The paper presents the interpretation of magnetotelluric measurements along the SW–NE profile near Stará Ľubovňa (Northern Slovakia). The profile passes through the Outer Carpathian Flysch Belt, ...Klippen Belt and ends in the Inner Western Carpathians Paleogene NW from Ružbachy horst structure. The interpretation of the older measurements from profile Mt4 was utilized and, moreover, the 3-D geoelectrical model of studied region was constructed. The magnetotelluric data interpretations verified the northern inclination of Flysch belt structures and their smaller thickness out of Klippen Belt in direction to the Carpathian electrical conductivity zone axis. We consider this as a consequence of the flower structure—more precisely the southern branch of the suture zone related to mentioned conductivity zone. Northerly from this zone the thickness of the Outer Carpathian Flysch Belt increases and the structures have inclination to the south, i.e. to the subduction zone. The contact of Flysch Belt with Klippen Belt has a fault character and it is subvertical, slightly inclined to the North. The southern boundary between Klippen Belt and Inner Western Carpathians has also fault character and is very steep. We detect the continuation of the Ružbachy horst to the NE in the basement of Inner Western Carpathian Paleogene. The structural discordance between this horst and Klippen Belt direction is a result of younger tectonic processes. According to our results the depth distribution of the pre-Tertiary basement below the Inner Western Carpathian units is non-uniform; the basement is broken to a number of partial blocks—horsts and grabens.
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•DoD models allowed to determine that landslides remaining in contact with stream channels remain active all the time.•Colluvia are removed from the toe and foot of a landslide in ...periods between floods, which makes these landforms active by setting them in motion at the bottom first, which propagates to the top.•Colluvia are activated within the entire landslide during both major and minor floods starting from the bottom and propagating to the top or through movement propagating in both said directions: top-to-bottom and bottom-to-top.
The paper deals with the problem of the impact of river erosion on the activity level and type of colluvial movement within landslides in two study regions (Foothills and Beskidy Mts.) in the Polish Outer Carpathians. The principal goal of the study was to investigate how landslides that remain in contact with river channels function and to identify primary colluvial movement types depending on hydrometeorological conditions. Five landslides were studied, with three of them found in the Rożnowskie Foothills and two in the Beskid Niski Mts. The research was performed using terrestrial laser scanning (TLS) in the period April 2014 to November 2017. Ten measurement series were acquired during the study period. A total of 9 DEM of Difference representations (DoDs) were produced that showed both quantitative and spatial changes in the studied landslides. It was determined, based on the DoDs produced, that landslides adjacent to river channels remained continuously active due to the influence of continuously occurring fluvial erosion, although the level of activity varied, as it depended on hydrometeorological conditions. Colluvial material was set in motion within the entire landslide during floods. The recording of spatial and quantitative changes in the body of each landslide allowed to identify two key types of colluvial movement occurring during floods: (i) movement starting at the bottom and subsequently activating parts at the top (landslides: Sękówka, Boczkówka, Żabno), (ii) motion propagating in top-to-bottom and in bottom-to-top directions (landslides: Bodaki, Leszczyny). Then again, in periods between floods, colluvial material was continuously removed from the toe of each landslide, which occurred in all the studied landslides. Colluvial material became activated during these periods through movement starting at the bottom and propagating to the top. The amount of colluvium removed by streams varied depending on hydrometeorological conditions. The colluvial material carried away from the studied landslides by streams during floods comprised 60% to 90% of the volume of material removed during the entire examined period.
The origin, migration pathways, as well as the influence of secondary processes of oil and natural gas accumulated in lower Cretaceous to lower Miocene strata of the western part of the Polish Outer ...Carpathians (between Kraków and Pilzno towns) based on results of organic geochemical analyses are investigated in this paper. Oil and thermogenic hydrocarbon gases were generated mainly from type II kerogen, and type II and III kerogen mixed in various proportions. These kerogens mainly occur in the Oligocene Menilite beds of the Silesian and Dukla nappes. Oils were generated from early to late “oil window”. Secondary cracking was recorded in oils from Dukla nappe, other secondary processes including biodegradation, water washing and evaporative fractionation were also developed to a various extent in many oils. The most biodegraded oils occur in seep S-Li, and the most extensive water washing is observed in the oil from seep S-Sa/1. The evaporative fractionation processes most significantly occur in the selected deepest parts of the multi-horizontal Biecz field. Hydrocarbon gases originated during both microbial and thermogenic processes of organic matter transformation. Natural gas has not been subjected to biodegradation processes. Carbon dioxide is derived from both microbial and thermogenic decomposition processes of organic matter and was generated together with hydrocarbon gases.
The deposit Gemerská Poloma is located in the Gemeric Superunit of the Western Carpathians and it is currently mined for talc. Talc formed by metasomatic replacement of magnesite, together with ...dolomite, quartz, pyrite, and accessory minerals. Leachates of dolomite samples in 2.5 M acetic acid yield a SmNd isochron age of 271 ± 7 Ma. This age coincides with the previously published ages of the underlying, evolved granitic rocks (from 265 ± 17 to 257 ± 5 Ma, U–Th–Pb on monazite) and the UPb age of uraninite (264 ± 1 Ma) interpreted to form from fluids expelled during granite crystallization. The relationship of metasomatism and the granites is further supported by: (i) increased Li and F concentrations in the leachates from dolomite (when compared to the primary magnesite); (ii) increased total REE concentrations in dolomite (compared to magnesite) and even presence of individual REE minerals (bastnäsite) in the ore body, (iii) chondritic Y/Ho ratios, compatible with a magmatic source; (iv) the presence of skarn bodies directly above the magnesite-talc ore deposit; and (v) previously inferred low pressure of talc metasomatism, typical for contact metamorphism in shallow crustal levels. The positive europium anomalies argue for the metasomatism by the action of high-temperature (> 250 °C) hydrothermal fluids that progressively cooled below 250 °C. Thus, the observed talc metasomatism was triggered by the intrusion of the Permian granitic rocks. The Alpine processes tectonically modified the ore body, caused recrystallization and folding of the pre-existing talc and formation of new talc, and obliterated much of the evidence of the earlier processes.
•Talc metasomatism of a magnesite body resulted from an interaction with a granite intrusion.•Sm–Nd radiometric dating on dolomite constrained the timing of talc metasomatism.•Dating of hydrothermal carbonates by the NdSm method yields geologically reasonable and precise ages.
The recent launch of national-scale LiDAR-derived topographic data provides an opportunity for (re)evaluating the geomorphic imprint of landslides in forested mountains. A LiDAR-based inventory of ...deep-seated landslides (DSLs) in the highest part of Czech Outer Western Carpathians (Moravskoslezské Beskydy Mts.) reveals that nearly 20% of the territory is affected by ancient DSLs. Rather than the topography itself, we show that the geological characteristics of flysch rocks control the density, scaling relationships and morphometry of DSLs. They reveal a strong tendency to clustering in areas with favourable structural conditions, such as cataclinal slopes of individual monoclinal ridges formed by thick-bedded sandstones. In comparison with high-mountain areas and regions dominated by weaker lithology (e.g., claystone-dominated flysch), sandstone-dominated monoclinal structure of the Moravskoslezské Beskydy Mts. features predominantly short-travelled DSLs that are arrested on slopes and thus reveal a higher slope gradient than non-landslide terrain. Finally, we propose a conceptual model for the evolution of DSLs on monoclinal flysch morphostructures, particularly where coherent sandstone caps overlie weak claystone/siltstone-dominated flysch. In these conditions, we distinguish between “low” and “high” monoclinal ridges, where the former is capped by relatively thin sandstones overlying claystone formations and sandstones predominate in the structure of the latter. We show that the density of DSLs on the cataclinal/dip slopes is similar on both types of monoclinal ridges, but that major differences exist in the evolution of anaclinal/escarpment slopes. Here, low monoclinal ridges are highly affected by DSLs, but escarpments of high monoclinal ridges are nearly devoid of any DSLs.
•First regional-scale landslide inventory in the Czech Republic based on newly launched LiDAR-derived topography.•Surprisingly high area (~20%) of deep-seated landslides in the medium-high forested flysch mountain range.•Geological peculiarities of different flysch formations affect the scaling relationships and morphometry of deep-seated landslides.•Height of monoclinal ridges and ratio of thickness between rigid and weak flysch formations affect the types and distribution of deep-seated landslides.
The thin-skinned Hronic nappe system represents the structurally highest tectonic unit in the Late Cretaceous thrust-stack of the Central Western Carpathians. It mostly comprises a Permian ...volcano-sedimentary sequence and Triassic carbonate sediments which crop out in different parts of the Central Western Carpathians. We carried out a systematic paleomagnetic study on 24 Permian and 20 Triassic localities geographically distributed over 300 km in W-E direction. Several samples from each locality were drilled and oriented in-situ and specimens cut from them subjected to standard paleomagnetic and magnetic mineralogy experiments. The results were evaluated using principal component analysis, statistical evaluation of the characteristic remanences, and applying inclination-only and tilt tests. We documented the pre-tilting age of remanences for the majority of both the Permian and Triassic age groups. However, the latter was interpreted as remagnetized during the Cretaceous Normal Super-Chron in the course of nappe stacking between 90−80 Ma. The Permian group is exhibiting about 70°, the Triassic about 34° clockwise vertical axis rotations with respect to the present north. There is no indication in our data set for oroclinal bending of the Hronic Unit. We interpret the difference in clockwise rotations (about 36°) between Permian and 90−80 Ma as a clockwise block rotation taking place during major extensional and/or compressive events between stable Europe and Africa. Taking into consideration the well-documented counterclockwise rotation observed for the overstep sequences in the Central Western Carpathians and in the Pieniny Klippen Belt, the remagnetization of the Triassic sediments was closely followed by about 94° clockwise rotation. Research in progress will serve to decide if this large clockwise rotation involved the whole Central Carpathian nappe stack or part of this was due to the thin-skinned nappe emplacement of the Hronic Unit.
The Gemeric and Veporic Superunits of the Western Carpathians correlate to the Lower and Middle Austroalpine tectonic units (nappes) of the Eastern Alps. The Gemeric Superunit is characterized by ...small exposures of rare-metal granites, and their ages impact understanding its tectonic history and how this portion of the Carpathians relates to other Permian age granites exposed throughout Europe and the Western Mediterranean. Here we present new Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) and Secondary Ion Mass Spectrometry (SIMS) zircon U--Pb ages from northern (Hnilec) and southern Gemeric granite exposures (Betliar, Elisabeth Mine, Poproč) and one from the Veporic Superunit (Klenovec). Geochemical analyses of Betliar and Klenovec samples indicate they are highly differentiated and fractionated from a clay-rich source, consistent with published reports for these granites. Zircon saturation temperatures average 733 ± 27 °C (Betliar) and 756 ± 61 °C (Klenovec). Most Gemeric granitic zircons are Permian (n = 231 spots), with some inherited zircons giving Middle Ordovician to Late Silurian (n = 26), and some Triassic (n = 6) U--Pb ages. The dominant Permian U--Pb yield crystallization ages of at 264 Ma for the Gemeric granite and 265 Ma for the Veporic Superunit's Klenovec granite (n = 26). Klenovec zircons typically show distinct yellow rims in cathodoluminescence, characteristic of lower temperature overprint (<600 °C). These granite zircon ages overlap those from the radiolarite-bearing metasediments from the Meliata Ocean exposed in the Dobšiná region (263.9 ± 2.7 Ma, LA-ICP-MS, ±1σ). The detrital zircon U--Pb ages thus imply a possible beginning of sedimentation in the Meliata Ocean as early as the mid-Permian. The genesis of the Gemeric and the Klenovec granites is related to post-collisional extension. These data link the Western Carpathians to a regional widespread occurrence of Permian magmatism in the European Variscan and Western Mediterranean realms, consistent with regional magmatic re-equilibration of the Moho. This scenario likely occurred in response to a thermal surge that involved significant decompression and extension, lower crustal melting, upward displacement of the Moho, and delamination of the mantle-lithosphere that contributed substantially towards Variscan crustal thinning.
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•The Western Carpathian Gemeric granites are mid-Permian (~264 Ma).•The adjacent Veporic Superunit Klenovec granite is similar in age (~265 Ma).•Zircons show the onset of Meliata Ocean sedimentation since mid-Permian (~264 Ma).•Results indicate widespread extensional-related Permian magmatism across Europe.
Zircon petrochronology from amphibolites and retrogressed eclogites from the basement of the Western Tatra Mountains (Central Western Carpathians) reveals a complex rock evolution. An island-arc ...related basaltic amphibolite from Žiarska Valley shows three distinct zircon forming events: igneous zircon growth at ca. 498 Ma (Middle/Late Cambrian) and two phases of amphibolite-facies metamorphism at ca. 470 Ma (Early Ordovician) and at ca. 344 Ma (Early Carboniferous). A retrogressed eclogite from Baranèc Mountain records two zircon forming events: metamorphic zircon growth under eclogite-facies conditions at ca. 367 Ma (Late Devonian) and amphibolite-facies metamorphism at ca. 349 Ma (Early Carboniferous). These data contribute towards understanding and correlating major tectonothermal events that shaped the eastern margin of Gondwana in the Early Palaeozoic and its subsequent Variscan evolution. The metabasites record vestiges of two completely independent oceanic domains preserved within the Central Western Carpathians: (1) An Ediacaran to Cambrian oceanic arc related to the proto-Rheic - Qaidam oceans and metamorphosed to amphibolite-facies in the Early Ordovician subduction of the proto-Rheic - Qaidam arc during the Cenerian orogeny (ca. 470 Ma) and (2) Late Devonian oceanic crust related to a back-arc basin (Pernek-type), formed by the opening of the Paleotethys and metamorphosed to eclogite-facies during Devonian subduction (ca. 367 Ma). The common Variscan and later evolution of these oceanic remnants commenced with amphibolite-facies metamorphic overprinting in the Early Carboniferous (amphibolite: ca. 344 Ma; retrogressed eclogite: ca. 349 Ma) related to an Early Variscan consolidation and the formation of Pangea. None of the investigated rocks of the Central Western Carpathians show any evidence of being chronologically or palaeogeographically related to the Rheic Ocean, therefore any prolongation of the Rheic suture from the Sudetes into the Alpine-Carpathian realm is highly problematic. Instead, the Southern and Central Alpine Cenerian orogeny can be traced into the Central Western Carpathians.
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•W Tatra amphibolites are remnants of the Cambrian proto-Rheic - Qaidam Ocean.•W Tatra meta-eclogites protoliths are related to the opening of the Paleotethys.•Early Ordovician Cenerian Orogeny extends into the Central Western Carpathians.
In the Carpathian–Pannonian region in Neogene times, westward-dipping subduction in a land-locked basin caused collision of two lithospheric blocks (Alcapa and Tisia) with the southeastern border of ...the European plate. Calc-alkaline and alkaline magmatism was closely related to subduction, rollback, collision and extension. From the spatial distribution of the magmatic activity, four segments can be defined: Western Segment (magmatism occurring on the Alcapa block), Central Segment (magmatism occurring on both Alcapa and the Tisia blocks), South-Eastern Segment and Interior Segment (both on the Tisia block).
Most calc-alkaline magmatism in the region resulted from melting of a heterogeneous asthenospheric mantle source modified by addition of fluids and sediment. Assimilation and fractionation processes at shallow crustal levels occurred in most of the segments, strongly masking the deeper source processes. Long-term subduction, rollback and/or delamination led to contamination of the asthenosphere beneath the Western Segment. Here, large-volume partial melts of the contaminated mantle caused underplating and crustal anatexis, leading to mixing of mantle-derived calc-alkaline magmas with crustal melts. In the Central Segment, calc-alkaline magmas were formed by subduction and rollback, followed by back-arc extension and slab breakoff. A variable mantle source is indicated in the back-arc setting and larger amount of fluid-induced metasomatism, source enrichment and assimilation nearer to the trench. In the Interior Segment, evolution from typical calc-alkaline magmas to adakite-like ones was related to extension due to fast rotations and transtensional tectonics. Here, calc-alkaline magmas formed by decompression melting of a heterogeneous crust–mantle lithosphere, while adakite-like melts resulted from fliud-dominated melting of the lithosphere. Along the South-Eastern Segment, slab breakoff was responsible for the generation of typical calc-alkaline magmas, but in the extreme south of the segment, shallow level tearing of the slab followed breakoff. Strike–slip tectonics allowed the rise of hot asthenosphere and generation of adakite-like magmas, via slab-melting, along the torn edge of the East European Plate. Alkalic basaltic volcanism with an OIB-like asthenosphere source followed the calc-alkaline stage (Western Segment), or was contemporaneous with it (South-Eastern and Interior Segments) mainly in response to local extensional tectonics.
The occurrence of amber in the Central Carpathian Paleogene Basin is reported here for the first time. The amber has been analyzed by means of optical microscopic methods, infrared spectroscopy, gas ...chromatography/mass spectrometry, and pyrolysis-gas chromatography/mass spectrometry to understand the amber composition, origin, taphonomy, alteration, and diagenesis. Organic petrographic and reflectance analyses of organic matter from amber-bearing sediment was carried out to get information about paleoenvironment and maturity of sedimentary rock.
Analyses confirmed polylabdane structure associated with Class Ib -type of amber and its possible origin from the conifer family Araucariaceae. It is characterized by a high degree of maturity, where both temperature and exogenic processes have participated in its conversion. Heterogeneity of reflectance values in the resinite suggests that amber was not redeposited from an older and more mature sedimentary unit. The discrepancy between the maturity of the amber and amber-bearing sedimentary rock, along with abundant char and inertinite macerals indicates a probability of thermal alteration of the amber under the influence of heat from a wildfire and increased maturity occurring before its ultimate burial in a deep-sea environment. The assemblage of terrigenous macerals and numerous char and inertinite particles which were found in amber-bearing sediment, as well as in the amber crust, suggest forest-swamp type vegetation affected by wildfires. The presence of amber and predominantly terrigenous organic matter, besides mud rip-up clasts derived from freshwater sediments in deep-marine deposits, indicates a direct connection of terrestrial environments to the deep-water depositional system.
•Amber from the Oligocene deep-water deposits of the Central Western Carpathians.•Composition, origin, taphonomy, alteration, and diagenesis of amber.•Amber affected by wildfire.•The maturity of amber versus thermal maturity of the host sediment.•Wildfire temperatures deduced from the reflectance of macerals.
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