Two Distinct Metasomatized Mantle Sources Produced Two Groups of Alkaline SiO2-Undersaturated Rocks in the Southern Central European Volcanic Province.

This article focuses on the petrology, geochemistry, and geodynamic context of Upper Cretaceous–Miocene alkaline SiO₂-undersaturated volcanic rocks in the southern Central European Volcanic Province (CEVP). It identifies two distinct volcanic rock series: (i) Upper Cretaceous–Eocene (~73–47 Ma) olivine nephelinites, basanitic nephelinites, and nepheline basanites derived from partial melting of amphibole-bearing garnet/spinel lherzolite metasomatized by hydrous melts or fluids near the lithosphere–asthenosphere boundary; and (ii) Oligocene–Miocene (~27–9 Ma) olivine melilitites and melilite-bearing olivine nephelinites originating from less than 3.5% partial melting of amphibole ± phlogopite-bearing garnet wehrlite in the upper asthenosphere, influenced by carbonatitic metasomatism. Both volcanic episodes coincide with lithospheric uplift, erosion, rifting, and fault reactivation linked to Alpine orogeny-related crustal dynamics, with magma genesis controlled by mantle metasomatism and lithosphere–asthenosphere interaction rather than deep mantle plumes.