Paleozoic tectonic evolution of medio-Europa from the example of the French Massif Central and Massif Armoricain

P–T paths reconstruction of a collisional event: The example of the Thiviers-Payzac Unit in the Variscan French Massif Central

“…[Matte, 1991], [Ledru et al, 1989], [Faure et al, 1997] and [Faure et al, 2005]). From south to north, and from bottom to top, the following units are recognized ( Fig.…”

“…Indeed, several contradictory models have been proposed to explain the top-to-the NW shearing. The D2 event has been related either to transpressional tectonics during a single orogenic cycle (Brun and Burg, 1982), or to nappe thrusting (Bouchez and Jover, 1986), or to syn-orogenic extension (Mattauer et al, 1988), or to a second compressional cycle after a short period of rifting during Upper Devonian ( [Faure et al, 1997] and [Faure et al, 2005]). Thus, to reconstruct P-T paths experienced by different units is a crucial point to decipher the tectonic setting of the D2 event or, in other words, to know whether the D2 event took place during an extensional tectonic setting or during a compressional one.…”

“…This D1 event is related to the collision between Gondwana to the south and Armorica to the north (e.g. [Matte, 1991], and [Faure et al, 2005]). The top-to-the NW event (D2) occurred in Late Devonian -Early Carboniferous times and reworks the stack of nappes previously formed by the D1 event.…”

Gravity inversion, AMS and geochronological investigations of syntectonic granitic plutons in the southern part of the Variscan French Massif Central

“…Although the Omps pluton appears as ca 10 Ma older than the other two, the petrological similarities and the spatial proximity of the Boisset and Omps plutons suggest that these plutons emplaced from late Visean to Namurian during the same tectono-metamorphic event. The tectonic setting of the Middle to Late Carboniferous magmatic event in the FMC has already been described (e. g. Faure 1995;Faure et al 2005). Therefore, a similar tectonic setting seems likely to account for the emplacement of all these plutons.…”

“…It is now well established that several ductile thrusting events in the FMC took place in the Devonian and Early Carboniferous (e.g. Ledru et al 1989;Faure et al 2005 and enclosed references). In the late Visean time (ca 335 Ma), the onset of the syn-orogenic extension occurred (Van den Driessche and Brun 1989) and was coeval with magmatism in the northern part of the FMC.…”