A geological synthesis of the Palaeozoic Vosges Mountains (NE France) is presented using existing observations and new data. The geodynamic evolution involves: (1) Early Palaeozoic sedimentation and magmatism; (2) Late Devonian subduction triggering back-arc spreading; (3) early Lower Carboniferous continental subduction, continent–continent collision and polyphase deformation and metamorphism of the orogenic root; and (4) late Lower Carboniferous orogenic collapse driven by thermal weakening of the middle crust. The evolution is integrated within the framework of the European Variscan Belt. The Northern Vosges comprise sediments of Rhenohercynian affinity separated from Teplá-Barrandian metasediments by a Lower Carboniferous magmatic arc. The latter is correlated with the Mid-German Crystalline Rise, and is ascribed to the south-directed subduction of the Rhenohercynian Basin. The Saxothuringian–Moldanubian suture is thought to be obliterated by the magmatic arc, while the Lalaye–Lubine Fault is interpreted as the Teplá-Barrandian–Moldanubian boundary. The Central Vosges are paralleled with the Moldanubian domain of the Bohemian Massif where identical lithologies record the Devonian–Carboniferous SE-directed subduction of the Saxothuringian passive margin below the Moldanubian upper plate. The Southern Vosges represent the upper Moldanubian crust and are linked to the southern Black Forest. The presence of an oceanic domain to the south of the Vosges–Black Forest remains unclear.Supplementary material:List of radiometric ages used for probability plots is available at http://www.geolsoc.org.uk/SUP18734.

Plutonic bodies of the Central and Southern Vosges Mts can be assigned to two major early Carboniferous magmatic events: a Visean Mg–K event ( c. 345 and 340–336 Ma) and a younger S-type event (329–322 Ma). New petrological, geochemical and Sr–Nd isotopic data highlight the existence of two groups of Mg–K intrusions that might be related to the nature of their primary magma sources; that is, CHUR-like and enriched mantle, which interacted with juvenile and mature crustal material, respectively. The differences between these two groups are explained by a geodynamic scenario involving deep subduction and relamination of the Saxothuringian continental crust under the Moldanubian continent. The relaminated radiogenic Saxothuringian material is thought to have been responsible for dehydration melting of both subducted crust and underlying metasomatized mantle, thereby generating the Mg–K magma subsequently emplaced at middle crustal depth. During their ascent, the mafic magmas interacted with crustally derived felsic melts. Significantly later ( c . 10–15 myr) a widespread mid-crustal anatexis occurred, generating voluminous granite intrusions from mixed crustal sources (paragneisses and/or immature felsic–intermediate metaigneous rocks mixed with Mg–K plutons). The principal heat source for such a major melting event is related to the presence of Mg–K plutons rich in heat-producing elements, which were responsible, after the time lag specified, for a temperature increase at mid-crustal levels by in situ radiogenic heat production. The current study underlines the importance of deep continental crust subduction and relamination for the magmatism and development of collisional orogens. Supplementary material: Analytical methods and data, and supplementary figures, are available at http://www.geolsoc.org.uk/SUP18795 .

Middle Devonian–Permian magmatic rocks from the northern Vosges Mountains show temporal and chemical variations which are linked to the continuous subduction of the Rhenohercynian oceanic crust and the Avalonian Devonian passive margin underneath the Saxothuringian continental crust. Major and trace elements and Sr–Nd isotopes of the northern Vosges basic to acidic magmatic rocks show that they evolved through time from: (1) Middle Devonian tholeiitic to calc-alkaline volcanic Rabodeau–Schirmeck sequence derived from partial melting of a depleted mantle, with these primary magmas having triggered anatexis of young crustal material of the Saxothuringian crust; (2) calc-alkaline Bande Médiane volcanic belt (c. 334 Ma), diorite and Hohwald granodiorite intrusion (c. 329 Ma) originated from enriched mantle contaminated and metasomatized by fluids expelled from a subduction zone; (3) high-K calc-alkaline Belmont granite (c. 318 Ma), whose chemical signature suggests magma-mixing between enriched mantle-derived melts and magmas from a young crustal source; (4) Mg–K Younger granite (c. 312 Ma) might be related to partial melting of enriched mantle which interacted with juvenile crustal material; and (5) Kagenfels S-type granite and Permian volcanic rocks generated by anatexis of meta-igneous and minor metasedimentary rocks.Supplementary material:Chemical analyses of biotite and amphibole of the northern Vosges rocks are available at http://www.geolsoc.org.uk/SUP18740.