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Two eclogite samples from the Haut‐Allier record a prograde evolution from ~20 kbar, 650°C to 750°C, 22–23 kbar followed by heating up to 850–875°C and partial melting. Incipient decompression in high‐pressure granulite facies conditions (19.5 kbar, 875°C) was followed by exhumation to high‐temperature amphibolite facies conditions (<9 kbar, 750–850°C). Following a detailed geochemical, petrological, and geochronological investigation using trace‐element data and laser ablation inductively coupled plasma mass spectrometry U–Pb dating of zircon, apatite, and rutile, the eclogites reveal an Ordovician (c. 490 Ma) rifting event followed by Devonian (c. 370–360 Ma) subduction and Carboniferous (c. 350 Ma) exhumation in this part of the French Massif Central. The previously proposed Silurian age for the subduction, which strongly influenced many tectonic models, is definitively rejected. In the light of other geological data from the French Massif Central, including the lithological and geochemical zoning of calc‐alkaline Devonian volcanism, we propose a southward polarity of the subduction and question the very existence of the so‐called Massif Central Ocean. Furthermore, we infer that following subduction, the eclogites were relaminated to the upper plate and exhumed at the rear of the magmatic arc pointing to similarities with the geodynamics of the Bohemian Massif. The petrochronological record of zircon is particularly complex. Metamorphic zircon with clear eclogitic rare‐earth elements patterns (no Eu anomaly and flat heavy rare‐earth elements) and inclusions (garnet, rutile, and omphacite) shows concordant apparent ages that spread from c. 380 down to c. 310 Ma. This apparent age pattern strongly contrasts with the well‐defined age of apatite and rutile of c. 350 Ma. Apparent zircon ages younger than 350 Ma unequivocally testify that zircon can recrystallize outside the conditions of the eclogite facies, which resets the U–Pb while preserving an apparent eclogitic signature. Local fractures filled by analcite, thomsonite, plagioclase, and biotite testify to late interaction of the eclogites with alkaline fluids at relatively low temperatures. This interaction, possibly at c. 310 Ma or later, could lead to the recrystallization of zircon while leaving apatite unaffected. [ABSTRACT FROM AUTHOR]

The French Massif Central (FMC) forms the hinterland of the west-European Variscan belt and was subject to numerous tectonic and metamorphic events from Devonian to Permian times. The accreted tectonic units belonging to Gondwana and Laurussia were variably involved in subduction, nappe stacking and syn- to post-orogenic extension. Besides, plutons and migmatites showing syn-collision crust melting are very common in the Variscan belt. Such orogenic evolution implies that the resulting finite structure likely reflects the interference between fabrics formed at different stages of the orogenic cycle with different degrees of overprinting, depending on e.g. the spatial strain gradients, lithologies, structural level or partial melting grade.We present a model of finite strainfield of the western FMC based of the analysis/interpolation of ductile and brittle fabrics, at regional to local scale, using geostatistics. Ductile fabrics within autochthonous units and syn-collisional plutons are poorly disturbed and reflect the transition from syn-thickening to extensional lateral flow of the partially molten mid-lower crust. In contrast, allochtonous units are affected by numerous perturbations including polyphased ductile shearing, folding and faulting inducing local bloc tilting and rotations. Taking into account the overprint of late tectonic events, we show that early fabrics related to High Pressure metamorphism or nappes' stacking have suffered intense reorientations. The finite trend of the related lineations L1 must be treated with extreme caution and may not reflect the original direction of stretching and shearing that occurred during the initial compressional stages. Taking into account i) the spatial distribution and amount of reorientation of these D1 fabrics and ii) the deconvolution of these disturbances, we propose that:- The high dispersion of lineation trend can be simply explained by passive rotations, during late isoclinal folding, rather than two superposed tectonic phases, as previously inferred. - The allochtonous units formed one single tectonic unit. - This D1 event looks related to the exhumation of the subducted continental crust due to partial melting- The formation of Variscan orogenic prism in western FMC only results of continuous south-directed thrusting rather than a switch from NE-SW to NW-SE thrusting. [ABSTRACT FROM AUTHOR]