Outer Western Carpathians Research Articles

Fungal genetic biodiversity and metabolic activity as an indicator of potential biological weathering and soil formation – Case study of towards a better understanding of Earth system dynamics

Terrestrial plants act as ecosystem engineers modifying the flow of energy and matter and creating new habitats for other organisms. This vital concept also encompasses plants' effects on landforms and soils, crucial components of forested landscapes worldwide. In the present study, we investigate how trees through their roots and symbiotic organisms influence soil-weathering processes. The aim of the study was to answer one of the big questions in Earth sciences: how do biological agents, including fungi, acting at the critical interface between the biosphere and the abiotic environment, shape soil and landscape evolution? Within the present study we ask what is the level of fungal activity within root systems of trees and how can it influence biological weathering. The area of interest is in the Poprad River gorge in the southern part of the Sącz Beskidy Mountains, the Outer Western Carpathians. We applied the following analyses: 1) determination of the structural diversity of fungi (ITS1) and 2) assessment of the metabolic profile of soils (Biolog FFPlates). The highest average number of classified genera were fungi which simultaneously carried out pathotrophic, saprotrophic and symbiotrophic functions. Boletales, Agaricales, Cantharellales and Archaeorhizomycetales were the most abundant orders, but in one sample we also found a particularly high proportion of the order Mortierellales. The order Boletales and its family Boletaceae were significantly enriched in rock crack samples, whereas the highest number of differentially abundant taxa was observed in reference samples. The most frequently utilised substrates by fungi were: glycyl-L-glutamic acids, L-ornithine, L-phenylalanine, L-proline, D-galacturonic acid, fumaric acids, D-saccharic acids, succinic acids and N-acetyl-D-glucosamine. Our study demonstrates that the fungal community in the root zone is geochemically active and the organic acids secreted by plant roots in oligotrophic conditions and nutrient limitations significantly affect soil weathering.

Relief-induced feedback mechanisms controlling local podzolization occurrence on flysch slopes – Examples from Outer Western Carpathians (southern Poland)

Podzolization is one soil-forming process that at a landscape scale is sensitive to relief-related factors. In the areas where leached and coarse-textured parent material together with humid climate and forest or heath vegetation favour development of Podzols the intensity and advancement of this process are connected with landscape position, inclination, topography and related water table effects. Flysch bedrock, which affects the slope deposits in many mountain regions due to high content of clay, Fe and alkaline compounds in its major part is considered to be a parent material unfavourable for podzolization. On the other hand, podzolization occur locally in soils developed from flysch. The main objective of this study was to determine the role of relief in conditioning podzolization occurrence on flysch slopes in the Outer Western Carpathians in southern Poland. Soils located in two slope transects were studied in terms of weathering rates, aeolian silt admixture, soil properties and soil-forming processes differentiation. Furthermore, at selected sites in situ soil moisture was measured, while the slopes with transects were subject to geomorphometric analysis. Podzols development was evidenced at the uppermost slopes and – locally – at middle slopes. Two feedback mechanisms controlling podzolization occurrence in a small scale were proposed. The first positive feedback loop explained crossing the pedogenic threshold of podzolization via relatively higher soil moisture that lead to slower organic matter turnover and more advanced weathering. This mechanism, in turn, triggered podzolization. The second negative feedback mechanism was responsible for suppression of Podzols development at steep slopes. On the one hand, it was related with active geomorphic processes that caused soil rejuvenation, and with relatively lower soil moisture conditioned by less effective precipitation per unit area on the other. Both resulted in inhibited weathering and precluded podzolization occurrence.

Příspěvek k poznání exotických hornin flyšového pásma Západních Karpat: chloritoidová břidlice z Nového dvora u Kvasic (Chřiby)

New occurrence of pebbles of chloritoid schists, found in Eocene-to-Oligocene conglomerates of the Zlín Formation, Rača Unit, Magura Flysch, Outer Western Carpathians, Czech Republic, is characterized in this contribution. The rock has very simple mineral composition, including chloritoid, quartz, white mica and trace amount of apatite, rutile, and monazite. Chloritoid contains only very small proportions of magnesiochloritoid (7 - 11 mol. %) and ottrelite (up to 0.4 mol. %) components. The composition of white mica corresponds to muscovite and illite. The significant differences in mineral assemblages of rocks as well as in chemical composition of chloritoid and white mica usually appeared during comparison with those of similar rock types occurring in potential source areas in the Czech Republic, Slovakia, and Austria. The best comparable chemical composition showed only chloritoid in chloritoid schist from Bělá in the Hrubý Jeseník Mts., Silesicum, Czech Republic.

Hydrochemické vlastnosti zdrojů termálních minerálních vod v oblasti Pasohlávky – Laa an der Thaya

The South Moravian region of Pasohlávky and the Lower Austrian town of Laa an der Thaya belongs to the areas of intensive use of thermal mineral water for recreational and balneological purposes. Thermal mineral water is extracted from a deep-seated Jurassic aquifer, mainly composed of carbonates. These carbonates overlie the crystalline bedrock, which is dipping towards the southeast below the Outer Western Carpathians. Due to this trend, there are two developments of the Jurassic sediments that differ in their lithological composition and are vertically separated by the Mušov transition zone. To the northwest from this zone, there is a shallower carbonate development and in the southeast, there is a deeper development which is composed of permeable carbonates together with impermeable marls. The Neogene sediments of Carpathian foredeep are deposited on the top of the Jurassic carbonate structure. Thermal mineral water is exploited by two hydrogeological wells – Muš-3G (Pasohlávky, 1 455 m deep) and Laa Th N1 (Laa an der Thaya, 1 448 m deep) situated in the shallower carbonate part of the Jurassic aquifer. The aim of this study, that summarizes the important partial outputs of the cross-border project Interreg HTPO (Hydrothermal Potential of the Area, ATCZ167), is to specify and clarify the origin, genesis and the processes of water formation based on the hydrochemical evaluation of thermal mineral water. For this purpose, both the final reports of studied wells and especially results from newly performed analyses of stable isotopes of hydrogen δ2H and oxygen δ18O were used. The δ18O and δ2H values of water samples from the Muš-3G well varies from –12,77 ‰ to –12,03 ‰ and from –92,23 ‰ to –88,05 ‰, respectively, while water samples from the Laa Th N1 well are isotopically heavier with δ18O values ranging from –7,04 ‰ to –6,31 ‰ and with δ2H values ranging from –51,04 ‰ to –49,33 ‰. In the Pasohlávky region we suppose it is an isotopically depleted water that has infiltrated in the cold climatic period (glacial). Evaluation of the chemical composition revealed that although the thermal waters from both areas of the hydrogeological structure are of the same Na–Cl type, their total mineralization differs significantly. Lower total mineralization in the Pasohlávky area (approx. 2,2 g/L) is also associated with higher relative concentrations of bicarbonate ions (HCO3–) and atmogenic nitrogen, typically bound to infiltrated meteoric waters. The thermal water in this area is mostly of meteoric origin, mixed with primary marinogenic water. In the Laa an der Thaya region, there is water with higher total mineralization (approx. 11 g/L) and lower relative concentrations of HCO3–, which together with the results of isotope analyses indicates a higher content of primary seawater. The marinogenic origin of waters also confirms the presence of bromides and iodides. The process of mixing primary marine waters with infiltrated meteoric waters significantly contributes to the chemical composition of the studied waters in both areas, while the original marinogenic water type of Na-Cl is preserved.

Maximální rozšíření pleistocenního ledovcového štítu ve Vnějších Západních Karpatech a Východních Sudetech – současné znalosti a nový důkaz

A single find of erratic Baltic flint in the Slezské Beskydy Mts. represents a rare evidence of glaciation in the area. The find originates from fluvial deposits of Weichselian valley terrace of the Hluchová Stream, tributary of the Olza River. The erratic was reworked from Elsterian sediments deposited by the Scandinavian Ice Sheet in a very marginal position near its maximum extent in Outer Western Carpathians. Based on morphological analysis, the surface of the erratic was abraded by wave action in the source area on the Baltic shore and subsequently by glacial and (glacio)fluvial transport. Position of the find proves the glaciation of the Olza River valley by a greater ice lobe, than previously assumed.

Morfostrukturní doklady ponásunového porušení Pavlovských vrchů, Vnější Západní Karpaty

The article presents geomorphological and structural evidences of post-thrust limestone brittle deformation in the area of Pavlov Hills on the westernmost margin of the Outer Western Carpathians, Czech Republic. Airborne LiDAR-derived digital terrain model with 1 m resolution was used for this analysis, as well as aerial photographs and fieldwork. Combining these methods, we document a distinct N-S directed fault zone that intersects or delineates the majority of the Pavlov Hills Jurassic limestone nappe outliers. Data revealed an almost continuous fault zone of the north-south direction, which ranges from Horní Věstonice in the North, to Mikulov in the South, and extends further south to Austria. The thrusted Jurassic limestone bodies are cut by the fault zone, which tectonically crushed the limestone in its core and cores of the secondary fault branches. The map pattern of the fault zone suggests directional anastomotic branching and reattaching with the production of lenticular tectonic slices. We interpret the fault as a prominent sinistral shear zone. This is indicated by block displacement on the Svatý kopeček Hill and also by the orientation of the accompanying subvertical Riedel shears with identified horizontal lineation. The activity of the fault zone onset tightly after the nappe thrusting at the final stages of the accretion wedge formation, which is suggested from the observed sinistral kinematics. The main movement along the fault is thus most probably of a late Miocene age.

What does dendrogeomorphology tell us about past river discharges: A comparative study of confined and unconfined fluvial systems

Recently, dendrogeomorphic methods have been increasingly used for the dating past-flood events, and tree-ring-based approaches are generally considered valuable tools in palaeohydrology. Several limitations of the approach are known, but their effects on the resulting chronologies have not been assessed or quantified. Thus, this study attempts to critically evaluate and quantify the effectiveness of dendrogeomorphology in past-flood analysis. The tree-ring-based methods were tested on two long-term monitored, contrasting catchments in a region in the Outer Western Carpathians. In total, 101 sampled trees provided evidence of 126 growth disturbances, enabling the reconstruction of seven flood events approximately during the last 30 years in each catchment.After the comparison of monitored discharges with tree-ring records, standard dendrogeomorphic indices enabled the detection of approximately half of the flood events with discharges larger than the maximal sensitivity of the approach used (minimal detected discharge corresponding to ca. Q2). Nevertheless, significant differences were identified between the two catchments. Values of dendrogeomorphic indices corresponded well to values of maximal discharges, and increasing the indices thresholds increased the proportion of detected floods in narrow mountainous catchment. In contrast, no effect on the proportion of detected flood events after indices threshold increase was detected in the case of a wide braided channel (in the second catchment). However, the indices values corresponded well to the flood volume. The differences were probably caused by the water-level behaviour in narrow and wide channels. Thus, it seems that the characteristics of channel reaches must be very carefully considered in regard to the interpretation of dendrogeomorphic results of past-flood events.

Late Glacial and Holocene palaeoenvironmental changes recorded in landslide fens deposits in the Polish Outer Western Carpathians (Southern Poland)

In the northern part of the Polish Outer Western Carpathians, the Beskid Makowski Mts., four landslides formed during the Late Glacial have been identified, so far. Within the depositional sequences (organic-mineral) of fens occurring in landslide depressions, palaeoenvironmental changes of the Late Glacial and the Holocene are recorded. The oldest of fen, started to form in the Oldest Dryas Stadial, the younger ones – in the Bølling Interstadial (two fens) and in the Older Dryas Stadial. The thickness of fen deposits varies from 1.5 m to 4.5 m. The sediments deposited in the Late Glacial represent long sequences (reaching 50–80% of the profile), whereas the Holocene deposits are reduced here due to the occurrence of long-lasting sedimentation gaps (hiatuses). The reconstruction of palaeoenvironment was carried out on the basis of pollen and lithological (loss on ignition, areometric) analyses along with more than 45 14C datings. In the Late Glacial sequences of the examined logs, mineral horizons interlaying organic deposits were affected by periodic climate warmings resulting in the permafrost melting during the Bølling and the Allerød Interstadials. In the Late Glacial deposits there are sequences (ca 0.5 m thick) deposited during the Older Dryas Stadial. The Allerød in the analyzed logs is bipartite: the lower sections (AL-1) are usually represented by peat deposition, whereas in the upper parts of the logs (AL-2) numerous minerogenic (clay, silty clay) inserts confirm the climate humidity growth (or permafrost melting) during the Gerzensee Oscillation. In the Late Glacial deposits, pollen of thermophilous trees, such as Corylus, Tilia, Quercus, Carpinus, as well as (typical for the Subboreal Phase) Abies alba and Fagus sylvatica occur, which may indicate the presence of thermophilous refugia in this part of the Carpathians. During the middle part of the Younger Dryas Stadial climate cooling, the widespread gradual increase in the delivery of allochthonous material to fens is related to permafrost melting. This process is finished by the deposition of clay and silty clay horizon at the beginning of the Holocene (Preboreal). The lack of the depositional sequences of the Boreal, Atlantic and partly the Subboreal phases in the majority of the logs is caused by the erosional removal of sediments during the climate humidity growth at the beginning of the Subboreal and the Subatlantic phases.

Three-dimensional magnetotelluric model along seismic profile 2T: An improved view on crustal structure in central Slovakia (Western Carpathians)

We present the crustal-scale geophysical model based on the magnetotelluric method focused on 3-D model¬ling of the seismic 2T profile crossing the major Western Carpathian tectonic units in central Slovakia. The results of the 3-D modelling show substantial improvement in previous 2-D models of deep crustal structure in central Slovakia, mainly of the physically distinct tectonic segments and major geo-electrical regional structures like the zone of the Carpathian Conductivity Anomaly, which indicates the occurrence of the large-scale shear zone in the contact zone of the European platform and Inner Western Carpathians. High detail geo-electrical data in 3-D magnetotelluric (MT) cross section also allowed a better interpretation of other conductive anomalies. In the final integ-rated interpretation (combination of 3-D geo-electrical model, gravity data and seismic reflectors), it is shown that frontal part of the Inner Western Carpathians plate exhibits the transpressional tectonic style of the back-thrust Outer Western Carpathians (Flysch Belt) and Pieniny Klippen Belt units over the progressing Inner Western Carpathian thrust wedge. These back-thrusts form the southern branch of the accretionary structural fan – a large-scale transpressional flower structure typical mainly but not only for oblique con-vergent regimes. The southernmost segment of the profile with high whole-crust conductivity due to a higher heat flow caused by young volcanic activity indicates partial melting in the middle and lower crust.

Manganese-rich carbonate and phosphate concretions from the Subsilesian Unit of the Outer Western Carpathians (Czech Republic): Composition and unique selenium weathering products

Manganese-rich carbonate and phosphate concretions from the Subsilesian Unit of the Outer Western Carpathians (Czech Republic): Composition and unique selenium weathering products

The Late Jurassic–Palaeogene Carbonate Platforms in the Outer Western Carpathian Tethys—A Regional Overview

The present work focuses on palaeogeographic reconstruction of shallow-water carbonate deposition in the Outer Western Carpathian Tethys. Platform deposits are preserved only as a component of turbidites and olistostromes, and reconstructions of these platforms are based on clastic material redistributed into slopes and deep basins and occurring among the Outer Carpathian nappes. Similar platforms were also present on the Tethys margins. These reconstructions were performed using the global models of plate tectonics. Several ridges covered by carbonate platforms developed in that area during the latest Jurassic–Palaeogene times. Three main shallow-water facies associations—Štramberk, Urgonian, and Lithothamnion–bryozoan—could be distinguished. The Tithonian–lowermost Cretaceous Štramberk facies is related to early, synrift–postrift stage of the development of the Silesian Domain. Facies that are diversified, narrow, shallow-water platforms, rich in corals, sponges, green algae, echinoderms, foraminifera, microencrusters, and microbes are typical of this stage. The Urgonian facies developed mainly on the south margin of the Outer Carpathian basins and is characterised by organodetritic limestones built of bivalves (including rudists), larger benthic foraminifera, crinoids, echinoids, and corals. Since the Paleocene, in all the Western Outer Carpathian sedimentary areas, Lithothamnion–bryozoan facies developed and adapted to unstable conditions. Algae–bryozoan covers originating on the siliciclastic substrate are typical of these facies. This type of deposition was preserved practically until the final stage in the evolution of the Outer Carpathian basins.

Burial and Thermal History Modeling of the Paleozoic–Mesozoic Basement in the Northern Margin of the Western Outer Carpathians (Case Study from Pilzno-40 Well, Southern Poland)

Hydrocarbon exploration under thrust belts is a challenging frontier globally. In this work, 1-D thermal maturity modeling of the Paleozoic–Mesozoic basement in the northern margin of the Western Outer Carpathians was carried out to better explain the thermal history of source rocks that influenced hydrocarbon generation. The combination of Variscan burial and post-Variscan heating due to elevated heat flow may have caused significant heating in the Paleozoic basement in the pre-Middle Jurassic period. However, the most likely combined effect of Permian-Triassic burial and Late Triassic–Early Jurassic increase of heat flow caused the reaching of maximum paleotemperature. The main phase of hydrocarbon generation in Paleozoic source rocks developed in pre-Middle Jurassic times. Therefore, generated hydrocarbons from Ordovician and Silurian source rocks were lost before reservoirs and traps were formed in the Late Mesozoic. The Miocene thermal overprint due to the Carpathian overthrust probably did not significantly change the thermal maturity of organic matter in the Paleozoic–Mesozoic strata. Thus, it can be concluded that petroleum accumulations in the Late Jurassic and Cenomanian reservoirs of the foreland were charged later, mainly by source rocks occurring within the thrustbelt, i.e., Oligocene Menilite Shales. Finally, this work shows that comprehensive mineralogical and geochemical studies are an indispensable prerequisite of any petroleum system modelling because their results could influence petroleum exploration of new oil and gas fields.

Low-topography deep-seated gravitational slope deformation: Slope instability of flysch thrust fronts (Outer Western Carpathians)

Unlike high-relief mountain areas, low-relief hilly landscapes are usually rarely affected by deep-seated gravitational slope deformations (DSGSDs). However, low-topography flysch thrust fronts can create suitable structural conditions for DSGSDs. The study area of the Kavalčanky ridge represents a relatively low-lying (<120 m of local relief) DSGSD-affected ridge situated at the thrust front in the flysch Outer Western Carpathians (Czech Republic). With the aim of revealing the main controlling factors and temporal constraints of mass-movement activity, a multidisciplinary investigation of DSGSDs was performed. Typical DSGSD landforms were mapped using high-resolution LiDAR-based mapping. Structural analysis revealed the presence of specific flysch thrust structural conditions with competent sandstone units overthrusted on a weak tectonically disrupted claystone basement. Geophysical measurement with the use of electrical resistivity tomography (ERT) and ground penetrating radar (GPR) profiling confirmed the deep reach (>50 m) of the studied DSGSD. Together with slope stability finite element modelling, geophysics suggests that the shear zone of DSGSDs is represented by one of the thrust faults, whereas lateral limits are formed by a set of conjugate strike-slip faults. Radiocarbon dating of bogs within the DSGSD body showed two phases of mass-movement activity corresponding to the Late Glacial-Holocene transition and Middle Holocene. The recent activity was excluded by dendrogeomorphic analysis. We concluded that the structural conditions involving high lithological complexity, tectonic weakening and the presence of major tectonic contacts might create conditions prone to DSGSDs even in relatively low-topography settings with mass movement activity, especially during humid and warmer Late Quaternary periods.

Legacy of Human Impact on Geomorphic Processes in Mountain Headwater Streams in the Perspective of European Cultural Landscapes

Mountain headwater streams are still somewhat on the boundary of interest regarding possible human impact on their morphology or geomorphic processes, which may be caused by our perception of mountains as islands of relatively preserved natural conditions. This paper summarizes the past and present human pressure on the headwater streams that drain the highest mountain ranges of the Outer Western Carpathians in Czechia. Anthropogenic pressure began in this region in the 16th century during a colonization of the mountains and continued by timber harvesting, timber floating, and construction of torrent control works until present. Each of these interventions produced a morphological response of the channels in relation to altered sediment or water fluxes at the whole catchment scale or within longitudinal stream profiles. Because it is highly unlikely to reach pre-settlement conditions of the channels, the management effort should be concentrated to achieve realistic restoration targets under the present socioeconomic circumstances by taking into consideration the morphodynamical specifics of mountain headwater streams.

Karst features within conglomerate bed of the Palkovice Formation, Silesian Unit of the Outer Western Carpathians

Karst features within conglomerate bed of the Palkovice Formation, Silesian Unit of the Outer Western Carpathians

Lower Cretaceous belemnites of Štramberk klippen (Czech Republic): Implications for geological history of the outer Western Carpathians

Based on thorough taxonomic work with more than 10,000 rostra from the famous Štramberk locality (Northern Moravia, Czech Republic), belemnites were classified at the generic and species levels. The following genera have been recorded within this study: Berriasibelus, Duvalia, Pseudobelus, Hibolites and Conohibolites, including 23 species. A systematic and stratigraphic framework for sedimentary history has been used for important stratigraphical, palaeobiogeographical and geological interpretations. An unusual and extremely high diversity of belemnites within the sedimentary infills in the limestone crevasses has been explained by processes of multiple belemnite rostra being reworked from older sediments. Belemnite assemblages known from other areas within the North Western Tethys were compared with our material and used for detailed stratigraphical determination. The stratigraphic distribution of the studied belemnites ranges from the ?latest Tithonian/Berriasian to Valanginian, ?Hauterivian and newly Barremian. Although the palaeogeographical position of the Štramberk block is not known, the belemnite fauna biogeographically belongs to the Mediterranean Province. Since the Hauterivian, we refer this fauna to the French–Bulgarian Subprovince. The closest similarity of the Štramberk belemnite fauna is to those from France and Bulgaria and is therefore of high palaeobiogeographic value. No Boreal and/or Subboreal influences within belemnites were observed. The belemnite occurrences have also been investigated in the bathymetric/facies context and compared to published data from various Tethyan areas.

Tracing Pre-Mesozoic Tectonic Sutures in the Crystalline Basement of the Protocarpathians: Evidence from the Exotic Blocks from Subsilesian Nappe, Outer Western Carpathians, Poland

Pre-Mesozoic exotic crystalline blocks within the Outer Carpathian flysch have potential to unravel the nature of their eroded basement source(s) and to reconstruct the Paleozoic–Precambrian history of the Protocarpathians. Strongly tectonized Campanian–Maastrichtian grey marls in the Subsilesian Nappe of the Outer Western Carpathians in Poland contain a variety of different lithology types, including granitoids and andesites. Petrological investigations coupled with zircon and apatite U-Pb dating were performed on crystalline (subvolcanic) exotic blocks from a locality in the Subsilesian Nappe. U-Pb zircon dating yields magmatic crystallization ages of c. 293 Ma for the microgranitoid and c. 310 Ma for the andesite block, with inherited zircon cores yielding Archean, Paleoproterozoic, Mesoproterozoic and Cadomian ages. Whole rock trace element and Nd isotope data imply that the melt source was composed of a significant Neoproterozoic crustal component in both the microgranite and andesite. The Late Carboniferous–Permian magmatic activity likely continues outside the Carpathian Belt and can be linked to a Late Paleozoic transtensional zone, which is a continuation of the Lubliniec–Kraków Zone that extends under the Carpathians to Moesia. This Late Paleozoic transtensional zone was probably reactivated during the Late Cretaceous under a transpressional regime within the Żegocina tectonic zone, which caused the uplift of the Subsilesian Ridge and intensive erosion.

Geological control of young orogenic mountain morphology: From geomorphological analysis to reinterpretation of geology of the Outer Western Carpathians

The paper presents a new concept of geological control of the Outer Western Carpathians (OWC) morphology. The establishment of the Carpathians' morphology dates back to the stage of evolution of sedimentary basin, when huge blocks of solidified rock massifs were gravitationally displaced into the foreland sedimentary basins, forming finally isolated hills. The altitudinal difference between the Beskidy Mts. and the Carpathian foothills is caused by the structural positions of these two segments of rock massifs within the orogenic megastructure during the compressional stage. Indeed, the tectonic elements that formed during the earliest stage of compression took (and still take) the highest structural and altitudinal position, whereas the elements incorporated into the orogen as the last have taken a lower topographic position, forming a belt of foothills. Therefore, this difference in topography is not related to rock resistance only, as was previously thought. The rotation of the Carpathian blocks during the orogenic thrusting and the formation of strike-slip fault zones parallel to the Carpathian tectonic thrusts formed a flower structure, which has played a significant role in morphology (insular character of). During the stage of secondary tectonic deformation – including the rotation of the Carpathian tectonic segments, strike-slip faulting and the radial extension and large extensional collapse of the Carpathian massifs – the principal features of the Carpathian relief as well as the main river valleys were formed. Gravitational collapse resulted in back-thrusting and the tectonic exhumation of the Carpathian massifs, which helps to explain the problem of seemingly large denudation of the Carpathian overburden of a thickness estimated at several kilometres. Chaotic complexes (synsedimentary and syntectonic mélanges), which frequently occur in the Carpathians, are very important for the Carpathian morphology and river valley development (controlled not only by faults) as well as the formation of isolated hills. Analysis of the Carpathian morphology supported by the Bouguer's gravity anomalies map, and geological data allow us to present a new hypothesis that the Carpathians were formed as a huge regional flower structure, without the participation of subduction, which has formerly been considered to play the crucial role in the formation of the Carpathian orogen.

The dendrogeomorphic spatio-temporal reconstruction of flow-like landslides activity in one of the most susceptible region of Central Europe (the Vsetínské vrchy Mts.)

Flow-like landslides are a dangerous landslide type. They often express gradual movement or seeming dormancy, but occasional reactivation can, in extreme cases, result in catastrophic events. To predict their future behaviour, knowledge of past spatio-temporal development and relationships with hydrometeorological triggers is crucial. Moreover, regional data are more robust than case studies. Dendrogeomorphic (tree-ring-based) methods are a very precise approach for reconstructing past landslide behaviour. Nevertheless, regional reconstructions are very rare, which is probably due to their time-consuming procedures. This paper presents the results of a regional tree-ring-based reconstruction of the spatio-temporal development of flow-like landslides in a selected region in the Outer Western Carpathians. Six selected landslides were studied via analysis of 614 increment cores that came from 307 disturbed trees. The reconstruction provided data for approximately 70 individual landslide reactivation phases that were distributed in 44 event years. Events with regional extension (at least half of the studied landslides were active) were detected in six years (1940, 1941, 1953, 1961, 1985, and 1997). Periods of increased (1950s, 1990s) as well as decreased (1940s, 1970s, 2010s) landslide activity were reconstructed. The use of tree-ring data enabled the construction of landslide probability maps. Based on this analysis, all studied landslides exhibit extremely high probabilities of reactivation during a temporal horizon of 100 years, but even over shorter periods (5 and 20 years), their probability of reactivation is very high. Finally, analysis of meteorological triggers suggests the positive effect of precipitation in May (and possibly in September) to activate landslides with regional extent. Extreme short-duration (1-day) precipitation events probably do not play a role in landslide triggering. Moreover, gradual increases in precipitation totals during periods of at least one-half year preceding the event years were detected.

Central European Variscan Basement in the Outer Carpathians: A Case Study from the Magura Nappe, Outer Western Carpathians, Poland

Exotic crystalline blocks within the Outer Carpathian flysch have the potential to establish the nature of their eroded basement source(s) and thus to reconstruct the paleogeography of the Outer Carpathians. Petrological investigations (including mineral analyses) coupled with zircon and apatite U-Pb dating were performed on an exotic crystalline block within Eocene siliciclastic rocks in the Rača Zone of the Magura Nappe in the Outer Western Carpathians, Poland. This exotic block is a large (c. 1 m diameter) pink porphyritic granitoid block found in the Osielczyk Stream, southeast of Osielec village in the Makowski Beskid mountains. The timing of magmatic crystallization is constrained by a U-Pb zircon age of 315.9 ± 2.6 Ma (MSWD = 0.69), while inherited zircon cores yield Archean (c. 2780 Ma), Cadomian (541.8 ± 6.7 Ma; MSWD = 0.53), Devonian (417 ± 11 Ma; MSWD = 0.57) and Early Variscan (c. 374 Ma) ages. Apatites from the same sample yield a Tera Wasserburg lower intercept U-Pb age of 311.3 ± 7.5 (MSWD = 0.87). The granitoid exhibits geochemical characteristics typical of I-type granites and εNd(316 Ma) = 2.15 (with a TDM model age of 1.18 Ga) and 87Sr/86Sr(316 Ma) = 0.704710. These data suggest a likely source region in the Saxo-Danubian Granite Belt, which possibly formed the basement of the Fore-Magura Ridge.