Unraveling the age and kinematics of low temperature deformation events is crucial in understanding the late‐stage evolution of orogens. However, accurate age constraints can often be challenging to ...obtain due to unideal outcrop conditions, large sedimentary hiatuses or the lack of well‐defined thermal events. In this study, we show on the example of the Nekézseny Thrust, a poorly exposed late orogenic thrust in the southern Western Carpathians, that a combined approach of structural analysis and multi‐method thermochronology can provide the necessary temporal, kinematic and thermal constraints for a detailed reconstruction of the deformation history. While structural mapping revealed that the Late Cretaceous Uppony Gosau Basin in the footwall of the Nekézseny Thrust underwent a significant post‐Campanian and pre‐Miocene shortening, K/Ar dating of fault gouge samples from the main fault zone constrained the primary thrusting event to the Maastrichtian. Based on the acquired apatite fission‐track and (U‐Th)/He ages, subsequent heating of the Upper Cretaceous sediments due to tectonic burial was limited to 75–100°C, followed by deformation‐related and gradual cooling between the Eocene and Early Miocene. Considering the reconstructed deformation history, as well as the large‐scale tectonic affinity of the displaced units in its footwall and hanging wall, the Nekézseny Thrust is a far‐traveled (ca. 600 km) segment of the Late Cretaceous Alps‐Dinarides contact zone, whose development was linked to the switch from lower plate to upper plate position with respect to the Sava Zone and Alpine Tethys sutures, respectively.
Key Points
Detailed structural analysis is combined with three thermochronological methods to reconstruct low temperature deformation events
K/Ar age of fault gouges date the fault activity directly, while apatite fission‐track and (U‐Th)/He data constrain the exhumation history
The Maastrichtian age of the Nekézseny Thrust is interpreted in lights of the late‐stage Alpine‐Carpathian‐Dinaric tectonic evolution
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The Adriatic Carbonate Platform (AdCP) is one of the largest Mesozoic carbonate platforms of the Perimediterranean region. Its deposits comprise a major part of the entire carbonate succession of the ...Croatian Karst (External or Outer) Dinarides, which is very thick (in places more than 8000 m), and ranges in age from the Middle Permian (or even Upper Carboniferous) to the Eocene.
However, only deposits ranging from the top of the Lower Jurassic (Toarcian) to the top of the Cretaceous can be attributed to the AdCP (defined as an isolated palaeogeographical entity). Although the entire carbonate succession of the Karst Dinarides was deposited within carbonate platform environments, there were different types of carbonate platforms located in different palaeogeographical settings. Carboniferous to Middle Triassic mixed siliciclastic–carbonate deposits were accumulated along the Gondwanian margin, on a spacious epeiric carbonate platform. After tectonic activity, culminating by regional Middle Triassic volcanism recorded throughout Adria (the African promontory), a huge isolated carbonate Southern Tethyan Megaplatform (abbreviated as STM) was formed, with the area of the future AdCP located in its inner part.
Tectonic disintegration of the Megaplatform during the middle to late Early Jurassic resulted in the establishment of several carbonate platforms (including the Adriatic, Apenninic and Apulian) separated by newly drowned deeper marine areas (including the Adriatic Basin as a connection between the Ionian and Belluno basins, Lagonero Basin, and the area of the Slovenian and Bosnian troughs). The AdCP was characterised by predominantly shallow-marine deposition, although short or long periods of emergence were numerous, as a consequence of the interaction of synsedimentary tectonics and eustatic changes. Also, several events of temporary platform drowning were recorded, especially in the Late Cretaceous, when synsedimentary tectonics became stronger, leading up to the final disintegration of the AdCP. The thickness of deposits formed during the 125 My of the AdCP's existence is variable (between 3500 and 5000 m).
The end of AdCP deposition was marked by regional emergence between the Cretaceous and the Palaeogene. Deposition during the Palaeogene was mainly controlled by intense synsedimentary tectonic deformation of the former platform area—some carbonates (mostly Eocene in age) were deposited on irregular ramp type carbonate platforms surrounding newly formed flysch basins, and the final uplift of the Dinarides reached its maximum in the Oligocene/Miocene.
The Adriatic Carbonate Platform represents a part (although a relatively large and well-preserved one) of the broader shallow-water carbonate platform that extended from NE Italy to Turkey (although its continuity is somewhat debatable in the area near Albanian/Greece boundary). This large carbonate body, which was deformed mostly in the Cenozoic (including a significant reduction of its width), needs a specific name, and the Central Mediterranean Carbonate Platform is proposed (abbreviated to CMCP), although the local names (such as AdCP for its NW part) should be kept to enable easier communication, and to facilitate description of local differences in platform evolution.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
One key element in the current debate analysing the Central Mediterranean evolution is the Cretaceous structure and kinematics of the present‐day oroclinal bent contact between Adria‐ and ...Europe‐derived continental units in the Dinarides, interpreted in different tectonic reconstructions as a subduction‐related thrust system or a large‐scale strike‐slip fault zone. We provide a solution to the debate by a structural and kinematic study in a key area located in central Serbia along the Europe–Adria orogenic suture of the Sava Zone. The results demonstrate that large‐scale, top‐SW, in‐ to out‐of‐sequence thrusting is the dominant mechanism that deformed the observed accretionary wedge‐trench sediments during the Late Cretaceous subduction of the Neotethys Ocean and the ensuing Adria–Europe collision. The subsequent Oligocene–Miocene extension of the Pannonian Basin was associated with opposite‐sense rotations of different Sava Zone segments, which created the observed ~80° oroclinal bending.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
One of the Mediterranean hotspots for extreme precipitation is the coastal mountainous eastern Adriatic and Dinaric Alps regions, which are often affected by heavy precipitation events (HPEs) that ...can cause severe damage. Representing these events at different time scales and projecting their future evolution using regional climate models (RCMs) remains a key modelling challenge. This study evaluates the impact of model configuration on the representation of extreme daily precipitation in an RCM at climatological (1979–2012) and event scales (HPEs). Additionally, the impact of the spectral nudging (SN) technique is analysed. We compare two CNRM‐ALADIN model configurations, and perform several sensitivity tests on specific parameters within a configuration. All simulations are driven by the ERA‐Interim re‐analysis over the Med‐CORDEX domain at 0.11° horizontal resolution. On all examined time scales, model configuration shows a considerable impact on the mean and extreme daily precipitation. The new physical parameterizations of moist processes show improvement at the climatological (precipitation intensity, extreme precipitation and frequency of light precipitation) and event (the occurrence, spatial pattern and structure of HPEs) scales. Extreme precipitation shows limited sensitivity to specific parameters and is highly dependent on HPE. The use of SN improves the temporal variability at climatological scales and the location and occurrence of HPEs. We conclude that extreme precipitation representation in CNRM‐ALADIN is more sensitive to change in the model configuration, particularly in the physical parameterizations, than to the application of SN. This study shows that the development and advancement of physical parameterizations can improve the model representation of extreme precipitation at several time scales and can therefore be considered as a means to reduce uncertainties in future climate projections.
Regional climate model configuration substantially impacts the representation of extreme precipitation, especially the physical parameterizations of moist processes. Their development and advancement improve (a) the precipitation intensity, extreme precipitation and frequency of light precipitation at climatological scale, and (b) the occurrence, spatial pattern and structure of heavy precipitation at event temporal scale. The indicated can reduce the uncertainties and build confidence in future regional climate model projections.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Studying orogens-basins interaction requires a multi-scale approach that combines multi-methodological field studies with basin-wide observations and integration with the dynamics of the lithosphere, ...the evolution of sedimentary sequences, kinematics of neighbouring mountain chains and fluid-rock interaction processes. This special issue developed out of the Sedimentary Basins Workshop (Task Force VI) of the International Lithosphere Program that took place at IFP Energies Nouvelles, France, in November 2021. It comprises 14 contributions that focus on the interactions between deep and shallow tectonic and sedimentary dynamics with fluid-flow and fluid rock interaction processes. Findings are based on field observations and associated laboratory methodologies, together with numerical modelling, that allow analysis across varied temporal and spatial scales for some of the world's best available analogues. These analogues include the orogenic systems of the Pannonian - Carpathians - Alps - Dinarides, the Pyrenees, the Mediterranean region, the Precaspian Basin and the Tibetan Plateau amongst other areas. The associated multi-scale processes that are addressed are of major societal importance, in terms of geohazards (e.g., earthquakes), geo-resources (e.g., geothermal energy, groundwater) and environmental / climatic changes (e.g., dynamic topography). Investigation of these processes in such natural laboratories and through the various applied multi-disciplinary approaches improves our understanding of the dynamic evolution of sedimentary basins and guides the future sustainable exploitation of geo-resources in the context of climate change mitigation. Throughout this special issue, fluids and their interaction with host-rocks are highlighted because most of the future usages of the subsurface will involve injecting fluids and gases underground (e.g., geothermal energy, hydrogen, or CO2 storage), and the dynamics and impacts of these applications still need to be properly understood.
•Interacting processes of orogens, basins and fluid rock interactions.•Coupling of deep and near-surface processes.•Coupling of multi-scale tectonics and sedimentary basins processes.•Multi-scale characterization of fluid-flow and fluid-rock interactions.•Predicting geohazards, geo-resources and climate change.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract
Contractional deformation structures at the front of transpressional orogens display complex three‐dimensional geometries deviating from the interpretative templates commonly applied in ...thrust belts. Accordingly, detailed constraints on deformation patterns and associated paleofluid circulation are desirable, especially for fracture geometry and permeability predictive purposes. The Pag anticline, which is located in the Dinaric fold and thrust belt, provides an appropriate field site for studying fold‐ and fault‐related deformation structures in a transpressive setting. We performed a multiscale structural analysis together with petrographic and stable isotope characterization of the deformation‐related calcite cements. Structural mapping suggests that the Pag anticline is a detachment fold developed mainly by buckling, since large‐scale thrust faults are absent. Fold tightening in a transpressive setting produced a complex deformational structure including two sets of N‐S right‐lateral and E‐W left‐lateral late‐stage strike‐slip fault sets trending oblique to the NW‐SE fold axis. The pre‐folding deformation pattern includes incipient normal faults likely related to the forebulge stage, veins and stylolites coherent with NE‐SW layer parallel shortening contraction in a strike‐slip regime, and metric to decametric scale conjugate thrusts coherent with layer parallel shortening in a compressive regime. Buckle folding preceded propagation of a series of accommodation structures during fold tightening. Petrographic and isotopic data indicate meteoric alteration of the Cretaceous platform carbonates in the prefolding stage, likely due to forebulge subaerial exposure. Layer parallel shortening and early syn‐folding veins involved formational fluids resulting from mixed marine and meteoric fluids during folding at shallow burial conditions. Eventually, meteoric fluid infiltrated again along strike‐slip faults, acting as cross‐formational conduits in the postfolding stage.
Key Points
Buckle fold with high geometrical complexity induced by overstepping forethrusts and backthrusts
Transition from compressional to transpressional stress regime during buckle folding
Paleofluid circulation switches from closed to open during fold tightening and strike‐slip faulting
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The Inner Dinarides, a part of the Alpine-Dinaride mountain chain in south-eastern Europe, are known for extended ophiolite-derived ultramafic massifs. The sampled rocks from the metamorphic sole of ...such a massif, the Jurassic Krivaja-Konjuh ultramafic massif in central Bosnia and Herzegovina, are mainly garnet amphibolites, with large grains of pyrope-almandine garnet commonly surrounded by kelyphite coronae, and pargasite amphibolites. The bulk-rock geochemistry points to mantle peridotite as the protolith for pargasite amphibolite and N-MORB for garnet amphibolite. Pressure-temperature (P-T) pseudosections were constructed in the MnNCKFMASHTO system and contoured by isopleths for the modal and chemical composition of minerals. On this basis, a counterclockwise P-T path with maximum P-T conditions of 1.2 GPa and 960 °C was deduced for pargasite amphibolite as a bottom part of an overriding plate. This part was cooled by subducting oceanic crust. In addition, the Jurassic intra-oceanic subduction enabled infiltration of hydrous fluid necessary to form the pargasite amphibolites. A clockwise P-T path with maximum pressure conditions at ca. 2.1 GPa (ca. 65–70 km depth) and temperatures of 810 °C was reconstructed for garnet amphibolite from an upper part of the subducting plate which was exhumed in a subduction channel and came in contact with the pargasite amphibolite. Thus, these amphibolites formed before they were involved in a metamorphic sole at the interface between continental crust and obducting ophiolite.
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•Pargasite amphibolite (mantle peridotite protolith) originates from a bottom part of an overriding plate.•Garnet amphibolite (N-MORB protolith) originates from an upper part of a subducting plate.•Pargasite amphibolite reached max. P = 1.2 GPa and T = 960 °C during CCW P-T path.•Garnet amphibolite reached max. P = 2.1 GPa and T = 810 °C during CW P-T path.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This paper presents palaeomagnetic results from the Miocene offshore Pag and the twin onshore (Drniš–Sinj) basins. Earlier magnetostratigraphic results were published from both basins, which ...documented that the lake sediments were good targets for palaeomagnetism. From the Pag basin, we sampled the oldest and youngest segments of the 1200m long Crnika section and obtained statistically different palaeomagnetic directions from the two parts. During a repeated visit to the section it was revealed that modern gravity-driven creeping can account for this, i.e. the results from the Pag basin should be rejected from regional tectonic interpretation.
The overall-mean palaeomagnetic direction for the Drniš–Sinj basin has excellent statistical parameters, its high quality is further supported by positive regional fold/tilt and reversal tests, based on seven geographically distributed localities. The results suggests 13–20° CCW rotation with respect to Africa and 21–27° with respect to stable Europe, during the last 15 million years. As the External Dinarides are the loci of a complicated network of Miocene and even younger tectonic zones, we cannot export the observed rotation for the whole unit, but consider our results as one step in obtaining robust kinematic constraints for the post-Oligocene tectonic history of the External Dinarides.
•Results from the Pag basin cannot be interpreted in terms of regional tectonics.•Small but significant CCW rotation affected the Drnis–Sinj basins, after 15Ma.•Robust kinematic constraints should be based on geographically distributed localities.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
A correlation of tectonic units of the Alpine-Carpathian-Dinaridic system of orogens, including the substrate of the Pannonian and Transylvanian basins, is presented in the form of a map. Combined ...with a series of crustal-scale cross sections this correlation of tectonic units yields a clearer picture of the three-dimensional architecture of this system of orogens that owes its considerable complexity to multiple overprinting of earlier by younger deformations.
The synthesis advanced here indicates that none of the branches of the Alpine Tethys and Neotethys extended eastward into the Dobrogea Orogen. Instead, the main branch of the Alpine Tethys linked up with the Meliata-Maliac-Vardar branch of the Neotethys into the area of the present-day Inner Dinarides. More easterly and subsidiary branches of the Alpine Tethys separated Tisza completely, and Dacia partially, from the European continent. Remnants of the Triassic parts of Neotethys (Meliata-Maliac) are preserved only as ophiolitic mélanges present below obducted Jurassic Neotethyan (Vardar) ophiolites. The opening of the Alpine Tethys was largely contemporaneous with the Latest Jurassic to Early Cretaceous obduction of parts of the Jurassic Vardar ophiolites. Closure of the Meliata-Maliac Ocean in the Alps and West Carpathians led to Cretaceous-age orogeny associated with an eclogitic overprint of the adjacent continental margin. The Triassic Meliata-Maliac and Jurassic Western and Eastern Vardar ophiolites were derived from one single branch of Neotethys: the Meliata-Maliac-Vardar Ocean. Complex geometries resulting from out-of-sequence thrusting during Cretaceous and Cenozoic orogenic phases underlay a variety of multi-ocean hypotheses, that were advanced in the literature and that we regard as incompatible with the field evidence.
The present-day configuration of tectonic units suggests that a former connection between ophiolitic units in West Carpathians and Dinarides was disrupted by substantial Miocene-age dislocations along the Mid-Hungarian Fault Zone, hiding a former lateral change in subduction polarity between West Carpathians and Dinarides. The SW-facing Dinaridic Orogen, mainly structured in Cretaceous and Palaeogene times, was juxtaposed with the Tisza and Dacia Mega-Units along a NW-dipping suture (Sava Zone) in latest Cretaceous to Palaeogene times. The Dacia Mega-Unit (East and South Carpathian Orogen, including the Carpatho-Balkan Orogen and the Biharia nappe system of the Apuseni Mountains), was essentially consolidated by E-facing nappe stacking during an Early Cretaceous orogeny, while the adjacent Tisza Mega-Unit formed by NW-directed thrusting (in present-day coordinates) in Late Cretaceous times. The polyphase and multi-directional Cretaceous to Neogene deformation history of the Dinarides was preceded by the obduction of Vardar ophiolites onto to the Adriatic margin (Western Vardar Ophiolitic Unit) and parts of the European margin (Eastern Vardar Ophiolitic Unit) during Late Jurassic to Early Cretaceous times.
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FZAB, GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UL, UM, UPUK, VKSCE, ZAGLJ
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