The Adriatic microplate (Adria) is a key player in the geodynamics of the Alpine–Mediterranean area, representing a fragment of continental lithosphere caught between the converging Eurasian and African plates. Adria’s motion and deformation have shaped the evolution of the surrounding collisional and subduction systems, including the Alps to the north, the Apennines to the west, and the Dinarides-Hellenides to the east. This complex setting renders kinematic reconstructions of Adria’s past motion very challenging. While GNSS data clearly show that Adria currently undergoes independent counter-clockwise motion, the timing of onset of its independent motion and the processes driving this change remain debated.
Over the past decades, tectonic reconstructions, geodesy, geophysical imaging, and geodynamic modelling have shifted the view of Adria from a rigid promontory of Africa to an actively evolving microplate interacting with complex plate boundaries. This presentation reviews recent developments in our understanding of Adria's kinematic evolution, focusing especially on advances in high-resolution 3D thermo-mechanical modelling. These models, integrated with geological observations, provide new perspectives on the role of subduction dynamics and mantle flow in driving Adria’s motion, and highlight the links between Adria’s kinematics and major Neogene tectonic events.
The independence of the Adriatic microplate likely reflects a progressive geodynamic reorganisation driven by subduction dynamics, mantle flow, and crustal deformation, leading to mechanical decoupling between Adria and Africa. Understanding this transition and the underlying processes provides a unique opportunity to explore how microplates form and evolve, and how plate reorganisations influence the evolution of orogenic belts.
How to cite: Le Breton, E.: Timing and drivers of Adria's independent motion: where do we stand?, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-63, https://doi.org/10.5194/egusphere-alpshop2026-63, 2026.
Due to the complexity inherent to the systems, the interpretation of the structure of the Northern Calcareous Alps and Inner Western Carpathians has traditionally relied on assuming a simplified pre-contractional configuration. The assumptions made include, for instance, that stratigraphy was either layer-cake or that it varied linearly from proximal to distal facies, that there is no or only limited decoupling between cover and basement during extension, and that rift systems have a one-directional distribution from proximal to distal domains. In the case of the Eastern Alps and Western Carpathians, these starting assumptions require complex interpretations of the orogenic structure, many of which have internal contradictions such as conflicting orogenic vergence or the unresolved debate on presence and/or the location of Mesozoic oceanic domains.
We argue that by incorporating modern concepts of salt tectonics and of rift system development, some long-standing paradoxes in these orogens can be successfully addressed. In the Eastern Alps, the development of a salt-rich rift system can explain the origin of the pelagic Hallstatt facies without requiring the presence of an oceanic domain. In the Western Carpathians, the presence of salt in a hyper-extended rift system can explain the confusing relationships of the Silica and its neighboring tectonic units as well as the apparent absence of its original basement. Incorporating the non-linear development of rift systems in turn can explain the nature of Mesozoic oceanic domains, from the Eastern Alps to the Western Carpathians.
In this contribution we review the key aspects of salt tectonics and rift systems that we believe could contribute to the understanding of the Eastern Alps and Western Carpathians and how they may be explored for in other segments of the Dinaric-Caraptho-Balkan system.
How to cite: Kövér, S., Fernandez, O., Fodor, L., Potočný, T., Csicsek, L. Á., Ortner, H., Sanders, D., Molčan-Matejová, M., Plašienka, D., Mazur, S., Soni, T., Rowan, M. G., Muñoz, J. A., Manatschal, G., and Grasemann, B.: Bringing pre-orogenic salt and rifts into the picture: What can we learn about the Eastern Alps and Western Carpathians?, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-53, https://doi.org/10.5194/egusphere-alpshop2026-53, 2026.
The Koralpe–Saualpe–Pohorje Complex (KSPC) in the Eastern Alps represents a key segment of the Austroalpine basement and hosts the type locality of eclogite. Despite extensive study, its tectono-metamorphic evolution remains debated, particularly regarding a proposed NW–SE increase in pressure–temperature conditions and possible ultra-high-pressure metamorphism in the Pohorje unit. Structural analysis of the KSPC reveals four deformation phases recording a polyphase tectonic evolution: D1 pre-Alpine deformation with E–W-trending stretching lineation and isoclinal folding, D2 Alpine deformation with NW–SE-trending stretching lineation and isoclinal folding, D3 development of Plattengneis fabric with N–S foliation, and D4 late E–W open folding.
We present new constraints from quartz-in-garnet elastic barometry, Zr-in-rutile thermometry, garnet diffusion modelling and in-situ U–Pb dating of garnet and rutile along a NW–SE transect from Koralpe to Pohorje. This study provides the first application of quartz-in-garnet barometry within the KSPC.
Eclogite samples yield consistent maximum entrapment pressures of ~1.85 GPa across the entire complex, with no systematic spatial variation. Metasedimentary rocks record lower pressures of up to ~1.4 GPa. Zr-in-rutile thermometry indicates uniform peak temperatures of 640 ± 30 °C, likewise showing no thermal gradient. In addition, garnet diffusion modelling suggests short residence times at peak P–T conditions, consistent with rapid burial and exhumation.
Garnet U–Pb ages cluster in the Early Cretaceous (~95–105 Ma), with eclogitic garnet from Koralpe yielding ~112 Ma. A Saualpe metasedimentary sample preserves Triassic garnet cores (~224 Ma) overgrown by Early Cretaceous rims (~115 Ma), indicating polymetamorphic overprinting. Rutile U–Pb ages range from ~98–80 Ma and are interpreted as cooling ages.
Overall, the data suggest that the KSPC is best explained as consisting of several subnappes rather than a single coherent nappe. The absence of a systematic P–T gradient, together with uniform peak conditions, argues against the previously proposed NW–SE metamorphic gradient. Apparent pressure differences between lithologies are most plausibly attributed to fluid-assisted modification of quartz-in-garnet systems rather than primary metamorphic variations. Together with the identified four deformation phases, our results support a homogeneous peak metamorphic overprint within a polyphase tectonic framework.
How to cite: Wannhoff, I., Pleuger, J., Zhong, X., John, T., Millonig, L. J., Schuster, R., Gerdes, A., and Albert, R.: New petrological and geochronological constraints on the Koralpe–Saualpe–Pohorje Complex (Eastern Alps), 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-8, https://doi.org/10.5194/egusphere-alpshop2026-8, 2026.
In the NE Tauern Window, bedrock mapping across the Penninic nappes documents substantial deformation transitioning from nappe stacking to extensional tectonics. The Oligo-Miocene deformation record is interpreted as W-E extension accompanied by a component of N-S shortening during the switch from compressional thickening to extensional exhumation. Kinematic indicators (e.g. winged inclusions, tiling, and climbing pinch-and-swell veins) consistently indicate a top-to-E shear sense, confirming progressive east-directed transport under ductile conditions. Quantitative estimates of ductile flow are derived from structurally rotated quartz-calcite-dolomite veins, highlighting that deformation is shared approximately equally between pure shear and simple shear components. Ductile folding is characterized by sub-horizontal axial planes of late structures, which imply vertical flattening during ductile flow. This ductile regime is overprinted by E-dipping shear bands and faults, which evolve into brittle-ductile faults consistent with incremental strain axes that also indicate vertical shortening during top-to-E extension. Geochronology from white mica Ar-Ar dating from both shear veins and recrystallized fabrics indicates Oligocene (c. 25-34 Ma) deformation ages. The deformation pattern suggests distributed ductile thinning in the footwall of an extensional detachment systems, motivating investigation toward higher crustal levels. At the upper limit of the Nordrahmen Zone, deformation localizes into the newly identified top-to-E Schuhflicker Detachment, a knife-sharp ultramylonite-cataclasite fault surface. The hanging wall comprises slightly deformed Lower Austroalpine quartzites and dolomites. Eleven apatite fission track ages from the Schuhflicker footwall were incorporated with apatite grain-specific chemistry for thermal history modeling, indicating c. 11-7 Ma cooling in the sub-dome core (~17°C/Myr) consistent with Miocene folding and exhumation of the eastern Tauern Window. However, earlier c. 19-13 Ma cooling (~12°C/Myr) below the detachment is interpreted as unroofing of the Schuhflicker footwall prior to and during Miocene doming. Estimated cumulative unroofing associated with this tectonic phase is 22.4 ± 4.4 km between 30 and 19 Ma, and as much as 26 km of total exhumation of the Penninic Unit since the early Oligocene. The Schuhflicker Detachment formed at mid-crustal depths during the Oligocene, after which W-E extension migrated structurally upward during the Miocene to the Katschberg Fault and Katschberg Shear Zone System. Collectively, these structures define the East Tauern Detachment System. The results support a progressive exhumation history combining tectonic unroofing and surface erosion, while accounting for the proposed >20 km of exhumation since the Oligocene that has been suggested for parts of the Tauern Window.
How to cite: Schneider, D., Spalding, J., Huet, B., and Grasemann, B.: The East Tauern Detachment System and its role in the Oligo-Miocene exhumation of the Tauern Window, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-19, https://doi.org/10.5194/egusphere-alpshop2026-19, 2026.
Tectonic mélanges formed of oceanic rocks provide key observations on the chemical, thermal and mechanical processes active at the plate interface of oceanic subduction zones. Mélanges formed of continental rocks are less documented, though they potentially provide similar observations pertaining to continental subduction and collision. Here, we present a geometric and lithological characterization of tectonic mélanges formed of continental rocks based on comprehensive mapping in the Tauern Window (Rauris and Zirknitz valleys, Austria).
The investigated melanges comprise mostly well identifiable cover and basement units formed prior to the opening of the Alpine Tethys, occurring juxtaposed without lithostratigraphic coherence. They are strongly deformed and show systematic top-to-the-N shearing consistent with the subduction and collision kinematics. Field observations allow to distinguish four mélange types based on their thickness, the degree of continuity, the tectonic position as well as the occurrence of a matrix and its nature.
Type 1 mélanges are continuous, several hundreds of meters thick and located directly above thick and coherent continental nappes. The matrix is composed of Carboniferous and Jurassic-Cretaceous schists. Within it are found large lenses of metasediments from all known Permo-Triassic lithostratigraphic units, together with rare orthogneiss. A Type 2 mélange occurs as a single 100-200 m thick continuous unit between oceanic nappes. The matrix is composed of Jurassic-Cretaceous schists containing smaller lenses of the same lithologies as described for type 1 mélanges. Additionally, a discontinuous and heterogeneous slab of orthogneiss occurs. In contrast, type 3 mélanges are characterized by the absence of a matrix and a thickness of less than 20 m. They are built of slivers composed of a single lithostratigraphic unit that alternate within the mélange at meter to kilometer scale. Metasediments of possible oceanic origin are locally observed. Finally, type 4 mélanges are strictly speaking not mélanges. They correspond to strings of 1-5 m thick boudins of Triassic marble found within oceanic nappes.
We interpret the four identified mélange types as a mixture of cover and basement units scraped off the down going plate during continental subduction. The evolution from mélange type 1 to type 4 corresponds to an increase of strain. The occurrence of up to three mélanges sandwiched between oceanic nappes on each investigated profile, indicate out-of-sequence thrusts within the hanging wall oceanic unit active during collision subsequent to continental subduction.
The units described here are not an exception in the Tauern Window. A mélange of type 3 can be followed over more than 100 km all around the Eastern Dome. Additionally, the Eclogite Zone shares many similarities with the type 2 mélange. As such, our observations raise several questions: Are mélanges formed of continental rocks widespread in the Alpine-Mediterranean orogenic system? Why are continental elements scraped off whereas deformation is expected to localize in weak oceanic metasediments or serpentinite? Why are oceanic rocks barely found in the mélanges? Why did thickening compartmentalize independently within continental and oceanic units during collision?
How to cite: Huet, B., Költringer, C., Tagliaferri, A., and Rogowitz, A.: Tectonic mélanges formed of continental rocks in the Tauern Window, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-21, https://doi.org/10.5194/egusphere-alpshop2026-21, 2026.
The paleomagnetism of Miocene calc-alkaline volcanics and sediments from Sardinia has firmly showed that the Corsica-Sardinia microplate rotated 50°-60° counterclockwise (CCW) with respect to Europe between 21 and 15 Ma, during its drift from the Provencal margin. However, Permian to Eocene rocks from central-south Sardinia revealed higher (up to 120°) CCW rotation values that implied contrasting kinematic models for pre-Miocene times. Late Permian block rotations, a connection with the Brianconnais and closure of the Valais Ocean, and Oligocene assembly of two Sardinian sub-microplates of Iberian and European affinity were advocated. In such frame, a total post-Permian 60° CCW rotation of N Sardinia-S Corsica was considered a first-order constraint, given the solid database from Permian dykes and volcanics gathered there. Here we report on the paleomagnetism of 38 sites from Permian, Triassic, Jurassic, and Cretaceous sediments (and one ignimbrite) from Nurra (NW Sardinia). All sites are located on the same crustal sub-block, thus are pivotal to constrain rotation timing. We find that Lower Triassic to Upper Cretaceous sediments consistently show a ~90° CCW rotation, whereas Permian data reveal a ~30° clockwise (CW) rotation occurring in the 290-250 Ma time window. We conclude that the Oligo-Miocene CCW rotation of a Sardinia-S Corsica area must be increased to a 90° value, of which 30° occurred before 21-15 Ma microplate drift. The Permian 30° CW rotation occurred 90-50 Myr earlier than Central Atlantic rifting episodes, eventually leading to Pangea breakup. Thus, it unquestionably testifies an intra-Pangean microplate mobility significantly pre-dating its fragmentation.
How to cite: Siravo, G., Speranza, F., and Oggiano, G.: Paleomagnetic evidence from Permian-Cretaceous sediments of Nurra (NW Sardinia) show a post-Eocene 90° CCW rotation of Sardinia-South Corsica and Permian 30° CW rotation of Nurra (NW Sardinia), 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-9, https://doi.org/10.5194/egusphere-alpshop2026-9, 2026.
Subduction zones and collisional orogens exhibit a wide spectrum of surface responses that reflect evolving slab and mantle dynamics. Yet distinguishing the topographic and sedimentary signatures of variable trench motions, lithospheric delamination, slab tearing, and eventual slab break-off remains a major challenge. Here I explore how sedimentary basins and mountain belts record these deep geodynamic processes, focusing on the Alps–Carpathians system as a natural laboratory.
Using a combination of two-dimensional and three-dimensional thermo-mechanical models incorporating surface processes, sedimentation, hydration, melting, and magmatism, I investigate the evolution of forearc, foreland, and back-arc basins throughout the subduction cycle. The results demonstrate that slab advance and slab steepening generate long-wavelength dynamic subsidence and forearc basin development, whereas slab roll-back promotes upper-plate extension, arc rifting, lithospheric thinning, and back-arc basin formation.
These processes are illustrated through the Miocene evolution of the Alpine–Carpathian region, where eastward Alpine extrusion was coupled to Pannonian back-arc extension, Transylvanian forearc subsidence, and progressive uplift of the Carpathian arc during mantle lithosphere delamination and subsequent slab break-off. New results further examine the evolution of magmatism during the transition from roll-back to delamination and final slab detachment.
I discuss recent 3D models of slab tearing beneath collisional belts. Incorporating realistic passive-margin heterogeneity significantly slows tear propagation and generates long-lived tectonostratigraphic signals, including migrating depocenters and systematic basin asymmetries. These predictions provide a framework for interpreting observations from the Alps and other mountain belts, linking mantle-scale processes to preserved stratigraphic records.
Together, these results highlight how basin subsidence, uplift, magmatism, and sedimentary architecture can be used to discriminate between successive stages of subduction-zone evolution, offering a unified perspective on the surface expression of slab dynamics from active subduction to continental collision and post-collisional collapse.
How to cite: Balázs, A.: Reading Deep Mantle Processes from Sedimentary Basins, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-20, https://doi.org/10.5194/egusphere-alpshop2026-20, 2026.
Horizontal slab tearing, the lateral detachment of a subducting oceanic slab from continental lithosphere, is widely inferred from seismic tomography, yet its surface expressions in mountain belts and foreland basins remain ambiguous and, in many cases, contradictory. Existing geodynamic models commonly predict rapid horizontal tear propagation, implying that associated surface and stratigraphic signals should be too transient to be preserved in the geological record. In contrast, field observations, including lateral migration of foreland-basin depocenters and systematic basin thickening in the direction of inferred tear propagation, suggest more persistent and coherent surface responses. This discrepancy highlights a long-standing disconnect between geodynamic model based predictions and geological evidence. Here, we resolve this paradox by demonstrating that lateral variations in passive-margin strength exert a first-order control on the initiation, propagation, and surface expression of horizontal slab tearing. Using fully coupled three-dimensional thermo-mechanical and surface-process simulations, we show that passive-margin strength heterogeneity can substantially slow tear propagation and generate long-lived tectonostratigraphic signatures consistent with natural examples from the Alps, Carpathians, Zagros, and other orogenic belts. Our results bridge deep mantle dynamics and foreland-basin records, providing a unified framework for identifying, interpreting, and reconstructing slab tearing in orogenic systems worldwide.
How to cite: Maiti, G., Andrić-Tomašević, N., Balázs, A., Eskens, L. H. J., and Gerya, T.: Slab tearing and its signals in foreland basins controlled by passive margin strength, 17th EGU Émile Argand Conference on Alpine Geological Studies, Fruška Gora, Serbia, 14–16 Sep 2026, alpshop2026-39, https://doi.org/10.5194/egusphere-alpshop2026-39, 2026.
