Extension-driven evolution of magmatic systems in slab-top basins: insights from the Timok magmatic complex, Serbian Carpathians

Slab-top basins represent key archives of the interaction between subduction dynamics, lithospheric extension, and magmatism. This study presents the first basin-scale tectono-magmatic model for the Late Cretaceous evolution of the Timok Magmatic Complex (TMC) basin, a segment of the Apuseni–Banat–Timok–Srednogorie (ABTS) magmatic belt in SE Europe. Integration of detailed structural and kinematic analyses with zircon U–Pb geochronology of syn-tectonic intrusions reveals that the TMC basin formed as a strongly asymmetric slab-top basin under E–W to NE–SW extension driven by retreat of the Neotethys slab. Early basin development was dominated by border-fault–controlled subsidence and sedimentation, followed at ∼88–87 Ma by migration of deformation into the basin interior and localization along a major intra-basin normal fault corridor in the eastern part of the basin, which focused syn-tectonic calc-alkaline magmatism and hydrothermal activity. Between ∼88 and 81 Ma, deformation and magmatism propagated laterally along strike, tracking progressive growth of the fault system, whereas after ∼81 Ma extensional deformation waned and magmatism migrated westward and became increasingly decoupled from faulting. By ∼76 Ma, the basin entered a post-rift stage marked by shallow-marine carbonate deposition and regressive molasse sedimentation. These results demonstrate that slab rollback exerts a first-order control on the spatiotemporal coupling between deformation, basin evolution, and magmatism in slab-top extensional systems.