charles Poilvet ◽  
Jean-Louis Paquette
Keyword(s):  
Early Permian ◽  
French Massif Central ◽  
Massif Central ◽  
Montagne Noire

scholarly journals Deep crustal source of gneiss dome revealed by eclogite in migmatite (Montagne Noire, French Massif Central)

2020 ◽  
Vol 38 (3) ◽  
pp. 297-327
Author(s):  
Donna L. Whitney ◽  
Clémentine Hamelin ◽  
Christian Teyssier ◽  
Natalie H. Raia ◽  
Megan S. Korchinski ◽  
...  
Keyword(s):  
French Massif Central ◽  
Gneiss Dome ◽  
Massif Central ◽  
Crustal Source ◽  
Montagne Noire

scholarly journals Paleogeographic patterns of the Cambrian-Ordovician transition in the southern Montagne Noire (France) : preliminary results

2003 ◽  
Vol 174 (3) ◽  
pp. 217-225 ◽  
Author(s):  
J. Javier Álvaro ◽  
Cristina González-Gómez ◽  
Daniel Vizcaïno
Keyword(s):  
Tectonic Activity ◽  
Magmatic Activity ◽  
French Massif Central ◽  
Massif Central ◽  
Preliminary Results ◽  
Volcanic Events ◽  
Montagne Noire ◽  
Sponge Spicules ◽  
Mixed Carbonate

Abstract The Cambrian-Ordovician transition in the southern Montagne Noire records a major siliciclastic regressive trend of prograding shoaling complexes (the La Dentelle Formation), separating two transgressive storm-dominated sedimentary systems of mixed (carbonate-siliciclastic) deposits. The latter comprise the underlying La Gardie and Val d’Homs Formations, and the overlying Mounio Formation, all of them displaying evidence of an important synsedimentary tectonic activity. Isolated settings of carbonate productivity, located on intra-shelf ramps and horsts, contain the richest and diversified faunistic communities comprising trilobites, echinoderms, conodonts, carbonate- and phosphate-shell brachiopods, sponge spicules, etc. Although the Cambrian-Ordovician transition of the southern Montagne Noire did not record volcanic events but a rather distensive regime inducing paleotopographies, the latter may reflect a distinct extensional regime recorded in other earliest Ordovician platforms of the French Massif Central, involving oceanization and a major magmatic activity.

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