TMCmod Project: Deciphering the Geodynamic Evolution of the Timok Magmatic Complex in the Serbian Carpathians

The TMCmod project, supported by the Science Fund of the Republic of Serbia (GRANT No. TFC1389-YF/PROJECT No. 7461), investigates the interplay between tectonics, magmatism, sedimentation, and ore-forming processes in the Timok Magmatic Complex (TMC) of the Serbian Carpathians. The TMC represents a segment of the Apuseni–Banat–Timok–Srednogorie (ABTS) volcano-sedimentary belt, formed during Late Cretaceous subduction-related geodynamic processes in SE Europe. Integration of detailed field-based structural and fault-kinematic analysis with zircon U–Pb geochronology of syn-tectonic intrusions indicates that the TMC represents a highly asymmetric extensional basin formed during Neotethyan slab rollback. Basin evolution was controlled by E–W to NE–SW extension, with the earliest Albian–Cenomanian stage characterized by border-fault-accommodated subsidence and syn-rift sedimentation. At ~88–87 Ma, deformation progressively migrated into the basin interior and localized along a major intra-basin normal-fault corridor in its eastern part. This structure focused syn-tectonic calc-alkaline magmatism, dyke emplacement, hydrothermal activity, and ore formation. Between ~88 and 81 Ma, deformation and magmatism propagated laterally along strike, reflecting progressive growth of the fault system during syn-rift basin evolution. The results demonstrate that the TMC constitutes a segment of the ABTS belt in which rollback-driven extension, calc-alkaline magmatism, and ore-forming hydrothermal processes became directly coupled through fault-controlled magmatic and hydrothermal activity. To further constrain the geodynamic significance of this tectono-magmatic coupling, Lu–Hf isotope analyses were performed on zircon populations previously dated by U–Pb geochronology. These analyses provide additional constraints on magma sources, mantle versus crustal contributions, and the temporal evolution of magma generation processes associated with rollback-related extension. The post-rift stage is characterized by Campanian–Maastrichtian shallow-marine carbonate sedimentation represented by rudist-bearing limestones and associated shallow-water fossil assemblages. Biostratigraphic, sedimentological, and microfacies analyses constrain the temporal transition from the late syn-rift stage of extension to the onset of basin inversion and provide insights into depositional environments during post-rift evolution. The subsequent evolutionary stage corresponds to the latest Cretaceous–earliest Paleogene basin inversion, expressed by a progressive transition from contractional to transpressional deformation associated with closure of the Ceahlău–Severin Ocean and the onset of Carpathian collision. During this stage, shortening became localized along inherited extensional basin structures, resulting in structural inversion of the TMC basin. The youngest deformational phase reflects Oligocene–Middle Miocene post-orogenic strain partitioning and strike-slip faulting related to oroclinal bending of the Carpatho-Balkanides, which controlled segmentation and sedimentary reorganization of both the TMC basin and the broader ABTS belt. The next phase of the TMCmod project will involve high-resolution numerical modelling of interactions among tectonic, magmatic, and ore-forming processes to test and refine the multidisciplinary result obtained within the project.