The new detailed geological mapping at 1:10.000 scale of >1800 km2 collected in the frame of the Italian Geological Survey Project (CARG project), resulted in a large amount of structural data throughout the Ligurian Alps and the adjacent Ligurian Sea, representing the connection area between the Alpine and Apennine orogenic arches. Field- and remote-sensing-based data highlight the presence of a dense fault-fracture network developed throughout the entire orogenic sector. Detailed structural analysis has been performed in selected sites, through the building of Digital Outcrop Models (DOM) derived from digital photogrammetry and the use of Unmanned Aircraft Vehicles (UAV). The onshore survey is based on the integration of a new set of seismic reflection lines and high-resolution bathymetric data (MBES) with pre-existing available geological and geophysical datasets. The integrated geological mapping and structural analysis can be summarized as follows: i) the entire orogenic sector encompasses a very dense network of relatively small fractures and faults showing complex intersection relationships; ii) from this network, several, previously unreported, km-scale transtensive fault zones emerge; iii) these faults postdate the metamorphic foliation associated with the main thrust-and-fold architecture of the Ligurian Alps; iv) the recognition of earthquake-related soft-sediments deformation structures in Miocene-Pliocene deposits highlights continuous seismicity related to the fault development. The offshore area consists of a continental shelf and the upper slope both intersected by well carved submarine canyons and characterized by a complex fault network. The fault network is characterized by dominant E-W left-lateral and NE-SW right-lateral faults. The entire fault network is interpreted as a complex network of subsidiary, en-échelon Riedel fractures encompassed within a regional sinistral transtensional/transpressional shear zone. The fault network primarily developed in the Oligo-Miocene times, thus during the pre-to-syn Corsica drifting phase. Moreover, both the Ligurian orogen and Ligurian Basin fault systems experienced Miocene to present-day seismicity marked by i) the cyclic occurrence of earthquake-induced soft sediment deformation structures found in the Miocene to Pleistocene sediments and ii) the present-day instrumental recording. In light of the new dataset, we reconsider the role of the local-scale fault network as a direct surface expression of the ongoing bending of the Ligurian Alps, driven by the combination of Adria rotation and the pull of the Apennine subduction.
How to cite: Perozzo, M., Lombardi, S., Stori, L., Menegoni, N., Morelli, D., Crispini, L., Federico, L., Seno, S., and Maino, M.: Analysis of the post-metamorphic fault network of the Ligurian Alps and Ligurian Sea as a key for the understanding the Alps-Apennine transition (CARG project), 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-24, https://doi.org/10.5194/egusphere-alpshop2026-24, 2026.
The Western Carpathians are commonly regarded as the eastern continuation of the Eastern Alps, where closure of the Alpine Tethys culminated in the collision between the European passive margin and the Adria-derived Alpine–Carpathian–Pannonian (ALCAPA) tectonic unit. In contrast to the Eastern Alps, however, the geometry and nature of the Alpine Tethys suture remains poorly constrained in the Western Carpathians. The suture is generally associated with the Pieniny Klippen Belt (PKB), a remarkably narrow yet laterally extensive unit separating the Outer and Central Western Carpathians. Current tectonic models invoke two oceanic domains within the Alpine Tethys—the Magura Ocean to the north and the Vahic Ocean to the south—separated by the continental Czorsztyn Ridge acting as basement for the PKB sediments. Nevertheless, geological and geophysical evidence for this configuration remains equivocal. To provide independent constraints on the tectonic architecture of the Alpine Tethys suture, we investigated the lithospheric structure of the Western Carpathians using passive seismic and potential-field methods.
The passive seismic experiment was conducted along a dense ~N-S transect to acquire data for Receiver Function (RF) analysis. Joint inversion of RFs, P-wave polarization and Rayleigh wave dispersion curves yielded lithospheric-scale seismic velocity models, which were subsequently used for Common Conversion Point (CCP) migration. The resulting images reveal a Moho depth of 30-35 km, interrupted by two major offsets: one beneath the PKB and another beneath the eastern continuation of the Hrubanovo–Diósjenő Fault. Integration of the seismic results into a structural cross-section indicates that the Europe–ALCAPA boundary is best represented by a Pyrenean-style crustal wedge, with the lower crust of ALCAPA acting as an indenter into the European margin.
A prominent southward-dipping to sub-horizontal interface identified within the upper mantle beneath ALCAPA is interpreted as the underthrusted attenuated European passive margin. Importantly, this lithospheric architecture does not provide categorical evidence for the existence of a subducted oceanic slab preceding continental underthrusting. Furthermore, seismic velocities suggest that the underthrusted European crust may terminate around the second Moho offset as mantle-like velocities dominate south of this Moho offset, potentially constraining the extent of continental underthrusting.
Forward gravity modelling based on the seismic cross-section required the incorporation of a low-density body within the upper crust of the European plate to achieve an acceptable fit to the observed gravity field. This feature is consistent with the pronounced Bouguer gravity low associated with the PKB and may reflect the presence of low-density Magura Basin sediments within the underthrusted European margin. The density model was also used to assess the isostatic contribution of the underthrusted crust by comparing scenarios with and without its presence in the upper mantle. The results show that the High Tatras are essentially compensated by the normal crust, whilst the underthrusted lower crust provides significant additional isostatic support leading to higher modelled topography than observed, especially in the Low Tatras.
Acknowledgments: This research was funded by the National Science Centre (Poland), grant no. 2021/43/B/ST10/02312. We also acknowledge the AdriaArray initiative, within which the passive seismic experiment was conducted.
How to cite: Soni, T., Schiffer, C., and Mazur, S.: The Alpine Tethys suture in the Western Carpathians revisited: new constraints from lithospheric-scale geophysical imaging, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-25, https://doi.org/10.5194/egusphere-alpshop2026-25, 2026.
The Matrei Zone represents the Upper Penninic Nappes in the south of the Tauern Window and is positioned between the Lower Penninic Nappes and the Austroalpine Unit in footwall and hanging wall positions respectively. As such, it comprises a heterogeneous association of lithologies derived from the Piemont-Liguria Ocean and its southern continental margin. This continental margin is nowadays represented by the Lower Austroalpine Unit. Various genetic interpretations for the Matrei Zone have been proposed. While its geodynamic setting as accretionary wedge in a subduction zone is widely agreed on, the presence of the Austroalpine lithologies within remains a matter of discussion. Their occurrence in the Matrei Zone is explained either as olistoliths, elements scraped off the upper plate within a tectonic mélange, or as lenses formed by out-of-sequence thrusting. Additionally, the position of the lower boundary of the Matrei Zone to the Lower Penninic Nappes is uncertain as the identification of unambiguous markers is lacking. To unravel the debated tectonic situation of the Matrei Zone, revisited geological mapping of key areas in the contact zone of the Tauern Window and the Austroalpine Unit is needed. Here, we reassess the lithological content, formation, and tectonic meaning of the Matrei Zone based on new detailed geological mapping in the Upper Möll valley (Carinthia, Austria).
Our findings reveal that the basis of the Matrei Zone is marked by a phyllonitization front within the impure marbles of the Lower Penninic Nappes. This becomes apparent by a lithological upward transition from thick impure marbles and massive greenschist to a heterogeneous, diversly coloured succession of siliciclastic and carbonate-clastic metasediments. The Matrei Zone is formed of several lithological associations, which can be followed for several tens of kilometres. We distinguish a lower unit, dominated by dark phyllite intercalated with light-coloured phyllites and carbonates. The upper unit is made of chlorite-rich phyllite, quartz-phyllite and impure quartzite with greenschist. Furthermore, a discontinuous tectonic melange containing additional serpentinite and greenschist within a metasedimentary matrix occurs. All units contain metaradiolarite and metamorphic Aptychus limestone as well as metaconglomerate and large olistholiths. These olistholiths derive from Triassic sequences found in the Austraoalpine Unit. An obvious tectonic contact occurs only at the top of the Matrei Zone towards pristine and coherent Austroalpine Nappes.
Our results are consistent with the interpretation that the Matrei Zone represents an accretionary wedge developed out of the lithosphere and the cover of the Piemont-Liguria Ocean, which was thrusted on top of rocks of the subducting Valais Ocean. The occurrence of Triassic rocks is likely to be the result of gravitative flow from the continental margin within the oceanic basin and not necessarily tectonically induced.
How to cite: Költringer, C., Huet, B., Linner, M., and Lotter, M.: New map, new insights: disentangling the Tauern Window’s Matrei Zone, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-34, https://doi.org/10.5194/egusphere-alpshop2026-34, 2026.
Extensional core complexes commonly develop in regions undergoing post-orogenic extension and lithospheric thinning, where extension exhumes rocks from deeper crustal levels. One such region is the southwestern margin of the Pannonian Basin System, where extension started shortly after the peak orogenic stage of the Dinarides. We present new stratigraphic and thermochronological evidence for the Early Miocene extensional exhumation of the Hrastovička Gora core complex, located at the southwestern margin of the Pannonian Basin System.
The study area exposes a complete geological record related to the Early to Middle Miocene rifting and opening of the Pannonian Basin System, comprising pre-rift, syn-rift and post-rift rock units. Hrastovička Gora Mt. lies in the center of the study area, currently separating the Sava Basin to the NE from the Glina Basin to the SW.
The oldest, Upper Cretaceous to Eocene pre-rift basement units are typically assigned to the so-called Sava Suture Zone of the Dinarides. They comprise Upper Cretaceous granitic and metamorphic rocks, as well as a volcano-sedimentary complex of intercalated spilites and pelagic Scaglia-type limestone, continuously overlain by Paleocene to Eocene, mostly siliciclastic, syn-orogenic flysch-type deposits.
The subsequent Ottnangian to upper Badenian syn-rift deposits consist of siliciclastic conglomerates, sands, marls and limestones recording a gradual transition from alluvial to marine environments. While the surrounding Sava and Glina basins preserve this complete syn-rift succession deposited on top of the basement, the syn-rift units are entirely absent on Hrastovička Gora Mt. itself. There, the post-rift stage begins with a major Late Badenian overstepping transgression, depositing Upper Badenian to upper Pannonian post-rift successions directly above the pre-rift basement. This post-rift thermal subsidence stage forms a complete transgressive–regressive cycle, beginning with basal conglomerates and passing upward into sandstones, limestones, and marls, followed by a gradual shallowing from deep-water marls back to alluvial conglomerates, sands, and clays.
Fission-track and (U–Th)/He dating of zircon and apatite from pre-rift and syn-rift rocks indicates the development of two distinct thermal paths following Late Eocene to Early Oligocene times. Thermochronological data indicate the exhumation of pre-rift basement units of Hrastovička Gora Mt. during Early to Middle Miocene times, whereas basement units of the surrounding Sava and Glina basins had already reached similar crustal levels during the Eocene. The integration of thermochronological and stratigraphic data indicate the existence of an extensional detachment, with Hrastovička Gora representing its exhumed footwall, and the Glina and Sava basins representing a supradetachment basins developed on top of hanging wall units. This detachment probably correlates with detachments previously discovered further southeast along the southwestern margin of the Pannonian Basin System in Prosara, Kozara, Motajica, Cer and Bukulja mountains.
Presented research was conducted in the scope of the internal research project GeoSAVAGE at the Croatian Geological Survey, 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., A. Anczkiewicz, A., Gülyüz, E., Rukavina, D., Kurečić, T., Maslač Soldo, J., and Špelić, M.: Miocene extensional core complex in the SW Pannonian Basin: stratigraphic and thermochronological evidence from Hrastovička Gora Mt., Central Croatia, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-38, https://doi.org/10.5194/egusphere-alpshop2026-38, 2026.
The Transdanubian Range Unit (TRU) forms a thick-skinned nappe within the Eastern Alpine–Western Carpathian orogenic wedge. It is composed of Variscan low-grade metamorphic formations overlain by a Permian to Cenozoic non-metamorphic succession. The northeastern part of the TRU displays several distinctive features: (1) the base of the Permian–Mesozoic succession includes Upper Permian evaporites, which are absent in the central and southwestern parts of the unit; (2) Upper Triassic platform carbonates, deposited along the Neotethyan passive margin, are disrupted by narrow, long-lived intra-platform basins in the northeast of the area; and (3) the Cretaceous fold-and-thrust structures in this region exhibit different orientations and geometries compared to those in the central and southwestern TRU.
Our work is based on field geology, borehole and geophysical data and archive studies. Based on this dataset, the pre-Cenozoic geological map of the study area and three geological cross-sections were constructed, providing new insights into the structural evolution of the region.
According to our model, the Upper Permian evaporites played a key role in the Mesozoic structural evolution of the study area. The narrow Late Triassic basins of the north-eastern TRU developed in the hanging walls of NW–SE-striking normal faults that detached within the Permian evaporites. The development of these faults is interpreted to be related to gravity-driven gliding along the passive margin of the Neotethys Ocean.
We suggest that a south-vergent thin-skinned fold-and-thrust belt developed in the northeastern part of the Transdanubian Range Unit above a relatively shallow detachment level within the Permian evaporites during the Cretaceous (Barremian–Cenomanian). We propose that the local, oblique, NW–SE-striking thrusts formed due to oblique inversion of Triassic normal faults.
The general E–W strike of thrusts and fault-related folds observed in the study area differs from the NE–SW strike typical for the central part of the Transdanubian Range Unit. We interpret this curvature of the compressional structures as a detachment-controlled salient. Based on this model, the thrust sheets underwent larger tectonic transport in the northeastern part of the TRU where Permian evaporites provided a basal detachment, compared to the central and southwestern parts of the unit where such ductile detachment was absent. This interpretation implies vertical axis rotation of the northeastern part of the TRU compared to its central part. The different rotation of the two parts of the unit is supported by Jurassic and Cretaceous paleomagnetic data compiled by Márton et al. (2025), while Late Triassic paleomagnetic data are inconsistent with it, highlighting the need for further investigation. Due to the Late Cretaceous growth of the Western Carpathian orogenic retro-wedge, the thin-skinned fold-and-thrust belt of the study area was re-folded by thick-skinned structures that also deformed the Variscan basement.
How to cite: Héja, G., Budai, T., Palotai, M., and Maros, G.: The role of Upper Permian evaporites in the Mesozoic structural evolution of the northeastern part of the Transdanubian Range Unit , 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-43, https://doi.org/10.5194/egusphere-alpshop2026-43, 2026.
The timing of the Cretaceous Eoalpine event in the Upper Austroalpine Unit (Eastern Alps) is well established. An initial phase of collision and nappe stacking characterized by (W)NW-directed kinematics lasted from c. 135 to 95 Ma, followed by the exhumation of metamorphic units via extrusion between thrusts with W-directed kinematics and large-scale normal faults with (E)SE-directed kinematics from c. 95 to 65 Ma. Although large-scale normal faults along the Austroalpine Detachment System are thoroughly documented in the hanging wall of the Upper Austroalpine, deformation within its footwall remains poorly understood.
This study investigates the chronological framework and kinematic evolution of the footwall within the Austroalpine extrusion wedge in the Lower Tauern region, where out-of-sequence thrusting, ductile shear zones, and mylonites occur at nappe boundaries. The local geology comprises basement complexes and partial cover units of the Schladming-Seckau and Koralpe-Wölz nappe systems, which record overprinting metamorphism and deformation from Variscan, Permian, and Eoalpine events.
A major shear zone, the Walchen Shear Zone (WSZ), is situated at the boundary between the Wölz and Ennstal complexes within the Koralpe-Wölz Nappe System, affecting rocks of both the underlying Wölz and overlying Ennstal complexes. The WSZ can be traced at the surface for ~800 m perpendicular to strike, spanning ~450 m into the Wölz and 350 m into the Ennstal complex. The mylonitic schistosity dips moderately to steeply to the N(NW), whereas the mylonitic stretching lineation is predominantly subhorizontal or shallowly dipping to the W(NW) or E(SE). Strain intensity increases within the Wölz Complex toward its hangingwall, and deformation is most intense within the footwall of the Ennstal Complex. Mylonitic deformation is particularly well preserved within light-colored, mica-rich quartzites of the Ennstal Complex near the Walchen copper deposit. Microstructural analysis reveals dynamic recrystallization of quartz and calcite, with porphyroclasts of garnet, feldspar, and ankerite. This indicates that the shear zone was active under greenschist-facies conditions between 300 and 450 °C. Within this structural framework, kinematic indicators, such as clast geometries, quartz c-axis fabrics, C- and C'-type shear bands in phyllosilicate-rich rocks, consistently record a top-to-the-west sense of shear. This ductile to brittle-ductile shearing reflects a phase of orogen-parallel to orogen-oblique tectonic transport.
For Ar-Ar geochronology, six samples of deformed quartz veins containing coarse-grained white mica, alongside two samples of white mica from a mylonitic impure quartzite, were collected along the shear zone from both complexes. Single crystal total fusion dates ranging between 91 and 94 Ma are interpreted as formation or deformation ages, constraining the timing of this W-directed kinematic event to the Late Cretaceous. Ultimately, these insights from the WSZ refine existing geodynamic models of wedge extrusion, bridging a critical gap in our understanding of lateral mass transport during continental collision that is accommodated during footwall deformation, which decisively influenced the final architecture of the Central Austroalpine region.
How to cite: Iglseder, C., Schneider, D., and Grasemann, B.: Timing and west-directed kinematics in the footwall part of the Upper Austroalpine extruding wedge: Insights from the Lower Tauern region (Austria), 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-52, https://doi.org/10.5194/egusphere-alpshop2026-52, 2026.
During the Mesozoic and Paleogene, following the Variscan Orogeny and the assembly of Pangea, and prior to the Sardinia-Corsica drift associated with the opening of the western Mediterranean, the Sardinia lithospheric block formed part of the southern European continental margin. Reconstructing the tectonic evolution of Sardinia in this time interval is therefore essential to better understand the large-scale geodynamic processes and plate kinematics involving Europe, Iberia, Adria and Africa that ultimately lead to the Pyrenean, Alpine and Apennine orogenesis. However, the Mesozoic and Paleogene tectonic evolution of Sardinia remains poorly constrained. This contribution summarizes the main structural evidence for Mesozoic-Paleogene tectonics in Sardinia and attempts to correlate it with the major geodynamic events affecting the southern European margin.
The Mesozoic to Paleogene stratigraphic succession of Sardinia is characterized by unconformity-bounded stratigraphic gaps, folds and faults that record tectonic activity throughout this time interval. Notably, no evidence of syn-tectonic magmatic activity has been recognized. The tectono-stratigraphic record differs among the southwest, central-eastern and northwestern areas of Sardinia.
In southwestern Sardinia, the Mesozoic-lower Paleogene succession is deformed by N-S-trending folds and top-to-the-east thrusts. In particular, Upper Triassic dolostones and Lower Jurassic limestones are thrust over the lower Eocene succession. These structures are sealed by the Upper Eocene-Oligocene successions.
In central eastern Sardinia, the Mesozoic carbonate succession is affected by low-angle sinistral transtensional faults, along which several metres of the Jurassic and Cretaceous formations have been tectonically elided, and by superimposed top-to-the-SSE thrusts. The age of the deformation is constrained between the Santonian, represented by the youngest deformed strata, and the Oligocene-Lower Miocene strike-slip faults that crosscut the earlier structures. Farther south, Ypresian shallow-marine deposits lie unconformably above the Variscan basement and the Permian-to-Jurassic stratigraphic succession.
In northwestern Sardinia, an angular unconformity marked by bauxite deposits between the Lower and Upper Cretaceous records a tectonic event characterized by NW-SE-trending folds and ENE-striking sinistral transpressional faults, both coherent with a NE-SW shortening direction.
These observations indicate that Sardinia experienced a spatially heterogeneous tectonic evolution during the Mesozoic and Paleogene. The contrasting structural features likely reflect distinct paleogeographic positions relative to the evolving southern European margin. The compressional deformation in southwestern Sardinia is broadly coeval and is consistent with the main collision phase in the Pyrenees. Also, the Upper Eocene sediments that seal the structures in southwestern Sardinia may have been derived from the erosion of the eastern Pyrenean belt. The central-eastern and northwestern Sardinia tectonic evolution shows similarities with that of Provence, including a transition from transtensional to transpressional deformation from the Lower to the Upper Cretaceous. This transition may be related to the onset of subduction in the western Tethys along the southern European margin.
These correlations suggest that different sectors of Sardinia recorded the effects of distinct geodynamic processes operating simultaneously along the southern European margin. Further integration of the Sardinian record with those from the Eastern Pyrenees and Provence will provide new constraints on the tectonic evolution of the region prior to the opening of the western Mediterranean.
How to cite: Funedda, A. and Cocco, F.: Mesozoic to Paleogene tectonic evolution of Sardinia, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-69, https://doi.org/10.5194/egusphere-alpshop2026-69, 2026.
In this study, we present new zircon U-Pb geochronological and Lu-Hf isotope data from garnet-bearing micaschists and two-mica leucogranite exposed in the metamorphic core of the Juhor Mts., a part of the Northern Serbo-Macedonian Sub-unit (NSMU) in central Serbia. Zircon core analyses from both lithologies demonstrate total overlap in terms of geochronology and geochemistry, yielding dominant Middle Ordovician ages between ~460 and 480 Ma, and indicating widespread Ordovician thermo-magmatic activity within the NSMU. Subordinate inherited zircon populations record Neoproterozoic ages (~550-850 Ma), consistent with derivation from Cadomian peri-Gondwanan crustal domains. Zircon rims define several younger Silurian to Carboniferous age populations interpreted as reflecting prolonged tectonothermal evolution followed by Late Variscan thermal overprinting. Lu-Hf isotope compositions are characterized predominantly by mildly subchondritic εHf(t) values, indicating evolved crustal sources, whereas several inherited Neoproterozoic grains and subordinate Ordovician zircons preserve juvenile isotopic signatures suggestive of variable mantle contribution during Cadomian crust formation. The granitoid exhibits petrographic, geochronological, and isotopic characteristics consistent with peraluminous S-type magmatism derived largely from partial melting of metasedimentary crust. The obtained data indicate that the NSMU preserves fragments of a peri-Gondwanan basement affected by prolonged Early Paleozoic thermo-magmatic evolution broadly comparable to other Alpine basement domains. Despite strong Alpine deformation and exhumation documented in the Juhor area, no Alpine zircon growth or zircon recrystallization was detected in the analyzed samples.
How to cite: Maleš, M., Stojadinovic, U., Randjelovic, N., Sokol, K., Xie, J.-C., and Prelević, D.: Pre-Alpine thermal history of the Juhor Mts., central Serbia (Northern Serbo-Macedonian Sub-unit): Constraints from zircon U-Pb geochronology and Lu-Hf isotope geochemistry, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-18, https://doi.org/10.5194/egusphere-alpshop2026-18, 2026.
Repeated deformation, metamorphism, remelting and crustal recycling are the processes that shape orogens. The Serbo-Macedonian Massif (SMM) stretches from the Pannonian Basin in the north to the Aegean Sea in the south, bound by the Vardar Zone and the Circum-Rhodope Belt in the west and neighboured by the Rhodope Metamorphic Core Complex in the east. Its present-day shape and structure are conditioned by the Alpine and pre-Alpine orogenies. In particular, the Ograzhden Unit in SW Bulgaria has been proven to possess Proterozoic and Paleozoic magmatic and metamorphic ages (Peytcheva et al., 2015, Geol. Balc. 44), incl. evidence for UHP metamorphism at 334 Ma (Trapp et al., 2020, Terra Nova), in its high-grade orthometamorphic basement. Furthermore, shortly before the onset of the Alpine orogeny, Triassic magmatism imprinted the basement, recorded in the Igralishte granitic body (Peytcheva et al., 2009, Geol. Balc. 38).
In this study, we investigate the evolution of the Ograzhden Unit as a part of the SMM. We report a new 444.8±1.5 Ma U-Th-Pb zircon age of the Nikudin granite. The granite body shows geochemical characteristics suggestive of a S-type leucogranite formed in a convergent setting. The high-grade metamorphism in a metasediment from Lebnitsa is characterized by a peak mineral assemblage Q-Ms-Ky-Grt, and MnNCKFMASHT equilibrium thermodynamic modelling suggests ≥ 1.1 GPa at 620°C, suggesting that lower eclogite facies conditions were possibly reached in the subducted continental crust during the Variscan orogeny. Triassic magmatism recorded in the Igralishte granite (Peytcheva et al., 2009, Geol. Balc. 38) shows trace and rare earth element patterns indicative of a highly evolved, fractionated material, associated with a high degree of crystallization. The basement was then structured by the Alpine orogeny, starting with ductile deformation in lower amphibolite facies in the Cretaceous and characterized by top-to-SE kinematics. Thus, the Ograzhden Unit comprises heterogeneous material formed and deformed during several orogenic cycles, and finally shaped into its current structure by Alpine deformation.
How to cite: Jensen, A., Pleuger, J., Hoffmann, E., and Georgiev, S.: Alpine deformation and pre-Alpine evolution of the Ograzhden Unit, Serbo-Macedonian Massif, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-47, https://doi.org/10.5194/egusphere-alpshop2026-47, 2026.
This study presents a new paleontological data and microfacies analyses of the Aptian–Cenomanian successions of Kotraža (Central Serbia). The studied successions (Section 1 and Section 2) comprises four sedimentary cycles dated by ammonoids and foraminiferal biostratigraphy. Three fining-upward cycles in Section 1 record deepening-trends, whereas the fine-grained Section 2 more distal basin-ward sedimentation.
The Kotraža succession (Section 1) provides the first evidence of Early Albian volcanism (~112 Mio. yr) and the development of an atoll-like reef system around a volcanic island in Central Serbia, reflecting most likely the response of the Inner Dinarides to the mid-Cretaceous tectonic plate reorganization in the Western Tethys Realm. Based on new data, Cycle 1 of the Section 1 records the establishment of deep-marine sedimentation following the drowning of an orbitolinid-bearing carbonate ramp during the latest Aptian. The deposition of deep-water sediments intercalated with mass-transport deposits containing beside volcanic pebbles also different shallow-water organisms, volcanic ashes and sandstones during the Aptian-Albian transition interval, indicate that the volcanic activity triggered progressive deepening and reduction of shallow-water carbonate production, i.e. the drowning of the orbitolinid foraminifera-bearing shallow-water carbonate ramp, restricting shallow-water carbonate production to reefs surrounding the newly formed volcanic island. The Cycle 2 of the Section 1 is characterized by volcanoclastic sandstone turbidites, slumps and mass-transport deposits containing mixed fossil fauna. Fe-rich and glauconitic sandstones with mixed shallow- and deep-water fossil fauna document continued volcanically influence sedimentation and redeposition of shallow-water material into adjacent basinal environments during the emergence of volcanic island the Early Albian. However, the Middle Albian is not proven in the sedimentary succession, and the reason for it remains unclear. The Cycle 3 of Section 1 records a new phase of deep-marine sedimentation during the late Albian and is represented by a fining-upward succession of marlstones and claystones. The decreasing of volcanic ash layers indicates declining volcanic activity, and the appearance of the organic-rich fine-grained sediments reflect low-oxygen conditions associated to late Albian black-shale events. The Section 2 records only one cycle of late Albian transgressive phase characterized by fine-grained succession and decreasing volcanic activity, whereas aboundant planktonic foraminifera indicate open-marine basinal conditions. The uppermost part of the section is characterized by organic-rich sediments which indicate progressively restricted low-oxygen conditions, comparable to late Albian-early Cenomanian intervals recognized in the Western Tethys realm.
How to cite: Vuletić, M., Đaković, M., Gawlick, H.-J., Đerić, N., and Machaniec, E.: New biostratigraphic and microfacies study of the Kotraža successions: Evidence for Early Albian volcanism and the development of an atoll-like reef system in Central Serbia, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-12, https://doi.org/10.5194/egusphere-alpshop2026-12, 2026.
The localities Kovčezi, Brvenica, Jugovo and Vrbica (Pljevlja and Žabljak regions) preserve the depositional history of the Middle Triassic to early Late Triassic in the northern Montenegro. The sedimentological evolution, geodynamic history of the East Bosnian-Durmitor megaunit allows reconstructing from the Late Anisian break-up unconformity, i.e. the formation of a Horst-and-Graben structure to the onset and demise of the Early Carnian Wetterstein Carbonate Platform. All the studied sections record the geological history from the drowning of the shallow-water Ravni Carbonate Ramp in the late Pelsonian (Middle Anisian) to the demise of the Wetterstein Carbonate Platform around the Julian 1/2 boundary (Early Carnian) and the aftermath of carbonate production in the latest Carnian. During the middle Anisian, shallow-water limestone formation (Ravni Carbonate Ramp) changed rapidly to deposition of deep-water limestones forming a drowning unconformity. Contemporaneously with the demise of the shallow-water ramp a first horst-and-graben topography was formed, subsequently followed by a volcanic event. The demise and drowning of the Ravni Carbonate Ramp are related to the initial of the opening of the Neo-Tethys Ocean east of the present day Inner Dinarides. The late Pelsonian continental break-up and opening of the Neo-Tethys Ocean triggered formation of a Horst-and-Graben topography and a rapid decrease of shallow-water carbonate production throughout the Dinarides like elsewhere in the Western Tethys Realm. During this tectonostratigraphic event sedimentation changed rapidly from shallow-water carbonates to deep-water limestones. Later, around the middle/late Illyrian boundary the onset of volcanism (its cause remain unclear in the moment) in the Outer Dinarides resulted in the formation of a second unconformity. The first event can be traced everywhere in the Western Tethys Realm, but a second Horst-and-Graben topography was only formed in the Outer Dinarides. During latest Anisian to Early Carnian times a period of tectonic quiescence followed. Sedimentation is characterized by deep-water volcaniclastics, siliceous limestones or radiolarites, often intercalated with volcanic ash layers. Only in the short time interval of the early Late Ladinian in some regions shallow-water carbonates were formed. Generally deep-water conditions prevailed until the Early Carnian, when the situation changed and the Wetterstein Carbonate Platforms started to evolve on the late Anisian horsts. During the Early Carnian these Wetterstein Carbonate Platforms prograded towards the late Anisian grabens, but were not able to fill these depressions. Short-living intraplatform basins therefore remain, and can be traced between the prograding platforms. These earned depressions could not be filled by carbonates, because the evolution of this platform cycle ended abruptly around the Julian 1/2 boundary, in addition, these platforms were uplifted and during the Carnian deeply eroded.
How to cite: Mrdak, M., Gawlick, H.-J., Sudar, M., Djerić, N., and Đaković, M.: Middle-Late Triassic sedimentological history in northern Montenegro: From the drowning of the Ravni Carbonate Ramp to the Wetterstein Carbonate Platform evolution, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-14, https://doi.org/10.5194/egusphere-alpshop2026-14, 2026.
The Timok Magmatic Complex (TMC) represents a segment of the wider Apuseni–Banat–Timok–Srednogorie (ABTS) Late Cretaceous magmatic belt, formed in response to the roll-back of the Neotethys slab beneath the Carpatho-Balkanides orogen in SE Europe. The TMC basin comprises Upper Cretaceous volcano-sedimentary sequences structurally incorporated within the Getic nappe system of the Serbian Carpathians. The evolution of the TMC basin was governed by Albian–Cenomanian to Turonian–Campanian E–W- to NE–SW-oriented extension associated with syn-tectonic calc-alkaline magmatism (~88–76 Ma). The post-rift stage of the basin evolution is characterized by Campanian–Maastrichtian shallow-marine carbonate sedimentation and regressive molasse deposits. The shallow-marine sediments, generally known as the “Vrbovac Beds”, were investigated at two localities in the southern part of the TMC basin. The lower parts of the Vrbovac Beds consist of coarse-grained carbonate breccia containing fragments of andesitic volcanites, corresponding to the final magmatic episode in the TMC basin. The upper parts comprise a succession of clastites and carbonates with diverse associations of rudists, gastropods, corals, and macroforaminifera. Carbonates are predominantly calcarenites, calcrudites, and biomicrites, whereas the clastic sediments include fine- to coarse-grained sandstones, marlstones, and shales. At the Bačevica locality, fossiliferous horizons are poorly exposed and two levels are recognized. The first level consists of loosely cemented limestone blocks with a diverse shallow-marine assemblage dominated by large rudists (Pironaea), gastropods (Trochactaeon giganteus Sowerby), and solitary corals (Cunnolites). Due to the weak cementation, material from this horizon is partly reworked and incorporated into second fossiliferous horizon, which is characterized by a rudist-dominated assemblage with Vaccinites loftusi, Radiolites sp., Pseudopolyconites sp., and Laperousia sp. In contrast, the Dubrava locality succession is subhorizontal and thin-bedded and well-preserved rudist in growth position indicate an autochthonous position. The rudist assemblage is comparable to that at Bačevica, and dominated by Vaccinites loftusi, Radiolites angeoides, and Pseudopolyconites sp., but lacks Pironaea. Cunnolites and large Trochactaeon specimens. During the Campanian–Maastrichtian, rudists and associated shallow-marine fauna inhabited depositional environments along the margins of the active andesitic Timok volcanic complex. The infill of rudist shells consists of siliciclastic material (quartz and clay minerals), indicating terrigenous input and deposition in clastic influenced environment. The studied sections record a transition from relatively high-energy depositional conditions at Bačevica to more stable environmental settings at Dubrava. Rudist habitats stretched from protected and open-marine parts of platforms to shelf margins where they produced large amounts of bioclastic rudist sands as observed at Bačevica.
By linking stratigraphic, sedimentological, and tectonic observations, this study provides new constraints on the late evolutionary stages of the Upper Cretaceous TMC basin.
Keywords: biostratigraphy; sedimentology; paleoenvironments; Timok Magmatic Complex; Serbian Carpathians
How to cite: Djordjevic, B., Djerić, N., Maleš, M., Grujovski Stanislavljević, M., Ranđelović, N., and Stojadinović, U.: Biostratigraphy and paleoenvironments of post-rift sedimentation in the Upper Cretaceous basin of the Timok Magmatic Complex (Serbian Carpathians), 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-15, https://doi.org/10.5194/egusphere-alpshop2026-15, 2026.
The Upper Jurassic–Lower Cretaceous Krčedin succession, situated on the eastern foothills of the metamorphic Fruška Gora Mountains (Serbia), comprises mixed carbonate–siliciclastic deposits, including hemipelagic marlstones, radiolarian-spicule-bearing deposits, carbonate turbidites and breccias. The lower part of the succession is characterized by alternating marly limestones and redeposited shallow-water carbonate material, including partially silicified crinoidal limestones, peloidal limestones, and carbonate breccias containing shallow-water biota. Upsection, marlstone sedimentation becomes dominant and is characterized by pyrite-rich and organic-rich intervals, black shale horizons, and the presence of trace fossils (Chondrites, Planolites). The upper part of the section is represented by quartz-rich siliciclastic turbidites showing a pronounced coarsening-upward trend and is unconformably overlain by transgressive rudist-bearing marly limestones. Thin sections prepared from the carbonate turbidites, and the fine-grained interbedded sediments were analysed for micropaleontological and microfacies data. The redeposited assemblages are dominated by dasycladalean algae, including Salpingoporella pygmaea, Aloisalthella sulcata, and Thaumatoporella parvovesiculifera. The foraminiferal assemblage includes Mohlerina basiliensis, Pseudocyclammina lituus, Redmondoides lugeoni, and Nauticulina sp. The presence of Aloisalthella sulcata, Pseudocyclammina lituus, and Mohlerina basiliensis indicates a (Kimmeridgian–)Tithonian age for the source area of these redeposited shallow-water bioclasts. The studied carbonate turbidites document the existence of a nearby carbonate platform. Late Jurassic carbonate platforms are known from the Dinarides, where carbonate platforms developed on top of the obducted ophiolites, as well as from the Southern Carpathians and related Getic units. However, the entire sedimentary succession of Krčedin is markedly different from successions known from the Getic units or the Balkanides. Therefore, carbonate breccias containing both shallow marine redeposited bioclasts and ophiolitic clasts provide strong evidence for Dinaridic provenance.
How to cite: Djordjevic, B., Gawlick, H.-J., Djerić, N., Reháková, D., Uchman, A., and Pleș, G.: Evidence for a Late Jurassic Carbonate Platform in the Source Area of the Krčedin Succession (Fruška Gora, Serbia) , 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-16, https://doi.org/10.5194/egusphere-alpshop2026-16, 2026.
The East Vardar Ophiolites and their provenance are still a matter of controversial discussion. Most authors place these ophiolites east of a proposed Sava suture zone. To provide new data for the discussion, we studied a series of units north of Parallova village, Gjilan area (SE Kosovo), where two different tectonic units could be distinguished.
The lower unit consists of metamorphosed Late Triassic–Jurassic carbonates. The succession starts with shallow-water open-lagoonal Dachstein carbonates overlain by reefal to fore-reefal limestones, followed by non-recrystallized shallow-water limestones with well-preserved microfacies, and Early Jurassic limestones. The identified microfacies correspond to transitional facies between the Lithiotis Carbonate Ramp and the drowned Dachstein Carbonate Platform. This metamorphosed succession shows similarities to the Pelagonia domain of the Hellenides.
The upper unit consists of non-metamorphosed ophiolites with ophiolitic mélanges at the base, comprising an OM3-type mélange overlain by an OM2-type mélange, and an overlying Tithonian overstep sequence. The ophiolitic unit is relatively thin compared to other ophiolite units in the Dinarides–Albanides–Hellenides, indicating deep erosion. This sequence begins with a basal conglomerate that locally contains metre-sized blocks of recrystallized shallow-water carbonates and fills depressions of the erosional unconformity. Upsection, carbonate beds contain shallow-water bioclastic material derived from a carbonate platform margin and platform interior comparable to the Kurbnesh Carbonate Platform. The carbonate clasts yield a rich microfossil assemblage including Mohlerina basiliensis, Neokilianina rahonensis and Labyrinthina mirabilis, indicating a Kimmeridgian–Tithonian age. The succession continues upward into turbiditic deposits showing a fining-upward trend and ultimately passes into organic-rich marls of probable Berriasian–Valanginian age.
The overlying succession resembles the Tithonian/Berriasian–Valanginian Firza Formation in Albania, sealing the obducted ophiolites and contains reworked reefal material derived from the Kurbnesh Carbonate Platform. In the so-called East Vardar zone, this succession corresponds to the “Paraflysch sequence” and shows close similarities to successions known from the Axios Zone and the Vardar Gorge in Macedonia, deposited above the eastward downgliding ophiolites during Tithonian und younger uplift and unroofing. The succession records post-obduction uplift, erosion, and progressive basin deepening. Continued unroofing is reflected by the fining-upward trend of the turbiditic succession.
Keywords: Neo-Tethys, East Vardar, ophiolites, Paraflysch, turbidites
How to cite: Bilalli, B., Gawlick, H.-J., Prela, M., Pleș, G., Onuzi, K., and Uta, A.: A deeply eroded ophiolitic unit above metamorphosed Late Triassic Jurassic carbonates and below a Tithonian and younger turbiditic overstep sequence (Gjilan Area, SE Kosovo): evidence for Neo Tethyan ophiolites obducted during the Middle Late Jurassic, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-22, https://doi.org/10.5194/egusphere-alpshop2026-22, 2026.
The extraordinary Western Carpathian tectonic structure, the Pieniny Klippen Belt (PKB), is characterized by its complex internal structure, particular tectonic units and a range of specific lithostratigraphic formations. Among them, the terminating coarsening-and-thickening upward deep marine clastic formations record the sequential thrust propagation of the principal Oravic tectonic units of the PKB. The Oravic palaeogeographic domain included the southern Kysuca–Pieniny basin (later Pieniny nappe) as a marginal part of the South Penninic oceanic realm (Piemont–Ybbsitz–Váh ocean) that separated the Oravic continental ribbon from the Central Carpathian (Austroalpine) realm. The central Czorsztyn ridge and its rifted slopes formed the Subpieniny unit, while the northern ridge foots (Šariš unit) were facing the North Penninic ocean (present Magura units). This pattern resulted from complex rifting and breakup episodes related to opening of the Alpine Atlantic during the Jurassic – Early Cretaceous.
The syn-orogenic clastic sedimentation commenced in the inner Pieniny basin during the Coniacian–Santonian. Material of siliciclastic turbidites and mass-flow conglomerates was derived from advancing fronts of the Central Carpathian Fatric cover nappe system (e.g. Klape nappe). The clastic material was largely recycled from mid-Cretaceous “exotic” conglomerates related to intra-continental subduction that generated the Fatric nappes. Distal northern turbidite lobes reached slopes of the Czorsztyn ridge and bypassed it up to the Šariš depositional area, so forming a large-scale, northward thinning classic wedge.
After elimination of the Váh ocean, shortening progressed by detachment of the Pieniny unit and its thrusting over the Czorsztyn ridge. This event is recorded by deposition of the Maastrichtian–Danian calcareous wildflysch complex that was terminated by olistostromal breccias composed of erosional debris released from the Pieniny nappe fronts. After the basement of the Czorsztyn ridge was thrust under the Central Carpathian orogenic wedge, its variable cover successions were attached to the developing Oravic accretionary complex. Depended on the variable sedimentary settings and resulting heterogeneous composition, sedimentary successions of the Subpieniny unit were partly fragmented and gravitationally transported by mass-wasting mechanisms to the northern Šariš basinal area. Consequently, the Maastrichtian to Lower Eocene calcareous wildflysch of the Šariš unit is inserted by huge bodies of olistostromes and (mega)olistoliths derived predominantly from the Subpieniny successions. As a matter of fact, numerous klippen that gave the name to the entire PKB are olistoliths, in addition to the tectonic klippen that originated by deformational disintegration of competent sedimentary layers and their embedding in incompetent matrix formations.
How to cite: Plašienka, D., Madzin, J., Molčan Matejová, M., and Potočný, T.: Syn-orogenic clastic deposits reveal the thrust propagation of the Oravic units (Pieniny Klippen Belt, Western Carpathians), 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-40, https://doi.org/10.5194/egusphere-alpshop2026-40, 2026.
Key words: microfacies, carbonate factory, Getic Carbonate Platform
The Getic Carbonate Platform (GCP) represents a Mesozoic sedimentary system developed on the southern margin of the European plate. It is coeval with other complex and well-studied carbonate platforms of Western Tethys, such as the Helvetic, Jura and Moesian carbonate platforms. Continuous sedimentation within the GCP during Late Jurassic–Early Cretaceous resulted in several thousand meters thick successions of carbonate and mixed siliciclastic-carbonate successions, cropping out in Romania, Serbia and Bulgaria. The stratigraphic evolution of the depositional system from a shallow-water carbonate platform to a mixed system influenced by terrigenous input, and finally the recovery of the shallow-water carbonate platform was studied in southeastern Serbia, in the proximity of Dimitrovgrad.
Facies analysis integrating the field data with microfacies petrography was conducted on more than 300 thin-sections within 12 stratigraphic logs. Sedimentary analysis additionally incorporated geochemical data from Oxygen and Carbon isotope analysis (δ¹³C, δ¹⁸O), SEM-EDS and Rock-Eval pyrolysis, depending on the characteristics of the sedimentary portion.
The Lower Cretaceous sedimentary succession of Dimitrovgrad was divided into three time slices (Berriasian-Valanginian, Valanginian-Hauterivian, and Barremian-Aptian) characterized by the lithology, either pure carbonates or mixed siliciclastic-carbonates, and type of the carbonate factory (photozoan carbonates dominated by the light-dependent skeletal carbonate producers or heterozoan association with filter-feeder biota). The variations of distinctive sedimentary features are the results of terrigenous input, tectonic activity and climate changes.
The Berriasian-Valanginian interval is dominated by the photozoan carbonate factory with Bacinella/Lithocodium, rudists, calcareous and siliceous sponges, which formed patch reefs. Within this interval the episodes of subaerial exposure were followed by platform drowning. The subsequent increase in terrigenous supply disturbed the carbonate platform leading to a transition to the heterozan carbonate factory of the Valanginian-Hauterivian interval. The filter-feeders such as bryozoans, crinoids, large bivalves and serpulids were the main carbonate producers. A common characteristic of this mixed siliciclastic-carbonate system was the deposition of ooid-rich facies as a result of the chemical factory taking the lead during high levels of seawater acidification. The recovery into a renewed shallow-water photozan carbonate platform is marked by rudist, calcareous and siliceous sponge rich facies with reefs of Barremian-Aptian interval.
The GCP represents a complex sedimentary system reflecting the Early Cretaceous tectonics of the Vardar–Ceahlau-Severin interaction domain, global climatic warming, ocean acidification and nutrient input during global perturbations of the carbon cycle and regional sedimentary regimes. A similar evolution pattern was recognized in other Western Tethys domains, confirming the influence of the same controlling factors.
How to cite: Stefanović, J., Della Porta, G., and Radivojević, D.: Lower Cretaceous Getic Carbonate Platform: transition from photozoan to heterozoan carbonate factory (South-eastern Serbia), 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-71, https://doi.org/10.5194/egusphere-alpshop2026-71, 2026.
