The study area is situated in the Low Tatras Mountains – a typical example of the Tatric crystalline basement of the Western Carpathians in Slovakia. The geological exploration took place between 1980 and 1991 and is considered one of the most complex and detailed tasks in Slovak ore-body exploration. As a result, a 2 km2 mineral deposit was delineated and studied for scheelite-gold ore bodies. The deposit was considered economically marginal and non-economic for further search and mining under prevailing market conditions. However, in the field of geology, it represents an interesting and unique locality of tectonic development in the Low Tatras Mountains. The deposit is located in a highly fragmented area with a complex fault system, as there are 4 rock complexes on a relatively small area.
The complexity of the geological structure and the inconsistency of interpretations regarding the areaˈs development are common topics of discussion among experts. The use of modern geoinformatics technologies, which can process data from geological surveys, can help interpret the positions of rock complexes and bring new knowledge to discussions about the development of the area. The asymmetric nature of megaanticlines of crystalline basement is also shown here - the southern slopes consist of metamorphites, while the northern ones feature granitoids.
The result of the geological survey is a final report that contains detailed data of 220 exploration drillholes, forming a relatively dense network up to a depth of 650 m. These are essential for digitalization and spatial visualization in the GIS environment. For a long time, such visualizations were only obtainable using specialized software platforms, which are typically financially demanding items. Nowadays, freely available GIS technologies are capable of processing complex data to create simple visualizations of geological surveys. Probably the best example is open-source software QGIS – this popular platform with many available plug-ins focused on all kinds of geospatial themes. Geoscience is a dedicated plug-in for processing the data of a geological survey. Based on the coordinates of initial drillhole points, inclinometry, and lithological content of drillholes, the plug-in can create 3D line layers in a GIS environment that represent their real spatial extent.
196 underground and 24 surface wells were visualized, with a minimum length of 15.5 m (underground well No. 12) and a maximum length of 650 m (surface well No. 99). The boreholesˈ spatial paths, direction, and mutual orientations cover a large part of the deposit, as well as the area to the north-east.
Thanks to the number of work modules with a wide range of focus and their gradual development, QGIS will potentially represent a suitable alternative to commercial geological 3D modeling software in the near future. By checking the input data and possibly modifying it based on a simple initial visualization, the level of the database that can be worked with at a professional level is reached.
This abstract was supported by grant APVV-22-0092.
How to cite: Šuvada, T., Masný, M., Kopáčik, R., and Spišiak, J.: Digitalization and Spatial Visualization of Exploration Drillhole Data Using the Open-Source GIS Platform QGIS: A Case Study of the Jasenie-Kyslá W-Au Ore Deposit, Central Slovakia, Western Carpathians, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-44, https://doi.org/10.5194/egusphere-alpshop2026-44, 2026.
This study presents a basin-scale tectono-magmatic model for the Late Cretaceous evolution of the Timok Magmatic Complex (TMC) basin in the Serbian Carpathians, a segment of the Apuseni–Banat–Timok–Srednogorie (ABTS) volcano-sedimentary belt in SE Europe. Integration of structural and kinematic analyses with zircon U–Pb geochronology of syn-tectonic intrusions indicates that the TMC basin formed as a strongly asymmetric basin under E–W to NE–SW extension driven by rollback of the Neotethys slab. Early basin development was controlled by border-fault-related subsidence and sedimentation. At ~88–87 Ma, deformation migrated into the basin interior and localized along a major intra-basin normal fault corridor in the eastern part of the basin, focusing 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. After ~81 Ma, extensional deformation waned, while magmatism migrated westward and became increasingly decoupled from faulting. These results demonstrate that slab rollback exerted a first-order control on the spatiotemporal coupling between deformation, basin evolution, and magmatism in slab-top extensional systems.
Keywords: Timok Magmatic Complex, Serbian Carpathians, fault kinematics, zircon U–Pb geochronology, tectono-magmatic evolution, Neotethys subduction.
How to cite: Kostić, B., Randjelović, N., Stojadinović, U., Maleš, M., Grujovski-Stanisavljević, M., and Srećković-Batoćanin, D.: Tectonic control of Late Cretaceous calc-alkaline magmatism in the Timok Magmatic Complex (Serbian Carpathians): Insights from U–Pb zircon geochronology and fault kinematics, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-5, https://doi.org/10.5194/egusphere-alpshop2026-5, 2026.
The Bukulja Mts. and its surroundings in the Internal Dinarides of central Serbia, provide an important record of post-collisional tectonic and thermal events during Oligocene-Miocene time. This is expressed by intense extensional deformation characterized by core complex geometry and the presence of granitoid intrusions of different ages and composition. The Oligocene I-type Brajkovac intrusion records an earlier stage of post-collisional magmatism, probably related to detachment of the Neotethyan slab beneath the Dinarides. In contrast, the Miocene S-type Bukulja granite reflects a later extensional stage that caused lithospheric thinning and crustal melting likely associated with the opening of the Pannonian back-arc basin. To improve the understanding of thermal history of the Bukulja-Brajkovac area and its relationship with extensional deformation, we performed fission-track analysis of apatite grains from magmatic and meta-sedimentary rocks, combined with kinematic analysis of the observed structures.
Such an approach enables us to define the main phases of exhumation and associated deformation, and to examine differences in thermal histories of the Brajkovac and Bukulja intrusions. The obtained results improve the understanding of the Cenozoic geodynamic evolution of the northern Internal Dinarides and the overall transition from collisional to post-collisional processes of orogens.
Keywords: apatite fission-track analysis, post-collisional extension, Internal Dinarides, core complex, Cenozoic exhumation
How to cite: Radosavljevic, J., Stojadinovic, U., Trivic, B., Randjelovic, N., and Mladenovic, A.: Low-temperature thermochronology of the Bukulja-Brajkovac area (central Serbia): new constraints on the Cenozoic exhumation of the Internal Dinarides, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-6, https://doi.org/10.5194/egusphere-alpshop2026-6, 2026.
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.
How to cite: Stojadinovic, U., Randjelovic, N., Kostić, B., Djerić, N., Maleš, M., Srećković-Batoćanin, D., Toljić, M., Trivić, B., Đorđević, B., and Grujovski-Stanisavljević, M.: TMCmod Project: Deciphering the Geodynamic Evolution of the Timok Magmatic Complex in the Serbian Carpathians , 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-7, https://doi.org/10.5194/egusphere-alpshop2026-7, 2026.
Palaeogene syn-collisional basins of the Sava Suture Zone (SSZ) record the sedimentary response to the continental collision between the Adria plate and the Tisza Mega-Unit. This study presents a preliminary investigation of polymict conglomerates from selected localities from Zrinska Gora and Požeška Gora mountains, combining petrography, whole-rock geochemistry and zircon geochronology to constrain sediment provenance and basin evolution.
Petrographic analyses reveal a diverse assemblage of pebble lithotypes, including granitoid, volcanic, and metamorphic clasts, reflecting multiple source rocks. Petrographic characteristics provide initial indications that certain pebble lithologies may correlate with nearby inselberg sources, but these interpretations remain tentative and must be further evaluated through whole-rock geochemistry and constrained by zircon U–Pb geochronology. The presence of granitoids and volcanics indicates a significant contribution from magmatic units of the SSZ, while metamorphic pebbles suggest additional input from the pre-Eocene metamorphic basement.
Preliminary whole-rock geochemical data from selected pebbles indicate A-type granite affinities and alkaline magmatic signatures, consistent with previously documented SSZ magmatism. Ongoing geochronological analyses of zircons separated from representative pebbles aim to provide more robust age constraints on source lithologies. These data will enable direct correlation between sedimentary components and their parental magmatic and metamorphic units, offering critical temporal constraints on sediment supply and tectono-magmatic evolution.
The integration of petrographic, geochemical, and geochronological datasets provides new insights into sediment routing systems and provenance evolution in Palaeogene syn-collisional settings of the western branch of the SSZ. This work contributes to a broader understanding of the interplay between subduction, collision, and basin development within the Alpine-Mediterranean orogenic system. The presented work is supported by the Croatian Science Foundation Project SECret (HRZZ IPS-2023-02-2683).
How to cite: Plavac, M., Petrinec, Z., Šuica, S., Olić Peco, I., Klötzli, U., and Lužar-Oberiter, B.: Integrating Petrography and Geochemistry: New Insights Into Palaeogene Polymict Conglomerates From Zrinska Gora And Požeška Gora Mountains (Sava Zone, Croatia), 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-28, https://doi.org/10.5194/egusphere-alpshop2026-28, 2026.
The South Balkan region represents a transition zone between oblique continental collision in the Dinarides to the north and rollback subduction of oceanic lithosphere in the Aegean to the south. This tectonic transition has resulted in complex crustal deformation patterns and the formation of numerous sedimentary basins during the Neogene, some still actively extending today. Slab tearing or break-off of the lower plate at depth, as well as interactions with the North Anatolian Fault Zone, have been suggested as possible drivers of the observed crustal deformation. However, the spatiotemporal evolution of deformation and its relation to present-day seismicity and relief of the region remain poorly constrained. We aim to quantitatively constrain the deformation and paleogeographic evolution of the South Balkan region, in order to assess the relative contributions of slab dynamics and activity along the North Anatolian Fault Zone to upper-plate deformation.
We define the study area between two major tectonic boundaries. In northern Albania and Kosovo, the Shkoder-Peja Fault System (SPFS) marks the boundary between the Dinarides orogen to the north and the Albanide-Hellenide orogen to the south, accommodating a roughly 30° clockwise oroclinal bend related to south-westward retreat of the Hellenic subduction zone. In northern Greece, the Kefalonia Transfer Fault (KTF) separates the Adriatic plate to the north from the Ionian and eastern Mediterranean oceanic lithosphere to the south. While the region south of the KTF and the external part of the Dinarides-Hellenides have been extensively studied, the internal part of the orogen between the KTF and the SPFS has traditionally received less attention.
We conducted an initial field campaign in March 2026, focussing on the sedimentary record of the basins and on evidence of faulting related to basin formation in eastern Albania, North Macedonia and Kosovo. Furthermore, we carried out sampling for cosmogenic nuclides and thermochronology, aiming to better constrain the temporal evolution of erosion rates and fault activity. Here, we present preliminary results, such as a compilation of geophysical, geomorphological, and geological data, including active faults, seismicity, relief, thickness of basin infill, and age of basin formation. We aim to use this integrated approach to study the relationship between present-day seismicity, relief formation and tectonic activity, as well as to quantify basin subsidence and reconstruct the paleogeographic evolution of the region.
How to cite: Wagenaar, S., le Breton, E., Roullier, D., Delgado, V., Robin, C., Gemignani, L., Muceku, B., Najdovska, J., Drogreska, K., and van der Beek, P.: Evolution of Neogene basins and fault systems in the Southern Balkans, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-35, https://doi.org/10.5194/egusphere-alpshop2026-35, 2026.
The External Dinarides fold-and-thrust belt formed during the Middle Eocene–Oligocene as deformation propagated southwestward from the Internal Dinarides toward the Adriatic foreland during the Adria–Europe convergence and collision. Although the overall architecture of the External Dinarides is well established, the Gorski Kotar region remains one of its least understood segments. Here, the original contractional architecture has been extensively modified by pre- and post-orogenic extension and transpression, obscuring primary syn-orogenic thrust relationships and complicating the reconstruction of its tectonic evolution. We present the first results of comprehensive structural mapping, kinematic analyses, geological cross-sections, and Raman spectroscopy of carbonaceous material (RSCM) thermometry, integrated into an annotated geological map and short cross-sections to reconstruct the structural evolution of the region.
The study area exposes nearly complete Upper Triassic to Upper Cretaceous shallow-marine carbonate successions unconformably overlying Permian siliciclastic prodelta turbidites, incorporated in several thrust sheets. RSCM analyses of the Permian siliciclastics record maximum burial temperatures of approximately 180–230 °C, corresponding to burial depths of about 6–8 km, which exceeds the thickness of the preserved sedimentary cover (approximately 5 km), implying an additional component of tectonic loading beneath thrust sheets.
Structural mapping reveals two W- to SW-dipping thrust-related homoclines, bounded by the dextral Idrija Fault to the north and the Delnice Fault to the southeast, which separate the Gorski Kotar and Kvarner structural domains. Whereas deformation in the Kvarner domain primarily involves Cretaceous and Paleogene strata, the Gorski Kotar domain incorporates Permian to Upper Jurassic rocks into an E- to NE-vergent back-thrust system segmented by the NE-striking Delnice Fault. The juxtaposition of contrasting Jurassic facies across the Delnice Fault suggests that it represents an inherited pre-orogenic, extensional structure that influenced the development of the syn-orogenic contractional architecture.
Subsequently, the Dinaridic syn-orogenic thrust system was overprinted by polyphase deformation. High-angle normal faults related to E- to NE-directed post-orogenic extension dissect the thrust sheets and locally expose footwall units, resulting in the poor preservation of primary thrust contacts and fault kinematic data. In the northeastern part of the study area, younger (late Neogene?) SW-vergent thrusts locally overprint the earlier back-thrust system, producing apparent stratigraphic inversions by the emplacement of younger footwall units above older hanging wall units.
These results demonstrate that the tectonic evolution of the Gorski Kotar region reflects the superposition of pre-orogenic extension, syn-orogenic (back-) thrusting, post-orogenic extension, and younger (Neogene?) contractional overprint. The resulting structural framework provides new constraints on the tectonic evolution of the northern External Dinarides and the role of inherited structures controlling subsequence deformations.
Presented research was conducted in the scope of the internal research project GeoDRIFT at the Croatian Geological Survey, and Next Generation NPOO project GEO-RIZ, funded by the National Recovery and Resilience Plan 2021–2026 of the European Union – NextGenerationEU, and monitored by the Ministry of Science and Education of the Republic of Croatia.
How to cite: Vukovski, M., Balling, P., and Tomljenović, B.: Structural framework and polyphase kinematic evolution of the Gorski Kotar region, External Dinarides, Croatia – A map View, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-36, https://doi.org/10.5194/egusphere-alpshop2026-36, 2026.
This integrated paleomagnetic and mineralogical study investigates the Late Jurassic ophiolites of the Western Vardar Zone in Serbia. The Western Vardar ophiolitic unit constitutes a prominent 100–150 km wide belt of obducted ophiolites representing the former Vardar-Meliata Ocean, a northwestern branch of the Neotethys.
From the Western Vardar ophiolite belt, oriented cores were collected from 18 localities representing different lithologies, including serpentinized peridotites, diabases, gabbros, amphibolites, and eclogites.
The laboratory analysis included standard demagnetization processes, as well as the investigation of the magnetic properties and mineralogical composition of the sampled rocks. In serpentinized peridotites, possible correlations between the degree of serpentinization and the magnetic susceptibility, as well as the natural remanent magnetization (NRM) were examined.
Magnetic mineralogical analyses suggest that magnetite is the dominant ferromagnetic mineral in the studied rocks, with minor to intermediate amounts of ferritchromite in serpentinites, and titanomagnetite in diabases and some serpentinites. The grain size of the magnetite varies between the pseudo-single domain and multidomain ranges. In the serpentinized peridotites (serpentinization degree: 40–90%), magnetite formed during the serpentinization, and can preserve the magnetization acquired at the time of this process.
Well-defined paleomagnetic directions were obtained for 12 localities and can be divided into two groups. In one group, the directions cluster close to the present-day magnetic field, suggesting a very recent remagnetization. The other group shows an approximately 30° clockwise rotation, which is consistent with previously observed Oligocene–Miocene results from the wider area. The similar directions obtained on both serpentinites and diabases, together with the derived paleolatitude from the overall mean direction from the ophiolites, raise the possibility of remagnetization during the late Paleogene–Neogene.
This study is supported by the bilateral project between Serbia and Hungary with reference numbers of 2023-1.2.4-TÉT-2023-00088 and 001908878 2025 13440 003 000 000 001 02 003.
How to cite: Velki, M., Márton, E., Prelević, D., Imre, G., Stanković, N., and Cvetkov, V.: Paleomagnetism of the Western Vardar ophiolitic unit: indication for Oligocene–Miocene remagnetization, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-59, https://doi.org/10.5194/egusphere-alpshop2026-59, 2026.
The Dinarides fold-and-thrust belt formed due to the convergence between the Adriatic and Eurasian plates, culminating in continent–continent collision during the latest Cretaceous. Deformation first affected the internal Dinarides and subsequently propagated southwestward towards the External Dinarides during Eocene–Oligocene. Throughout most of the External Dinarides, up to 8 km thick carbonate-platform successions of predominantly Mesozoic age are deformed into NW–SE-striking, SW-vergent thrust sheets. In contrast, the Gorski Kotar region (NW Croatia) is characterized by a distinct change in the orientation of the fold-and-thrust belt, with predominantly N–S-striking structures and localized E- to NE-vergent thrusting. Field observations and cross-sections suggest that this structural anomaly is inherited from Early Jurassic E–W-directed extension, which caused a syn-rift succession up to ~2.7 km thick, approximately five times thicker than in adjacent regions.
To study these thickness variations and structural architecture in more detail, we constructed three geological cross-sections based on field observations, dip data, fault kinematic data, and geological maps. These cross-sections represent the deformed state of the region and were used in 2D kinematic forward models to simulate deformation over time.
The study area hosts extensive exposures of Permian siliciclastics, bounded to the west and to the south by thrust-related homoclines, which we interpret as relict back thrust ramps. To the north, the active dextral Idrija Fault bounds the Permian rocks. The Permian siliciclastics consistently occupy the structurally highest position and form the basal unit of a regionally continuous thrust sheet emplaced during Eocene–Oligocene shortening on top of the Mesozoic carbonate succession. The present-day distribution of this thrust sheet has been strongly modified and fragmented by subsequent post-orogenic extension and transpression.
Our results indicate that the present-day structural architecture was largely controlled by Early Jurassic extension accommodated by WSW-dipping normal faults. During subsequent Eocene–Oligocene shortening, this inherited rift architecture promoted the development of a top-to-the-NE/E-directed passive roof thrust sheet above a structurally complex triangle structure. Field observations and forward models further show that this thrust sheet was not emplaced atop a single stratigraphic horizon but instead overrode a structurally complex footwall that had already experienced folding, thrusting, and erosion prior to emplacement.
How to cite: Balling, P., Vukowski, M., Tomljenović, B., and Ustaszewski, K.: Structural framework and polyphase kinematic evolution of the Gorski Kotar region, External Dinarides, Croatia – A cross-section view, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-64, https://doi.org/10.5194/egusphere-alpshop2026-64, 2026.
The Sava-Vardar Zone in the Balkans represents a major Tethyan suture zone whose tectonic history is instrumental to paleogeographic reconstructions of the Adria-Europe collision in the region. In this study we apply coupled detrital zircon U-Pb geochronology and Lu-Hf isotope geochemistry to constrain the provenance and pathways of Upper Cretaceous syn-tectonic sedimentary sequences. By fingerprinting the crystalline basements and matching their unique isotopic signatures to the overlying clastic formations, we evaluate the spatial proximity of the margins during the Cretaceous age.
Crystalline basement characterization reveals contrasting geochronological fingerprints for each continental margin. The Adriatic margin (Dinarides) is characterized by a prominent Permotriassic signal(s) alongside Cadomian and Variscan populations. Importantly, Lu-Hf data from these Adriatic Triassic zircons reveal strongly positive eHf values, reflecting significant juvenile mantle input during regional rifting. In contrast, the European margin basement blocks (Serbian-Macedonian Massif and Carpatho-Balkanides) are dominated by Ordovician (Cenerian) and Carboniferous (Variscan) zircons showing respective crustal and juvenile eHf signatures, completely lacking the Triassic signal.
Provenance study of the Upper Cretaceous flysch and Lower Cretaceous paraflysch sequences yield critical paleogeographic insights. Clastites from the Upper Cretaceous Sava Zone (Adria margin) and the Lower Cretaceous paraflysch sequences sitting structurally on the European margin (e.g., Kragujevac, Slavkovica, and Kadina Luka) exhibit overlapping detrital zircon age spectra and eHf isotopic arrays. Both sedimentary domains contain the diagnostic Adria-derived Permo-Triassic population(s) carrying the distinctive juvenile eHf mantle signature. On the other hand, Cretaceous sequences located farther east of the paraflysch belt (such as the Bor Basin) completely lack this juvenile Triassic signature, confirming an unmixed Europe-derived sediment supply.
The presence of the distinct Adria-derived Permo-Triassic population and its coupled juvenile eHf signature within the paraflysch sequences on the European margin demonstrates that sediment routing from the Adria side into the European margin basin was already well established by the Early Cretaceous. This cross-suture sediment provenance indicates tight spatial proximity between Adria and Europe. Ultimately, these combined U-Pb and Lu-Hf data exclude the existence of a wide (>300 km) Sava Ocean already during the Early Cretaceous, pointing instead to a narrow oceanic conduit or an advanced stage of continental collision.
How to cite: Prelević, D., Sokol, K., Xie, J.-C., Mladenović, A., Cvetković, V., and Gajić, V.: Detrital zircon U-Pb-Hf constraints on the Upper Cretaceous evolution of the Sava-Vardar Zone: implications for the waning stage of the Neotethyan Ocean, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-65, https://doi.org/10.5194/egusphere-alpshop2026-65, 2026.
Modern interpretations of the geological evolution of the Balkan terranes frequently correlate the Pelagonian unit with the Drina-Ivanjica and East Bosnian-Durmitor units, considering them as the fragments of the Adriatic plate margin. The Pelagonian massif is approximately 420 km long and about 60 km wide, extending in a NNW-SSE direction, representing a part of the central Hellenides. It is located between the Vardar zone and the Dinaride (West Vardar) ophiolite belts, across the territories of North Macedonia and Greece (Florina terrane).
Here, we document Lower Cretaceous magmatic zircon crystallization ages in this sector of the basement (Boev et al., 2024). In the investigated localities, the pegmatites are structurally and genetically linked to distinct plutonic suites: syenites in the village of Alinci and two-mica granitoids in the village of Čanište. Geochemical and U-Pb geochronological results reveal that this magmatic episode is split into two highly distinct temporal and compositional groups. The Čanište occurrences yield an older, syn-collisional S-type signature at ca. 130 Ma. Conversely, the Alinci pegmatites yield a significantly younger age of ca. 105 Ma, characterized by an alkaline A-type chemistry marked by the presence of alkaline amphibole (arfvedsonite).
These geochronological data have potential to provide critical regional geodynamic constraints. Within the adjacent Rhodopian section of the Balkans, active subduction-related magmatism and high-pressure metamorphism peaked during the Middle Jurassic to earliest Cretaceous between ca. 150–130 Ma, recording the early amalgamation of internal terranes (Kounov & Gerdjikov, 2024). Our new data may indicate that the eastern Pelagonides followed a distinct, diachronous continuation of this mobile boundary along the European margin, rather than remaining a passive domain across a wide, open Vardar Ocean at 120 Ma as depicted by widely accepted paleogeographic models (Gallhofer et al., 2015, van Hinsbergen et al., 2020). The ca. 130 Ma to 105 Ma magmatic pairing broadly fits into this active margin migration tectonics: the ca. 130 Ma S-type melting aligns with the onset of external Pelagonian collisional anatexis between ca. 130–110 Ma, reported also in the Greek Pelagonian zone at 117 ± 8 Ma (Schenker et al., 2014). The younger, ca. 105 Ma post-collisional A-type signature records subsequent crustal thinning and extension, being a late-stage event completely absent within the older Rhodopian structural architecture.
Boev, I., Ivanova, T. & Lepitkova, S. (2024). Geologica Macedonica 38, 97-103.
Gallhofer, D., Quadt, A. v., Peytcheva, I., Schmid, S. M. & Heinrich, C. A. (2015). Tectonics 34, 1813-1836.
Kounov, A. & Gerdjikov, I. (2024). Geologica Balcanica 53, 29-85.
Schenker, F. L., Burg, J.-P., Kostopoulos, D., Moulas, E., Larionov, A. & von Quadt, A. (2014). Tectonics 33, 1552-1576.
van Hinsbergen, D. J. J., Torsvik, T. H., Schmid, S. M., Maţenco, L. C., Maffione, M., Vissers, R. L. M., Gürer, D. & Spakman, W. (2020). Gondwana Research 81, 79-229.
How to cite: Prelević, D., Boev, I., Boev, B., Sokol, K., and Mladenović, A.: Geochronological and geochemical characteristics of zircon from Lower Cretaceous pegmatites of the Pelagonian Unit, N. Macedonia, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-66, https://doi.org/10.5194/egusphere-alpshop2026-66, 2026.
Wider Zrinska Gora area is located along the SW margin of the Pannonian Basin, within a Sava Suture Zone – a collision zone between the Tisza unit (European Plate) and the Internal Dinarides (Adria plate). Here, existing structures has been strongly affected by polyphase tectonics, characterized by repeated reactivations and tectonic inversions throughout the Mesozoic and Cenozoic in response to variable regional stresses and interactions between the European and African plates. This study focuses on constraining exhumation phases of the tectonostratigraphic units exposed in the Zrinska Gora area, westernmost SSZ area. The study area comprises four tectonostratigraphic units: the Palaeozoic–Triassic Pre-Karst Unit, the Jurassic Ophiolite Unit, the Upper Cretaceous Sava Zone Unit, and the Palaeogene Foreland Unit. Extensive field observations combined with vitrinite data suggests that the wider Zrinska Gora area generally experienced a low-temperature thermal overprint, sufficient to reset the apatite (U–Th)/He system. Vitrinite reflectance values indicate maximum post-depositional temperatures ranging from 120 to 150 °C (1.07 to 1.46 %Ro) for the Palaeogene foreland Unit, and 120 to 130 °C (0.92 %Ro) for the Jurassic Ophiolite Unit. In contrast, the Palaeozoic formations of Pre-Karst Unit exhibit a significantly higher thermal overprint, with maximum post-depositional temperatures estimated between 250 and 270 °C (4.64–5.94 %Ro), sufficient to fully reset the zircon (U–Th)/He system. Integration of the new zircon and apatite (U–Th)/He ages with vitrinite reflectance data suggests four tectonic phases in the thermal and structural evolution of the study area: i) Late Cretaceous thermal overprint of Sava Zone Unit deposits; ii) Palaeocene to early Eocene thrust propagation, nappe stacking, and partial exhumation caused by tectonic erosion; iii) post-collisional exhumation in the Late Eocene–Oligocene associated with Adria plate rollback; and iv) final Miocene extensional exhumation linked to reactivation of older thrusts due to lateral extrusion of the ALCAPA block and opening of the Pannonian Basin.
The presented work is supported by the Croatian Science Foundation project SECret (HRZZ IPS-2023-02-2683).
How to cite: Olić Peco, I., Lužar-Oberiter, B., Matoš, B., and Dunkl, I.: Apatite and zircon (U-Th)/He age constraints on exhumation phases of the westernmost Sava Suture Zone (Zrinska Gora, Croatia-Bosnia and Herzegovina boundary) , 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-73, https://doi.org/10.5194/egusphere-alpshop2026-73, 2026.
For decades, the geotectonic models of the Balkan Peninsula presumed a unified Late Jurassic termination for the Neotethyan oceanic domain traditionally called Vardar Ocean. However, the identification of Late Cretaceous ages of a magmatic suite within the Kozara Mts. in N. Bosnia and Herzegovina, triggered a major paradigm shift, introducing the concept of Late Cretaceous ophiolites to the region. Consequently, researchers began reinterpreting these formations as evidence of a still-open oceanic realm called the Sava Ocean, extending the regional subduction-collision timeline to the Late Cretaceous-Paleogene. The Kozara suite consists of gabbros, dolerites, pillow basalts, and rhyolites. Previously, published U-Pb zircon ages are 81.4 Ma for dolerites and 81.6 Ma for rhyolites. In this contribution, we re-investigate this critical locality, using advanced isotopic techniques combined with new geochronological constraints.
New U-Pb analyses of zircons from rhyolites reveal inherited Permian-Triassic and Variscan zircon populations, providing direct evidence for continental crustal involvement in the evolution of the felsic magmas. Notably, inherited zircon populations have also been reported from Late Cretaceous magmatic rocks of the Slavonija–Srijem Depression and the Slavonian Mountains, suggesting that this was a regional characteristic of Late Cretaceous Sava Zone magmatism.
Kozara basalts display LREE-enriched REE patterns, enriched MORB affinities on the Nb/Yb-TiO2/Yb discrimination diagram, and no significant HFSE depletion on primitive mantle-normalized multi-element diagrams, indicating derivation from an enriched asthenospheric mantle source. Whole-rock Sr-Nd-Pb-Hf isotope signatures for basalts show 87Sr/86Sr = 0.704934-0.707886, 143Nd/144Nd = 0.512882-0.512952, 206Pb/204Pb = 18.92-19.28, 207Pb/204Pb = 15.63-15.67, 208Pb/204Pb = 38.76-39.10, and 176Hf/177Hf = 0.282973-0.283029, whereas the rhyolites exhibit distinct isotopic ratios with 87Sr/86S = 0.706232-0.706462, 143Nd/144Nd = 0.512666-0.512923, 206Pb/204Pb = 19.10-19.03, 207Pb/204Pb = 15.66-15.68, 208Pb/204Pb = 38.93-39.01, and 176Hf/177Hf = 0.282871-0.282893. The rhyolite isotopic arrays are consistent with the involvement of continental crust in their petrogenesis, as also independently inferred from the zircon record. Collectively, these data argue against a purely oceanic origin and instead support the evolution of the Kozara magmatism within an intracontinental setting.
How to cite: Sokol, K., Prelević, D., Mladenović, A., Stracke, A., Gerdes, J., Milošević, A., and Cvetković, V.: Magmatism of Kozara Mts. (N. Bosnia and Herzegovina) revisited: Zircon U-Pb geochronology and Sr-Nd-Pb-Hf isotope geochemistry, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-75, https://doi.org/10.5194/egusphere-alpshop2026-75, 2026.
Cretaceous-Paleogene foreland basins in the Dinarides formed as a consequence of convergence between Adriatic and European plate. These basins were filled by detritus composed of variable amount of carbonate and siliciclastic material, providing record of various units exposed during the initial stages of orogenesis. This study presents detrital zircon geochronology and garnet major-element geochemistry of sandstones from these basins, sampled from different stratigraphic levels from northwestern Croatia to Montenegro, covering almost the entire length of the Dinarides. Preliminary data point to a substantial difference between Lower Cretaceous and Upper Cretaceous-Paleocene sandstones, especially regarding detrital zircon age spectra. The most important dissimilarity is noticeable Permo-Triassic population in the Lower Cretaceous sandstones, completely absent or less pronounced in the Upper Cretaceous and Paleocene ones. The Upper Cretaceous and Paleocene sandstones display variability regarding proportion of Variscan and Cenerian, as well as Precambrian zircon populations. Composition of garnets points to derivation from low to medium grade metamorphic rocks. These new data provide basis for regional interpretation of Cretaceous-Paleogene foreland basins in the Dinarides, and insight into the temporal and spatial diversity of sediment sources during the initial stages of orogeny. The presented work is supported by the Croatian Science Foundation project SECret (HRZZ IPS-2023-02-2683).
How to cite: Šuica, S., Lužar-Oberiter, B., Zeh, A., Schönig, J., Olić Peco, I., Aščić, Š., Petrinjak, K., Banak, A., Bjelogrlić, M., Ćorić, S., and Plavac, M.: Detrital zircon geochronology and garnet geochemistry of sandstones from Cretaceous-Paleogene foreland basins in the Dinarides, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-80, https://doi.org/10.5194/egusphere-alpshop2026-80, 2026.
We present new constraints on post-collisional magmatism in the Internal Dinarides based on a study of the monzogranite intrusion exposed along the southwestern flank of the Kosmaj Mts. in central Serbia. The studied rocks are calc-alkaline granitoids composed predominantly of K-feldspar, plagioclase, quartz, biotite, and amphibole. Amphibole–plagioclase thermobarometry yields crystallization temperatures of 774–831 °C and pressures of ~1.6–2.6 kbar, indicating emplacement at shallow upper-crustal levels. Zircon U–Pb analyses define a concordant age of 24.92 ± 0.31 Ma, constraining emplacement to the latest Oligocene. Zircon Lu–Hf isotopic compositions (εHf(t) = −1.2 to +7.0) indicate a dominantly juvenile magma source with limited crustal contribution. The Kosmaj monzogranite is assigned to the Oligocene I-type granitoid suite, interpreted as the product of Neotethyan slab break-off beneath the Dinarides, which triggered asthenospheric upwelling, enhanced heat flux, and generation of mantle-derived melts variably modified by crustal assimilation.
How to cite: Ćirić, N., Kostić, B., Srećković-Batoćanin, D., Randjelović, N., Maleš, M., Maletić, M., and Stojadinović, U.: Age and origin of monzogranites from the Kosmaj Mts. (central Serbia): new constraints on post-collisional magmatism in the Internal Dinarides, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-4, https://doi.org/10.5194/egusphere-alpshop2026-4, 2026.
The Western Carpathians represent the northernmost segment of the Alpine–Carpathian orogenic system and are characterized by a complex polyphase Variscan–Alpine evolution. The Internal Western Carpathians preserve remnants of the Triassic–Jurassic Meliata Ocean and record a long history of subduction, nappe emplacement and subsequent tectonic overprinting. One of the best exposures of this evolution occurs in the Bretka village area, where the Meliata Unit is bounded to the south by a prominent ductile-to-brittle shear zone. The Bretka shear zone is characterized by the close association of serpentinites, metabasalts, mylonitized carbonates and pseudotachylite-like rocks. In addition, evaporites, mainly anhydrite, are known from borehole data, suggesting that deformation was probably localized within an evaporitic mélange. The serpentinite body is interpreted as a tectonic block incorporated into this mélange. The most significant feature of the shear zone is the relationship between carbonate mylonites and pseudotachylite-like rocks, documenting the transition from ductile to brittle deformation. Mylonites developed within Anisian Steinalm limestones and display a gradual transition from undeformed limestones to completely mylonitized marbles towards the shear zone. The marbles exhibit alternating calcite- and dolomite-rich layers. Calcite forms a fine-grained recrystallized aggregate, whereas dolomite occurs as elongated and rotated porphyroclasts, indicating deformation temperatures of approximately 250–350 °C. Shear bands and asymmetric folds consistently indicate a top-to-the-north sense of shearing. The mylonites are cross-cut by numerous thin calcite veins oriented nearly perpendicular to the mylonitic foliation. Pseudotachylite-like rocks occur mainly within marble layers adjacent to serpentinite bodies and consist of a fine-grained matrix composed of chlorite, epidote and actinolite containing fragmented clasts of albite, calcite, titanite and relict magmatic pyroxene. The observed structures suggest a three-stage evolution of the shear zone. A progressive deformation in ductile conditions caused mylonitization of limestones. A subsequent seismic event caused brittle fragmentation of marble and local frictional melting at the contact with ultramafic rocks. Subsequent fluid infiltration produced an extensive network of thin calcite veins and altered the pseudotachylite-like material to chlorite-, epidote- and actinolite-bearing assemblages. These observations indicate that the mylonitization developed at temperatures below approximately 350 °C, corresponding to depths of roughly 12–14 km with subsequent brittle deformation in the upper parts of the crust. Although kinematic indicators consistently record mainly north-directed transport, both the shear zone and the surrounding rock complexes currently dip to the north. We therefore suggest that the shear zone originally formed during northward nappe emplacement and was subsequently rotated into its present orientation during later tectonic disintegration of the Meliata Unit.
Acknowledgments. The research was supported by the Slovak Research and Development Agency (APVV-21-0281 and SK-HU-24-0016) and the Slovak scientific grant agency VEGA (VEGA 1/0021/25).
How to cite: Potočný, T., Plašienka, D., and Molčan Matejová, M.: From ductile to brittle shear zone - insights from the complex imbricated structure of the Internal Western Carpathians near Bretka village, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-49, https://doi.org/10.5194/egusphere-alpshop2026-49, 2026.
Our investigation focused on the kinematic analysis and paleostress reconstruction of the brittle structures of the Hronic Unit in the Malé Karpaty Mountains and Strážovské vrchy Mountains. The Hronic nappe system represents the structurally highest tectonic unit in the Late Cretaceous thrust stack of the Central Western Carpathians. Structurally, the Hronic Unit is an internally complex nappe system with numerous partial nappes. It consists mainly of a Permian volcano-sedimentary sequence (Malé Karpaty Mts.) and Triassic carbonate sediments (Strážovské vrchy Mts.).
Based on kinematic analyses of mesoscale faults (slickensides), several brittle deformation stages characterized by distinct properties of the reconstructed stress field were identified. We employed the Win Tensor program to calculate stresses and to separate the faults into homogeneous groups. The relative superposition of individual palaeostress states was derived from field structural relationships. The observed chronology of deformation phases can be divided into five different palaeostress fields. The evolution is characterised by a continuous change in the orientation of the maximum principal stress axis σ1, from W–E through N–S to NE–SW. The kinematic analysis of fault-slip data confirmed predominant strike-slip nature of the fault during the entire deformation history.
The oldest deformation event is characterized by a transpressional tectonic regime, in which the maximum compressional stress axis was oriented W–E. This stage includes dextral strike-slip faults trending NE–SW and sinistral strike-slip faults trending NW–SE at both localities. At the Strážovské vrchy Mts., reverse faults with an approximately N–S orientation were also documented. The second deformation stage, associated with NW–SE-directed compression, represents a direct continuation of the transpressional tectonic regime. Acting compression resulted in the development of W–E-trending dextral strike-slip faults and N–S-trending sinistral strike-slip faults. Reverse faults with NE–SW orientation were documented at the Malé Karpaty Mts. The subsequent third deformation stage includes NW–SE-trending dextral strike-slip faults and NE–SW-trending sinistral strike-slip faults at both localities. At the Malé Karpaty Mts., an additional group of WNW–ESE oriented reverse faults were identified. A transpressional tectonic regime persists during this stage, however, the orientation of the compression differs slightly between the two localities. At the Strážovské vrchy Mts., compression is oriented approximately N–S, whereas at the Malé Karpaty Mts. it is shifted eastward to an NNE–SSW orientation. The fourth deformation event represents the final stage associated with a transpressional tectonic regime. The acting compression was oriented NE–SW. Dextral strike-slip faults are N–S-trending and sinistral strike-slip faults are W–E-trending. NW–SE-oriented reverse faults were documented at both localities. However, at the Strážovské vrchy Mts., two groups of reverse faults with a paired relationship were identified. The youngest deformation event represents a change of tectonic regime from a transpressional to an extensional one. At both localities, extension oriented NNW–SSE and NE–SW was documented. In addition, WNW–ESE-oriented extension was identified at the Strážovské vrchy Mts.
Figure 1: Chronological summary of deformation events in the study areas.
Acknowledgements
This work was supported by the Slovak Research and Development Agency under the contracts APVV-22-0092.
How to cite: Obertová, A., Šimonová, V., and Butek, J.: Kinematic analysis of the Permian and Triassic Formations of the Hronic Unit (Western Carpathians, Slovakia), 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-61, https://doi.org/10.5194/egusphere-alpshop2026-61, 2026.
The Sardinia-Corsica lithospheric block played a key role in the Cenozoic tectonic evolution of the Western Mediterranean, since Miocene drifting from the southern European margin and opening of the Algero-Provençal Basin to the Plio-Quaternary evolution of the Tyrrhenian Basin. Following the structuring of the eastern Sardinian margin, extensional deformation progressively migrated eastward driven by retreat of the Tethyan slab, leading to the formation of the Vavilov Basin during the Pliocene and the Marsili basin during Pleistocene. In Sardinia, Quaternary tectonics has traditionally interpreted has the westernmost expression of this extensional regime, mainly testified by the structuring of the Campidano graben and contemporaneous intra-plate volcanic activity.
Here we present geological, geophysical and geomorphological evidence indicating that tectonic activity in Sardinia persisted throughout the Quaternary and cannot be entirely explained by the evolution of the Tyrrhenian extensional system. The data suggest that an additional geodynamic process has controlled the recent deformation of the island.
The Campidano graben, filled by more than 1 km of Pleistocene-Holocene continental deposits, represents the main Quaternary tectonic structure in Sardinia. Seismic reflection data and field observation document the occurrence of Upper Pleistocene-?Holocene normal faults affecting both the basin fill and the western footwall of the graben. Low-magnitude seismicity is concentrated along the main Cenozoic fault systems, including the Campidano Graben, with hypocentres generally shallower than 10 km. Geothermal springs aligned along these fault zones indicate that they remain permeable and provide pathways for deep fluid circulation. In addition, GNSS measurements reveal vertical crustal motions of few mm per year, despite the limited seismic activity. Recent uplift is also supported by geomorphic evidence, including deep river valleys and widespread relief rejuvenation.
The Upper Pleistocene-Holocene age of the deformation suggests that the observed tectonic activity postdates the main extensional phases that affected the western Tyrrhenian Basin. During the Late Quaternary, active deformation was largely restricted to the Marsili sector, whereas no evidence of active deformation is recognized in the Vavilov Basin, between Sardinia and Marsili. Consequently, the recent tectonic activity in Sardinia is unlikely to be directly related to the present evolution of the Tyrrhenian Basin.
We propose that the observed deformation reflects regional uplift associated with the anomalous lithospheric structure beneath Sardinia, characterized by a relatively thin lithospheric mantle beneath a crust of approximately normal thickness. The origin of this lithospheric thinning remains uncertain but may be related to mantle processes inherited from Tethyan subduction, such as the presence of a stagnant slab and/or small-scale mantle convection, promoting asthenospheric upwelling, thermal erosion of the lithosphere, and long-lived surface uplift.
How to cite: Cocco, F. and Funedda, A.: Quaternary tectonics in Sardinia, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-68, https://doi.org/10.5194/egusphere-alpshop2026-68, 2026.
