Lithospheric structure and tectonic memory of the European Variscan belt

The Variscan belt of Europe formed during the late Paleozoic through the convergence of Laurussia and Gondwana, subduction of intervening oceans, and the accretion of peri-Gondwanan terranes during Pangaea assembly. This study integrates geological, geophysical and crust–mantle structural data to investigate the orogen's construction, destruction and post-orogenic modifications. Key tectonic features include high-pressure metamorphic nappes in the internal zone and partially preserved sutures in the external zones. Crustal and lithospheric mantle thickness and gravity anomalies reveal distinct tectonic domains: the Bohemian Massif retains a thick crust with north- and south-directed subduction structures, while the French Massif Central and Iberian Massif reveal north-directed subduction, lithospheric thinning and gravitational collapse due to slab retreat. These patterns support a bivergent tectonic model involving south-dipping subduction and tectonic accretion in the north, and southward slab rollback of a north-dipping slab with horizontal flow of partially molten crust in the south. Despite later modifications the thin lithosphere beneath the Variscan internal zone is interpreted as a remnant of the Variscan architecture, as attested by the petrological–geochemical record of mantle xenoliths. The present-day structure of the European lithosphere thus provides a critical framework for reconstructing the Variscan orogen's tectonic evolution and understanding long-term lithospheric inheritance.