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In the Alpine Corsica (France), the Santa Lucia Nappe represents a peculiar unit preserving the unique relicts of Paleozoic lower to medium continental crust. It consists of composite basement affected by Permian granulite facies metamorphic conditions unconformably covered by a Late Cretaceous clastic sequence (Tomboni Conglomerate and Tralonca Flysch) affected by polyphase deformation and low‐grade‐metamorphism. In this work, we present a new reconstruction of the deformation events registered by the Tralonca Flysch during the Alpine orogeny. The D1 phase was testified by rare isoclinal folds. The D2 phase produced a continuous foliation and a map‐scale sheath‐fold with a top‐to‐W sense of shear. The D3 phase produced E‐verging non‐cylindrical folds and S3 crenulation cleavage that is not associated to metamorphic blastesis. We present the first temperature‐pressure‐deformation (P‐T‐d) path for the Tralonca Flysch, demonstrating that the Santa Lucia Nappe underwent accretion and then first stage exhumation in the Alpine wedge during the D1 phase with pressure and temperature peaks both occurred under blueschist metamorphic conditions. The D2 phase occurred at lower pressure‐temperature conditions during a second stage exhumation. This pressure‐temperature‐deformation path is comparable with those of the Lower Units (i.e., the subducted continental units of Alpine Corsica) suggesting a common geodynamic history. [ABSTRACT FROM AUTHOR]

The first results of U–Th–Pb isotope dating of detrital zircons (dZr) from the Chenka sandstones of the Cimmerides of Mountainous Crimea are presented. Carboniferous–Triassic dZr dominate among dZr from Chenka sandstones. Analysis of previously obtained sets of dZr ages from the age and lithologically different formations of Cimmerides of Mountainous Crimea has revealed certain regularities in the change in the time of the provenance signal and, accordingly, of the provenance areas, whose erosion products compose the studied formations. A comparison of the obtained of U–Pb ages of dZr from Chenka sandstones with similar dates obtained for sandstones from the Upper Triassic–Jurassic formations has shown that the provenance signals of the Chenka sandstones and Upper Triassic–Lower Jurassic flysch strata are different, but the provenance signals of the Chenka sandstones and Middle–Upper Jurassic coarse clastic strata are similar. Detrital zircons from the Chenka sandstones show that the parameters of the Th–U distribution in them are intermediate between those from sandstones of flysch and coarse-grained strata, respectively. In general, the isotope-geochronological and geochemical data we obtained and some features of the internal structure of dZr grains from the Chenka sandstones can be used as a strong argument in favor of considering Chenka sandstones as an independent stratigraphic unit with an age not older than the Middle Jurassic. The similarity of the characteristics of dZr grains from sandstones of the Chenka sandstones with those from Middle–Upper Jurassic sandstones casts doubt on the correlations of the Chenka sandstones with a number of lithologically similar units of the southwestern regions of Mountainous Crimea, specified as Early Jurassic in age based on finds of fossil remains. [ABSTRACT FROM AUTHOR]

The atypical Tien Shan and Carpathians flysch is compared and correlated to recognize the local (regional) and general (inter-regional) peculiarities of its structure and place in the evolution of mobile belts. The objects of study include the Upper Carboniferous flysch of the Khanaka Syncline (Tien Shan) and Upper Eocene flysch of the Podhale Syncline (Carpathians). Flysch of the Khanaka and Podhale synclines is compared for the first time using the historical–geological analysis based on the study of lithostratigraphy, tectonic structure, and geodynamic setting of objects. The objects of study belong to different mobile belts and tectonic cycles, but they are similar in internal structure and tectonic setting atypical of flysch and exhibit some features atypical of flysch: the formation on a quasiplatform basement, a significant volume of conglomerates, a simple configuration of geological bodies, an absence of internal deformations, and a narrow temporal period of formation. It follows from the comparative analysis that the studied objects belong to a specific flysch type that we suggest naming the final flysch of rear blocks of the mobile belts, whose formation reflects the specific geodynamic evolution of the Hercynian and Alpine mobile belts. [ABSTRACT FROM AUTHOR]

In the SE Alps, two Cretaceous–Eocene flysch basins, Julian and Brkini, filled with turbidite sediments, are present. This study novelly reports heavy mineral assemblage counts and detrital tourmaline characterization for 11 samples. It is possible to define three different groups, characterized by the presence of (1) a clinopyroxene–epidote–low-ZTR (zircon+tourmaline+rutile; 5%) sample association, (2) a high-ZTR (>48%)–garnet–apatite association and (3) a low-ZTR (<40%)–Cr-spinel–garnet association. Detrital tourmalines from both the Julian and Brkini flysch basins are rather similar in composition, associated with metapelites and metapsammites coexisting or not coexisting with an Al-saturating phase, ferric-iron-rich quartz–tourmaline rocks and calc–silicate rocks; however, their number is drastically different. In fact, even if the percentage of heavy minerals is very low and similar in both basins (0.17–1.34% in weight), in the Julian basin, the number of tourmaline crystals is much lower than that in Brkini (1–14 vs. 30–100), suggesting an important change in the provenance area. Interestingly, the presence of a high amount of tourmaline derived from ferric-iron-rich quartz–tourmaline rocks and calc–silicate rocks makes these two basins different from all the Cretaceous flysch basins of Bosnia and the Northern Dinaric zone, where these supplies are missing or very limited. [ABSTRACT FROM AUTHOR]

A technique to evaluate the degree of roundness of detrital zircons on a 5-point scale based on the preservation of crystal vertices, edges, and faces is presented. Based on measurements in individual grains, the integral roundness index Rs is calculated for a zircon grain set from various stratigraphic units. The obtained data make it possible to determine the proportion of different class grains in various sequences and to assess their similarity/difference degree, which can serve as an additional criterion for the differentiation of sedimentary sections. The proposed method is used to compare the roundness characteristics of detrital zircons from some Cimmeride sedimentary sequences in the Crimean Mountains. It is shown that relative to counterparts in the flysch sequences, sandstones of the Chenka sequence are characterized by a higher proportion of unrounded and weakly rounded zircons and a virtual absence of completely rounded grains. Value of Rs for the zircon grain set ranges from 3.41 and 3.95 for the Tauric Group to 2.55 for the Chenka sequence. Thus, Rs values in the sequences are marked by a significant difference, which is also confirmed by values of the mutual pair coefficient p calculated using the Kolmogorov–Smirnov test. [ABSTRACT FROM AUTHOR]

Heterogeneous rock masses that include rhythmic alternations of marl, shale, marly limestone, sandstone, siltstone, and argillite, such as Flysch, are particularly prone to generating colluvial deposits on gentle slopes, which are often subject to failures triggered by heavy rainfall. Flysch-derived colluvial soils are made up of highly heterogeneous sediments ranging from clayey loam to rock fragments, and they have been studied more rarely than homogeneous soils. In this work, we present a geotechnical and hydraulic characterisation performed both in situ and in the laboratory on flysch-derived colluvial soils that were involved in a channelised landslide in the pre-alpine area of the Friuli Venezia Giulia region (NE Italy). The investigated soils were characterised by the average values of the grain size composition of about 25% gravel, 20% sand, 30% silt, and 25% clay. The loamy matrix presented low-to-medium values of the liquid and plastic limits, as well as of the plasticity index (LL = 40%, PL = 23%, and PI = 17%, respectively). The values of the peak friction angle for natural intact samples were 33° < ϕ'p < 38°, whereas the residual friction angle fell to 23–24° at great depths and high vertical stresses, for a prevailing silty–clayey matrix. Variable head permeability tests were performed both in situ and in the laboratory, showing that the values of the vertical and horizontal permeability were very close and in the range 1 × 10−4–1 × 10−6 m/s. The soil permeability measured in the field was generally higher than the hydraulic conductivity calculated on laboratory samples. The proposed geotechnical and hydrological characterisation of flysch-derived colluvial soils can be of fundamental importance before the use of more thorough analyses/models aimed at forecasting the possible occurrence of slope failures and evaluating the related landslide hazard. The reported geotechnical and hydraulic parameters of flysch-derived colluvial materials can represent a useful reference for rainfall infiltration modelling and slope stability analyses of colluvial covers that are subject to intense and/or prolonged precipitation. However, when facing engineering problems involving colluvial soils, particularly those coming from flysch rock masses, the intrinsic variability in their grain size composition, consistency, and plasticity characteristics is a key feature and attention should be paid to the proper assumption of the corresponding geotechnical and hydraulic parameters. [ABSTRACT FROM AUTHOR]

We report a newly discovered hydrocarbon seep deposit from the Eocene bathyal flysch, exposed in the town of Buje in Istria, Croatia. Molecular fossils of methane‐oxidizing prokaryotes and abundant banded botryoidal cements indicate strong fluid flux at this site. We systematically describe the fauna of this and another seep deposit previously reported from Buje. The faunal assemblages are composed of eight species, these being an unidentified solemyid protobranch bivalve, the nuculid Nucula bowerbanki?, the nuculanid Nuculana? sp., the mytilid Brachidontes? amanoi sp. nov., the two thyasirids Channelaxinus dinaricus sp. nov. and Thyasira histriaensis sp. nov., the lucinid bivalve Amanocina bujensis sp. nov., and a possible provannid gastropod. The two assemblages are of low diversity (4 and 5 species, respectively), and are dominated by chemosymbiotic species whose occurrence is largely restricted to seeps. Despite their spatial and stratigraphic proximity, the two deposits share only a single species, Channelaxinus dinaricus, probably due to different fluid flux regimes at both seeps. The Buje seep assemblages are among the very few Late Cretaceous to Palaeogene chemosynthesis‐based faunal assemblages from the Tethys Ocean (the others being Late Cretaceous vent assemblages from Cyprus). From an evolutionary perspective, the Buje seep communities consist of genera with Mesozoic origins but lack Cenozoic novelties such as bathymodiolin mussels and vesicomyid clams, which are known from coeval deposits from the Pacific and dominate vents and seeps today. Thus, the Buje seep fauna support previous assertions that the Eocene Tethyan seep faunas preserved an ancient aspect, whereas evolutionary novelties arose in the Pacific. [ABSTRACT FROM AUTHOR]

Nutrient imbalances may negatively affect the health status of forests exposed to multiple stress factors, including drought and bark beetle calamities. We studied the origin of base cations in runoff from a small Carpathian catchment underlain by base-poor flysch turbidites using magnesium (Mg), calcium (Ca) and strontium (Sr) isotope composition of 10 ecosystem compartments. Our objective was to constrain conclusions drawn from long-term hydrochemical monitoring of inputs and outputs. Annual export of Mg, Ca and Sr exceeds 5-to-15 times their atmospheric input. Mass budgets per se thus indicate sizeable net leaching of Mg, Ca and Sr from bedrock sandstones and claystones. Surprisingly, δ26Mg, δ44Ca and 87Sr/86Sr isotope ratios of runoff were practically identical to those of atmospheric deposition and soil water but significantly different from bedrock isotope ratios. We did not find any carbonates in the studied area as a hypothetical, easily dissolvable source of base cations whose isotope composition might corroborate the predominance of geogenic base cations in the runoff. Marine carbonates typically have lower δ26 Mg and 87Sr/86Sr ratios, and silicate sediments often have higher δ26Mg and 87Sr/86Sr ratios than runoff at the study site. Mixing of these two sources, if confirmed, could reconcile the flux and isotope data. [ABSTRACT FROM AUTHOR]

The nearly continuous volcanic eruption record at Mt. Etna dating back ~700 years provides an excellent opportunity to investigate the geochemical evolution of a highly active volcano. Of particular interest is elucidating the cause of selective enrichment in alkali elements (K and Rb) and 87Sr/86Sr observed in various episodes of past activity. More recently, this alkali enrichment trend started to manifest in the 17th century and accelerated after 1971, and was accompanied by an increase in the volume, frequency, and explosivity of eruptions. Explanations for this signature include recharge of alkali-enriched magmas and/or crustal contamination from the subvolcanic basement. This study quantitatively examines the role of crustal contamination in post-1971 Etnean magma compositions via hundreds of open-system phase equilibria and trace element calculations based upon whole-rock major oxides, trace elements, 87Sr/86Sr ratios, and mineral compositional data. Available pre-1971 petrochemical data are satisfactorily reproduced by fractional crystallization of a high whole-rock MgO (12–17 wt.%), Ni (135–285 ppm), and Cr (920–1330 ppm) parental magma composition that is documented in Etna's ~4-ka fall-stratified deposit. Observed post-1971 whole-rock and glass trends and phase equilibria are reproduced via modeled assimilation of a skarn and flysch mixture, lithologies that represent the uppermost 10 to 15 km of sedimentary rocks beneath Etna. Notably, models show that K2O (wt.%) and Rb (ppm) behave incompatibly during partial melting of skarn/flysch. Additionally, the observed elevation of 87Sr/86Sr in post-1971 samples is consistent with the addition of radiogenic Sr from wallrock partial melts. In best-fit models, which yield observed post-1971 K2O, Rb, and 87Sr/86Sr trends, ~17% anatectic melt is assimilated and there may be a subordinate stoped wallrock component of ≤2% (percentage is relative to the starting mass of pristine magma). Previous work has shown that metasomatized spinel lherzolite and garnet pyroxenite can be melted in different proportions to reproduce long- and short-term changes observed in Etna's geochemical products. We propose that the alkali enrichment signature observed after 1971 can be fully explained through the combination of mantle heterogeneity and crustal contamination. In particular, up to ~20% crustal input coupled with mantle heterogeneity of primitive melts explains the geochemical signals quite well. The influence of crustal contamination on post-1971 lavas is, in part, the result of frequent recharge of magmas that thermally primed the middle to upper crust and enhanced its partial melting. [ABSTRACT FROM AUTHOR]

Steep slopes in soft rock are characterized by their susceptibility to instability (rockfall, rockslide) due to weathering and erosion of the slope surface. This article deals with the problem of adapting to the increasing height of the scree slope. The construction of a retaining wall in a scree slope in front of a slope of soft rock with a steep face, where a very rapid weathering and erosion process of weathered material takes place, and the simultaneous deposition of material in front of the steep slope is a common solution. Changes in the geometry of the slope and the front scree are taken into account, and at the same time, sufficient safety against rockfall must be ensured. The analysis is shown on a specific example of a steep flysch slope near Split, Dalmatia. The retaining wall solutions are compared in terms of function, cost and sustainability. The construction of a single colossal, reinforced concrete retaining wall shows that this solution is not feasible due to the high construction costs and CO2 emissions of the retaining wall. A model was therefore developed to determine the height of the retaining walls for different construction time intervals and distances from the original rock face. The critical failure modes were investigated for various retaining wall solutions with regard to the highest degree of utilization of the resistance, which also allows the cost-optimized solutions to be determined. By building two or more successive retaining walls at suitable intervals and at an appropriate distance from the original rock face, construction costs and CO2 emissions can be significantly reduced. [ABSTRACT FROM AUTHOR]

During the re-mapping of the area for the Geological Atlas of Switzerland, a significant stratigraphic unconformity was discovered in the North Penninic (Valais) Bündnerschiefer and the Flysch series of the northern Prättigau. It separates different units of the Cretaceous Bündnerschiefer from the Palaeogene Flysch. We explain this observation by a basin conversion from extension to compression, which caused the initial deformation of the Bündnerschiefer in an accretionary wedge. Interlinked return-flow has created a new heterogeneous substrate for the flysch sediments and explains the different types of unconformities. The basin conversion coincided with high-grade metamorphism in the vicinity of the the South Penninic suture and the Austroalpine units, and the increased exhumation in the Austroalpine nappe stack. Detrital zircon dating confirms also a change from European to Austroalpine detrital sources in the flysch sandstones. We discuss a palaeotectonic model leading to hP/lT metamorphism of the Bündnerschiefer in the Late Eocene (c. 42 Ma). It appears that the flysch formations were also involved, but to a lesser degree by tectonic deformation from the late Early Eocene onwards, as the pervasive folding characteristic of the Bündnerschiefer is absent. This has been followed by a phase of S-directed backfolding. During the Oligocene and Miocene, more extensive deformation occurred by SE to NW compression and finally by probable westward thrusting and folding. Our main theme is the transition from passive to active continental margins, which in Alpine plate tectonic framework corresponds to the transition to flysch sedimentation by basin conversion. Our results show that the simultaneity of the transition from extension to compression, as indicated by the accumulation of flysch, shifted in time from south to north in the Alpine Tethys. [ABSTRACT FROM AUTHOR]

Uncertainties related to runout distances in shallow landslide analyses may not only affect lives but may also result in economic losses. Owing to the increase in shallow landslides, which are especially triggered by heavy rainfall, runout distances have been investigated to decipher whether applications of a functional runout distance are feasible. This paper aims to give insights into the modeling of the shallow landslide runout probability in Eocene flysch facies in the Western Black Sea region of Türkiye. There are two main stages in this study—which are dominated by empirical models, the detection of initiation points, and propagation—which help us to understand and visualize the possible runout distances in the study area. Shallow landslide initiation point determination using machine learning has a critical role in the ordered tasks in this study. Modified Holmgren and simplified friction-limited model (SFLM) parameters were applied to provide a good approximation of runout distances during the propagation stage using Flow-R software. The empirical model parameters suggested for debris flows and shallow landslides were investigated comparatively. The runout distance models had approximately the same performance depending on the debris flow and shallow landslide parameters. While the impacted total runout areas for the debris flow parameters were predicted to amount to approximately 146 km2, the impacted total runout areas for the shallow landslide parameters were estimated to be about 101 km2. Considering the inclusion of the RCP 4.5 and RCP 8.5 precipitation scenarios in the analyses, this also shows that the shallow landslide and debris flow runout distance impact areas will decrease. The investigation of runout distance analyses and the inclusion of the RCP scenarios in the runout analyses are highly intriguing for landslide researchers. [ABSTRACT FROM AUTHOR]

We have studied Rayleigh wave group velocities beneath the Aegean region of Türkiye using ambient noise tomography. Noise data were gathered from 43 broadband seismic stations belonging to three permanent broad-band arrays. The cross-correlation method was used to estimate empirical Green's functions. Group velocities of the fundamental mode Rayleigh waves were determined using multiple filter technique. We measured dispersion for each station pair in a period range of 2-12 s and computed maps of group velocity distribution using the fast marching surface tomography method. The group velocity maps correlate well with the geological and tectonic features of the region, displaying low velocities for the Quaternary alluvial basins, moderate velocities for Cretaceous rocks, and high velocities for the regions where gneiss and granitoid rocks outcrop. Low velocity anomalies may be associated with the grabens and horsts formed by faulting and to deep mantle flow. We detect potential offshore geothermal zones in Izmir and Candarli Bay. The information from broad-band networks improves the resolution of crustal surface wave velocity structures, particularly for shallow depths. This improvement will support the assessment of seismic hazard, as the shallow layers of the crust contribute significantly to seismic activity. [ABSTRACT FROM AUTHOR]

Based on the field observations and tectono-sedimentary analysis, we suggest reconstruction of the geological evolution from case study of Northern Tunisia since the Eocene age. The reconstruction of the structural architecture of this region can be aided by knowing the spatiotemporal occurrence and the deformation of the Oligo‒Early Miocene deposits. In the research area, two depositional basin types that coexisted but in different tectonic settings were seen in the reconstruction of Oligo‒Early Miocene successions. In Northern Tunisia, the Late Eocene shortening episode led to a thin-skinned deformation that produced irregular basement topography. During the Oligo‒Early Miocene subduction process, the earliest lithofacies of the Maghrebian Numidian flysch deposited in deep marine offshore environment. Synchronously in the onshore, the second lithofacies of Fortuna were deposited in NW-trending extensional structures after a rifting episode that characterized north-eastern Tunisia (ante-nappes). During the Middle Miocene, the curving fore-arc of subduction between Africa and the Mesomediterranean Microplate dominated northern Tunisia. As a result, the Numidian basin was raised, resulting in thrust sheets in northwestern part of Tunisia, while the extensional structures supporting the Fortuna succession were closed and created push-up structures following transpressional deformation along the NW‒SE boundary faults. Continental collision has occurred in northern Tunisia since the Late Miocene, resulting in shortening structures, some elevated areas, and sedimentary gaps encompassing a substantial portion of the study area. [ABSTRACT FROM AUTHOR]

This study aims at identifying the source area(s) of two populations of exotic pebbles/cobbles present as driftwood dropstones in the upper Turonian to Coniacian pelagic layers of the Scaglia Rossa, as well as gravity flow deposits in the Santonian Sirone Conglomerate of the Lombardian Flysch. The clast assemblage indicates that the main source(s) were the structurally highest Austroalpine units of the Eo-Alpine orogenic edifice of the Eastern Alps and the Transdanubian Range; the erosion of such units produced Gosau-type gravels that, after local elaboration in highenergy settings, were resedimented into the Southalpine basins. Despite the affinities shown by the clast composition with the lithofacies of the Lombardian stratigraphic succession, origin from a central-Southalpine early orogenic retrobelt edifice can be reasonably excluded, since the onset of uplift and denudation of the Southern Alps occurred in the Late Oligocene. In Santonian times, a complementary source fed the Sirone Conglomerate and likely contributed the Kainach Gosau basin with clasts of Southalpine rocks. This source is inferred to have coincided with an emerging belt located in the eastern Southalpine domain, produced by transpression along the proto-Periadriatic Lineament. Ophiolitic detritus may have reached the Central Alpine and Southalpine areas during the Early Cretaceous; in contrast, the exhumation and uplift of the Koralpe-Wölz high-pressure belt and of its uppermost Austroalpine nappe cover at 89-84 Ma, likely separated the Southalpine retrobelt basins from 'northern' sources. [ABSTRACT FROM AUTHOR]

The deeply buried, northeastern segment of the fold-and-thrust belt of the Outer Carpathians is contoured by synorogenic sediments (Upper Oligocene-Lower Miocene) of tectonically multiplied thicknesses, which mask the deep-seated structures. Integration of archival mappings and profiles of deep wells with the new generation of geological-seismic cross-sections reveals the unconformable position of asymmetric folds and duplexes built of synorogenic sediments, resting upon the older flysch formations (Cretaceous-Lower Paleogene). These structures are cut by a system of dislocated, monovergent, imbricated overthrusts, deeply rooted in the outer zones of thrust folds. These zones are associated with deep-seated, high-amplitude (up to several kilometres), Meso-Paleozoic and Precambrian faults originated by subduction of the European Platform. As revealed by geological reinterpretation of MT-1 magnetotelluric soundings, the time/space identification of longitudinal, compressional sutures rotated by transversal, transpressional faults suggests a segmented model of subduction of the platform basement. Its coincidence with the reconstructed kinematic evolution of sedimentary covers justifies the origin of the inversion tectonics of the Central Depression of the Outer Carpathians as a result of the heterogenic structure of the consolidated basement. [ABSTRACT FROM AUTHOR]

The Pieniny Klippen Belt (PKB) is located between the Central and the Outer (Flysch) Carpathians and forms a narrow zone with a complex structure, often described as a mélange. It is composed of numerous tectonic elements of different size including strike-slip-bounded tectonic blocks, thrust units, toe thrusts and olistostromes combined together and representing different lithologies. To aid the geological interpretation of the mélanges of the PKB in the Spiskie Pieniny Mountain Region (South Poland), seismic refraction tomography was conducted. Isolated limestone outcrops consist of Jurassic limestones that stand out in the landscape. They form the horizontal narrow belt. In this belt, limestone olistoliths are surrounded by a matrix consisting of sandstones, mudstones and marl sequences forming a sedimentary mélange. The seismic refraction tomography measurements conducted along three profiles across this belt showed significant horizontal and vertical seismic velocity variations, which revealed the complex geological structure of this area. The Złatne, Branisko and Hulina Units were distinguished within the PKB structure. The high-velocity objects detected within the Hulina Unit were found to correspond to limestone outcrops and form isolated blocks surrounded by flysch deposits representing a chaotic sedimentary complex. [ABSTRACT FROM AUTHOR]

The first results of the U–Th–Pb isotope dating of detrital zircons (dZr, N = 130, n = 91) from the middle Danian sandstones (63.9–65.3 Ma) of the Cretaceous–Eocene Novorossiisk–Anapa flysch widely developed in the Sochi synclinorium (southern slope of the Western Caucasus) are presented. The maximum and minimum dZr age is 2973 ± 12 Ma and 318 ± 3 Ma, respectively; weighted average age of the four youngest dZr is ~322 ± 7 Ma. There are no signs of erosion products of the Jurassic magmatites involved in the structure of the Greater Caucasus and Crimean Mountains into the sedimentary basin, where the Novorossiisk–Anapa flysch was formed. The results have revealed a high degree of similarity between the provenance signals of the Danian sandstones from the Novorossiisk–Anapa flysch, some Paleogene–Neogene and Early Quaternary (Early Pleistocene) sandstones of the Western Caucasus and Western Cis-Caucasia, red-colored Upper Permian and Lower Triassic sandstones of the Moscow syneclise, as well as Late Quaternary alluvium at lower reaches of the Don and Volga rivers draining vast expanses of the Russian Plate. These facts suggest: (1) the absence of eroded mountain structures of the Greater Caucasus and Crimea in the middle Danian; (2) the main volume of detrital material composing the Novorossiisk–Anapa flysch was formed due to the recycling of Permian–Triassic and younger sequences of the Russian Plate. [ABSTRACT FROM AUTHOR]

This study is based on the detailed sedimentological analysis of eleven sections and one well through the late Eocene–Oligocene flysch formation of the Internal Ionian Zone (IIZ) in Western Greece. The sections are spread from the northern parts of Epirus to the north and Aitolokarnania to the south. Sedimentological data combined with biostratigraphic analyses resulted in a five-stage evolutionary model for the basin. Unit I corresponds to the lower part of the examined sections, indicating the onset of clastic sedimentation. Regarding depositional environments, it is regarded as a basin plain where lobe distal fringe accumulations occur. Unit II consists almost exclusively of heterolithic facies, marking the advance of a lobe complex system. Massive sandstone facies dominate unit III and can be considered a more proximal submarine fan system. Unit IV reflects a calm period of the basin, where mud-dominated heterolithics and hemipelagic mudstones were deposited. Hemipelagic mudstone facies with intervals of heterolithics, conglomerates, and deformed and massive sandstone facies characterize unit V. The architecture resembles a slope system incised by canyons and channels. The sand-rich intervals in Units III and V could act as the most favorable reservoir levels. In contrast, the sand-rich intervals in Unit II are considered less promising due to their higher heterogeneity. [ABSTRACT FROM AUTHOR]

Progressive industrialisation and urbanisation in recent decades have dramatically affected the soil cover and led to significant changes in its properties, which inevitably affect the functioning of other components of the forest ecosystems. The total content of Pb, Cd, Zn, Fe, Cr, Cu, Ni, As, and Hg was studied in twenty-five plots at different heights in the topsoil (organic and humus horizons) formed from the Carpathian flysch in the area of the Silesian Beskids (Western Carpathians). The aim of this article is to analyse the spatial distribution of potentially toxic elements in the mountain forest topsoil in different types of plant communities and to determine the relationship between altitude and potentially toxic elements contamination. The soils studied are acidic or very acidic, with an average range of 3.8 (H2O) and 2.9 (KCl). Concentrations of the metals Cd, Zn, Fe, Cr, Cu, Ni, and Hg on the plots that were analysed are within the range of permissible standards for forest ecosystems in Poland, while Pb and As exceed the permissible standards for this type of ecosystem. Spearman's rank correlation coefficient showed a high correlation between Fe–Cr (r(32) = 0.879, Pb-Hg r(32) = 0.772, Ni–Cr r(32) = 0.738, Zn-Cd r(32) = 0.734, and Cu-Hg r(32) = 0.743, and a moderate statistically significant positive correlation between Cu-Pb r(32) = 0.667 and As-Pb r(32) = 0.557. No correlation was found between altitude and the occurrence of potentially toxic elements. The geo-accumulation index (Igeo) index, on the other hand, indicates that Pb, As, and Cd have the highest impact on soil contamination in all study plots: it classifies soils from moderately to strongly polluted. The enrichment factor (EF) obtained for As and Hg indicates significant-to-very high enrichment in all areas studied. The potential ecological risk index (PLI) calculated for the sites indicates the existence of pollution in all areas examined. The highest risk categories (considerable to very high) are associated with cadmium and mercury. [ABSTRACT FROM AUTHOR]

An in situ electron microprobe study of detrital minerals yielded important insights into the diagenetic history of the Cretaceous-to-Paleogene flysch sandstones from the Chvalčov site, Rača Unit, Flysch Belt of the Outer Western Carpathians. Detrital titanite and a Fe-Ti mineral (probably ilmenite) were almost completely altered to TiO2 minerals, which also newly crystallized in intergranular spaces of sandstone. Brookite, anatase, and, exceptionally, rutile were identified by Raman spectroscopy. Authigenic TiO2 phases show complex composition with occasionally elevated contents of Fe, Nb, Zr, V, Sc, Cr, Al, Y, and/or P, which were likely sourced from altered neighboring heavy minerals. In addition, rare authigenic LREE- and Y-enriched apatite rims were observed on detrital apatite. The remobilization of REE, Y, and HFSE was likely mediated by acidic early diagenetic fluids enriched in fluoride and sulfate anions. The superimposed formation of calcite cement was associated with the dissolution of detrital garnet, feldspars, and quartz. The compositions of detrital apatite and garnet (Alm60-82Prp4-30Sps0-24Grs0-19) are comparable with those from adjacent parts of the Flysch Belt. Detrital rutile is enriched in Nb, V, Cr, and Zr. Our study illustrates the intensity of diagenetic alteration of detrital minerals in flysch sandstones as well as the usefulness of in-situ electron-microprobe investigations for the recognition of processes influencing heavy minerals in diagenetically altered sediments. [ABSTRACT FROM AUTHOR]

In an anthropocynical epoch of severe environmental crisis, geoscientists have unique skills to drive the transition to sustainability. Therefore, the geological literacy of society is essential to seek solutions to major challenges. However, the formal education of geology differs considerably from the desirable. Fortunately, there are out of school organizations in charge of geology outreach. In this work, an analysis and redesign of the teaching material offered by the GeoEskolak program of the Geopark of the Basque Coast is carried out. This material is aimed to 4th grade secondary education students who visit the Flysch of Zumaia. The new "Teacher's Manual" has been developed following the strategy defined by the DBS methodology for the design of a sequence and is adapted to the LOMLOE curriculum and the Sustainable Development Goals. [ABSTRACT FROM AUTHOR]

The Malaguide Complex occupies the highest position in a thick-skinned Alpine thrust stack. It includes polydeformed, sedimentary and low-grade metamorphic rocks of Palaeozoic basements and their Meso-Cenozoic covers. NE of Granada the complex results severely sheared and stretched along the Betic suture zone in the metamorphic hinterland (orogenic backstop). The suture developed after the Burdigalian, due to oblique collision of the Alboran Domain (including the Malaguide Complex) with the South-Eastern Iberian Paleomargin. The orogenic evolution in the backstop region started with late Palaeogene to Early Miocene N-directed pre-collisional shortening and early thrust stacking, associated with low-grade metamorphism in the lowest Malaguide units increasing downwards into the underlying Alpujarride Complex. An accretionary prism developed at the expense of deep-marine (Flysch) sediments and the sedimentary covers of the Iberian and Alboran conjugate margins (External Zones and Frontal units, respectively). Later orogenic stages were characterized by SSE-directed back-folding and -thrusting in the Middle Miocene affecting both sides of the Betic suture related to dextral wrenching causing plurikilometric displacements. In this way, the suture evolved towards a several kilometres wide megashear zone (Cogollos-Diezma Corridor), prior to a final phase of SW-directed post-orogenic extension in the Late Miocene. Despite this protracted Alpine evolution, the Malaguide basements also preserve a record of orogenic activity during Late Carboniferous stages of the Variscan Orogeny in the form of a set of NE-SW trending folds with SE vergence and associated slaty cleavage, which are not found in the post-Carboniferous cover. The temperature conditions of this event (>300°C) in the less metamorphic Malaguide units are determined by colour alteration index (CAI) data from conodonts that have also allowed biostratigraphic dating of the Devonian-Carboniferous successions. [ABSTRACT FROM AUTHOR]

Soil is one of the most important natural resources of any country, erosion process degrades the soil and leaves irreparable damage. The aim of this study is to estimate the rate of soil erosion and its relationship with landforms and lithology unites of Zonuzchay catchment in Marand county. In this study was used the modified global model of soil loss (RUSEL), geographic information system (GIS) and remote sensing (RS) to estimate the rate of soil erosion. To implement the model, rainfall erosivity factors (R), soil erodibility factor (K), slope length-gradient factor (LS), conservation practice factor (P) and cover management factor (C) in Arc GIS environment calculated and Then a soil erosion map was drawn in five class of hazard (very low, low, medium, high and very high). Topographic position index (TPI) was used to classify and map the landforms of the catchment. Then, the role of different landforms and lithology unites in relation to soil erosion rates was investigated by combining relevant maps. The results showed that the values of Average soil erosion is 1.71 tons per hectare per year. Valleys and deeply incised streams on heights and slopes (94.27 km2) and then Mountain tops and high ridges (89.21 km2) have the highest rate of erosion. In Zonuzchay catchment, soil erosion is mostly on the flysch type deposits, red and gray conglomerates with Marl layers and alluvial terraces. Investigation of regression relationships between (RUSLE) model factors and soil erosion of Zonuzchay catchment showed that the slope length-gradient factor (LS) has the greatest effect in calculating the rate of erosion of Zonuzchay catchment. [ABSTRACT FROM AUTHOR]

Windthrow is a phenomenon that causes major changes to tree stand evolution by blowing down or breaking either isolated trees or entire tree stands, with a strong ecological, social and economic impact. Both scattered and large-scale windthrow occurred in spruce (Picea abies (L.) Karst.) tree stands of Romania. They affected surfaces of various dimensions from harvestable forests. Such a phenomenon took place in the Curvature Carpathians in February 2020. Large-scale windthrow occurred in this area in 1995 as well, in the upper watershed of Bâsca river. Using the climate data from February 2020, this paper aims to identify the manner in which factors such as climate and site conditions together with tree stand characteristic and the anthropogenic factor impacted and influenced the occurrence of windthrow. The results showed that the intensity of this phenomenon had maximum effects when the wind coming from north/northeast reached the maximum speed of 32 m·s−1. Pure spruce tree stands situated on slopes with an inclination between 16 and 30° were mainly affected. Their position was counter to the wind direction, at an altitude between 1300 and 1500 m, on cambisols and spodosols. The analysis and statistical interpretation of data in the case of scattered and large-scale windthrow from the two management units showed that the same factors studied influence the variation of windthrow intensity in a different manner, or sometimes they do not influence it at all or they can only account for a small part of this variation. [ABSTRACT FROM AUTHOR]

The widely debated late Oligocene-middle Miocene Numidian Fm (NF) consists of supermature quartzose sediments deposited in the Maghrebian Flysch Basin (MFB) outcropping from the Betic Cordillera to the Southern Apennine passing by the Maghrebian Chain. The NF is commonly composed of three lithostratigraphic members and is characterized by two vertical successions (Type A and Type B) corresponding to different sedimentation areas in the MFB. It is noteworthy the occurrence of widespread lateral successions of the NF (Types C, D and E) indicating in some cases an interference of the Numidian sedimentation with other different depositional systems and supplies. The Type C 'Mixed Successions', deposited in depocentre areas, are composed of supermature Numidian supply interfingering with immature siliciclastic materials, coming from the internal portion of the MFB. The Type D consists of supermature Numidian materials supplied from the Africa Margin (external sub-domains) deposited in sub-basins on the Africa-Adria margins, outside the typical Numidian depositional area. The Type E, which stratigraphically overlies both the South Iberian Margin (SIM) and the Mesomediterranean Microplate (MM), represents the migration of the Numidian depositional system to reach the opposite margins of the MFB. The occurrence at a regional scale of all the above-mentioned lateral successions reveals a great evolutionary complexity resulting also from further constraints, which must be considered for palaeogeographic and palaeotectonic reconstructions. Another important point deals with the diachronism of the top of the NF, observed eastward from the Betic-Rifian Arc and the Algerian-Tunisian Tell (Burdigalian p.p.) to Sicily (Langhian p.p.) and up to the Southern Apennine (at least Langhian/Serravallian boundary) which can be related with eastwards delay in the MFB closure. The palaeogeographic reconstruction of the Numidian depositional area presented in this paper, which is also included into a global kinematic model, represents a first attempt to use the software GPlates for this subject. [ABSTRACT FROM AUTHOR]

A highway embankment founded on a sloping tectonised marly-sandstone flysch formation located in the Apennines chain (Italy) has been affected for about 30 years by continuous slow movements. Given the strategic importance of the involved infrastructure, different investigation and monitoring campaigns have been carried out to get information about the properties of the involved soils and collect data about the displacements and piezometric regime. Field monitoring, in particular, reveals that the observed displacements result from a failure mechanism involving both the embankment and the foundation soils. However, significant gaps in monitoring jeopardize the possibility to assess the long-term trends in the displacements and piezometric regime and the significance of weather forcing in regulating the phenomena. To address such research questions, a procedure, easily transferable in different contexts, is proposed and applied to the test case: a simple hydrological proxy indeed permits evaluating the rate of movement featured by weatherinduced seasonal variability. Such a mechanical response has been confirmed by the results of a simplified numerical model aimed at finding out the main features of the observed kinematics accounting for a hydrological balance of the involved area. [ABSTRACT FROM AUTHOR]

This study presents the characteristics of the current course of the phenomenon of droughts and floods in the catchment area of a man-made mountainous reservoir and forecasts of water inflow changes to the reservoir over the next three decades. The catchment area of the Klimkówka reservoir on the Ropa River, a tributary of the Wisłoka River, located within the Polish Carpathians was selected for the study. The analysis carried out, using Soil and Water Assessment Tool (SWAT) modelling among other techniques, showed an increase in the importance of low-flow outflow from the upper Ropa catchment and a negative balance of inflow to the reservoir (Q < 2 m3s−1), manifested by a prolonged duration of low flows and an increase in outflow deficit during the year. The duration of flood flows and the runoff excess during these periods show a constant or decreasing tendency, while the length and excess of runoff increase during large floods. Thus, in the upper Ropa catchment, an increase in the intensity of extreme hydrological phenomena is observed. The prepared forecasts indicate an increase in annual runoff from the catchment in the decades 2021–2030 and 2031–2040 and a marked decrease in the decade 2041–2050. In the annual cycle, the projected changes in the coming decades will take different directions. In December only, throughout the entire period 2021–2050, the outflow will increase, whereas in May it will systematically decrease. [ABSTRACT FROM AUTHOR]

The Moesian Platform represents a major tectonic unit of the foreland of the Carpathians and Balkans, spanning across the southern part of Romania and the northern part of Bulgaria. Although the Moesian Platform is considered to be a stable tectonic unit, it has played a significant role in the geological history of the region, influencing the development of the surrounding Carpathian and Balkan mountain ranges, making it an area of interest for studying tectonic history, geological structures, and landscape evolution. In the southern part of the Moesian Platform in Romania, delineated to the north and to the east by the steep slopes of the Argeş River valley and to the south by the steep slopes of the Danube River valley, an elevated and W–E promontory-looking geomorphological feature identified by the local inhabitants as "hill" is distinct from the neighbouring flat relief of the Romanian plain. This study is the result of a comprehensive investigation into the geomorphological features and neotectonic structures within this region. An intriguing outcrop displaying a filled fault, cutting and displacing the Quaternary sedimentary formations of the recently named Argeş Promontory, shed light on recent tectonic activities that have influenced the landscape. By integrating field observations, geological, and tectonic data, as well as satellite geodetic data, our results contribute to a better understanding of the study area's regional geodynamics, emphasizing the significant role of tectonic activity in shaping the present-day landscape. [ABSTRACT FROM AUTHOR]

The paper presents seven species of the genus Aspidoceras Zittel 1868 and three species of the genus Pseudowaagenia Spath 1931, found in the "Acanthicum Beds" Formation, from the Ghilcoș Kimmeridgian (Hăghimaș Mountains, Romania). In addition to the species previously described by other authors (Neumayr, Herbich and Preda), six more species have now been highlighted that complete this association: Aspidoceras sesquinodosum, A. uninodosum, A. hystricosum, A. rogoznicense, Pseudowaagenia micropla and P. acanthomphala. At the same time, the specimens described by previous authors were also reviewed. [ABSTRACT FROM AUTHOR]

Changes in local hydrological and climatic conditions over the last 5500 years have been reconstructed based on geochemical and paleobiological features recorded in the sediments of two mountain lakes. The lakes are located in the Tatra Mountains, in the highest mountain range of the Carpathians (Central Europe), which during the Holocene constituted an important climatic barrier. Because both studied lakes are relatively shallow, even relatively minor fluctuations in water level are clearly recorded both in the geochemical characteristics of the sediments and in the phyto- and zooplankton communities. The multiproxy records indicate several periods of high water stands: 5.4–5.2 ka, 3.5–2.7 ka, 1.4–1.0 ka and 0.5–0 ka, and prominent dry periods 2.7–2.1 ka and 1.7–1.5 ka. Comparison of the reconstructed water levels of the Tatra lakes with records from other European regions suggests that at the boundary of the Middle and the Late Holocene, the hydrological conditions in the Tatras were similar to those in Western and Central Europe. Later, beginning approximately 3500 years ago, records from the Tatras, the northern surroundings of the Pannonian Basin, and the southern part of the Carpathians were unified. In addition to changes in local and regional hydrology, the records from the studied lakes allowed us to reconstruct changes in lake productivity. Relatively high δ13C values, compared to the sedimentary organic matter of other lakes in the region, point to in-lake primary production as a major source of sedimentary organic matter in both lakes. The stable C:N ratio values suggest a constant proportion of organic matter coming from in-lake primary production and transported from the lake catchment. However, the amount of organic carbon and nitrogen and, most of all, differences in the composition of stable C and N isotopes indicate changes in the lake environment. These changes were correlated with some paleotemperature proxies from the region. [ABSTRACT FROM AUTHOR]

The active drainage network (ADN), as a dynamic component of a catchment, plays an important role in a catchment's functioning. Changes in the ADN are the most noticeable during extreme hydro-meteorological events, and they result from, among others, the incorporation of man-origin incisions into the ADN. Knowledge of the parameters of the "real" ADN is a key element in the field of catchment hydrology because the ADN affects the intensity of hydro-, geomorpho-, and biological processes. The goals of this study are to assess (1) the changes in the ADN during extreme hydro-meteorological events (with special attention paid to the human-induced impact on the ADN transformation) and (2) the consequences of the ADN changes on the hydrological response of a catchment and their impact on the flood hazard/risk management processes. The study was performed in a mountain catchment, prone to flash flood occurrences. The ADN was reconstructed with the use of ALS-LiDAR data using GIS tools, and the hydrological response was evaluated by using SCS-CN and GIUH models. The results revealed that the ADN functioning during heavy rainfalls is three to four times denser than the natural-origin river drainage network (RDN) (11.4 km·km−2 vs. 2.9 km·km−2), and the RDN is significantly modified by human-origin elements (e.g., roads, ditches, furrows, etc.—they constitute ca. 1/3 of the ADN). Moreover, significant structural changes in the ADN have occurred, which were confirmed by the Hortonians' type of analysis. The changes in the ADN have affected the hydrological response of the catchment (predominantly an increase in the peak flow—up to 7%) and the dimensions of the 1% probable flood hazard zone (increase of ca. 5%). It may be concluded that significant changes in the ADN, in the catchment studied, had a moderate impact on the changes in the flood hazard level. The results give a new insight into the flood hazard/risk assessment processes in a small flysch mountain catchment. [ABSTRACT FROM AUTHOR]

Slope movement processes include complex soil and rock failure mechanisms. Their study benefits from a multidisciplinary approach based on a wide range of information including geological and geomorphological mapping, and geotechnical and geophysical investigations. This research paper focuses on the characterization of the Tamentout landslide that occurs in the southeast of Jijel province. The study area belongs to the Tellian domain in which the geological outcrops are dominated by Senonian formations, composed of marl deposits overlain by Numidian flysch of Aquitano-Burdigalian age, with a sloping topography ranging from 20° to 30°. The geophysical approach consists of processing the available geophysical data of resistivity, obtained by the Electrical Resistivity Tomography (ERT). This study aims to characterize the internal structure, and the changes in water saturation within the unstable mass and locate the depth of slip surface associated with this landslide. Through this work, we combined geological and geotechnical investigations with electrical resistivity tomography (ERT). This combination gave a more detailed image of the substrate geology and structure of the landslide zone. The 2D resistivity results show that the basement consists of two main formations. The first one is a highly conductive formation with a resistivity range between 2 and 25 Ωm, a depth of 0-8 m, and is interpreted as a saturated marl-clay overlaying. The second, a hard and compact formation with a resistivity range between 50 and 200 Ωm and a depth range of 8 to 40 m, was interpreted as a substrate of tellian marls. The presence of boulders of Numidian sandstone within the two formations is materialized by a very high resistivity value ranging from 500 to 1000 Ωm. The slip surface was located on the layer with low resistivity (2-25 Ωm). The precise determination of the depth of the shear zone is of vital use in implementing mitigation measures and carrying out the stabilization work of this unstable zone. Through this work, we will highlight the advantage of the combination of available results of the geological, geotechnical investigations and electrical resistivity tomography (ERT) carried out in the study area. [ABSTRACT FROM AUTHOR]

This contribution analyses the structural architecture and tectono-metamorphic evolution of Briançonnais units in the southern French-Italian Western Alps. The studied area extends from a virtually non-metamorphic area adjacent to the Helvetic-Dauphinois External Domain in the west to the Monviso-Queyras ocean-derived units in the east, where metamorphism increases up to eclogite-facies. Mapping at the scale 1:10.000 of a mountainous part of the Ubaye-Maira transect was performed, which portrays in detail the Briançonnais units over ~ 100 km2. The lithologies include meta-andesite, meta-siliciclastics, marbles, turbiditic calcschists and flysch whose age spans from Late Carboniferous to Eocene. Metamorphism is low-grade greenschist-facies in the west but reaches the blueschist-facies to the east. Structures related to four phases of deformation are identified. The first two generations of structures (D1–D2), related to the original top-to-the-west nappe stacking, are associated with conditions close to the peak of Alpine metamorphism. Previous tectonic surfaces are transposed by the dominant deformation structures (D3), developed under retrograde/decompression conditions. This D3 corresponds to a backfolding and back-thrusting event with a top-to-the-E transport. A fourth phase (D4) developed during late low-grade metamorphic conditions and deforms the previous surfaces by locally developing a crenulation cleavage, followed by brittle tectonics. An updated metamorphic map is presented, backed on published estimates and new thermometric data obtained by Raman Spectroscopy of Carbonaceous Material (RSCM). The TRSCM values range from ~ 295 °C to > 350 °C, moving from the most external Briançonnais unit to the internal Queyras "Schistes Lustrés" units. Suspected Upper Cretaceous palaeofaults have been documented, allowing us to group the classic Aiguille de Mary and Ceillac (sub-) units into a single tectonic unit, here referred to as Maurin unit. The palaeogeographical reconstruction of the evolution of the studied transect highlights the importance of the Marinet and Maurin axial units in the feeding of the Late Cretaceous-Eocene breccias deposited on the more internal Acceglio-type units. [ABSTRACT FROM AUTHOR]

We demonstrate, with examples from the Chřiby Highlands (Western Carpathian Flysch Belt, WCFB), that the fractured Flysch rocks here manifest higher landslide susceptibility than is commonly seen in comparable bedrock. The Chřiby Highlands represent the NE border of the Vienna Basin which developed from the Middle Miocene up to the Pleistocene as part of sinistral strike-slip movements. These last tectonic movements were followed by the post-thrusting phase as documented by the Pliocene and the Pleistocene sedimentation, and the presence of neotectonic faults. We mapped the landslides using digital elevation models and conducted field mapping. Information on recent sedimentation was obtained from unpublished borehole data available in the archive of the Czech Geological Survey. We determine that the NE part of the Chřiby Highlands has higher landslide density (11.85%) than the SW part (6.62%). The landslide density in the NE part is also higher than any previously published data from areas of a comparable size in the WCFB. It was not possible to detect all the landslides during field mapping because Quaternary loess covers some parts of the study area. We found three loess-covered landslides based on borehole data analysis. They are of Pleistocene age and rank among the oldest indirectly dated landslides in the entire WCFB. We conclude that Flysch rock fracturing, caused by both old (Oligocene–Lower Miocene) and neotectonic (Middle Miocene to Pleistocene) fault activities, induce deep rock weathering and consequently increased the susceptibility of flysch rock to landslides. [ABSTRACT FROM AUTHOR]

Flysch formations are widespread all around the Mediterranean basin and in many other parts of the world. Their special fabric, characterized by a strong heterogeneity due to alternations of often deformed lapideous and fine-grained layers and by a network of discontinuities, brings to light the strong limitations of the geo-engineering sciences when dealing with such complex materials. Based on the results of an investigation carried out in a long section of the Southern Apennines, the paper examines this problem focusing in particular on the role played by material fabric at different scales on the hydraulic and mechanical behavior of the deposit. Highlights: The mechanical behaviour of the Red Flysch formation is carefully analysed with a particular attention to the influence of the soil fabric at different scales. The Red Flysch formation is described within the frame of the structurally complex formations The results of a wide in situ and laboratory investigation on a Red Fysch deposit are collected and interpreted The role played by material fabric at different scales on the hydraulic and mechanical behavior of the deposit is evidenced. The strong limitations of the geo-engineering sciences when dealing with such complex materials are highlighted [ABSTRACT FROM AUTHOR]

The Adria-derived Drina-Ivanjica Unit of the Internal Dinarides represents a composite basement-cover thrust sheet passively carrying obducted Jurassic ophiolites and post-obduction Upper Cretaceous sedimentary rocks, penetrated by post-orogenic Miocene igneous rocks. This study presents the first paleomagnetic results from the Drina-Ivanjica Unit obtained at a total of 34 geographically distributed localities, representing Triassic-Jurassic carbonates, Upper Cretaceous carbonate and flysch successions, as well as Miocene igneous rocks. Paleomagnetic directions for the igneous rocks and the Upper Cretaceous flysch, which had clearly remagnetized during Miocene magmatism, point to a 30° clockwise (CW) rotation, which must have taken place after 20 Ma. This angle perfectly agrees with the earlier-published value for both the Western and Eastern Vardar zones (including the Jadar-Kopaonik thrust sheet, the Sava Zone, and the Cretaceous overstepping sequence of the Eastern Vardar ophiolitic unit), suggesting a coordinated rotation between them and the Drina-Ivanjica Unit. Results of the present study set a younger age constraint (20 Ma) for the commencement of the coordinated CW rotation instead of the previously suggested 23 Ma. The rotation may have connected to the extension induced by the slab rollback of the Carpathians, which was also responsible for the opening of the Pannonian Basin. The paleomagnetic directions for the Cenomanian-Turonian carbonates, which are situated far from the magmatic bodies, are interpreted in terms of a minor counter-clockwise (CCW) rotation taking place before the Miocene CW rotation. The Triassic-Jurassic carbonates of the Drina-Ivanjica Unit have post-tilting magnetizations, which were likely induced by the thermal effect of the obducted ophiolites. The overall mean paleomagnetic direction suggests a rotation of about 50° CCW between 150-20 Ma, which is in line with the well-documented post-150 Ma CCW rotation of the Adriatic microplate. [ABSTRACT FROM AUTHOR]

This study demonstrates the effectiveness of sedimentological–statistical multivariate analysis of one‐dimensional‐section in the unravelling depositional processes and sedimentation patterns recorded in a contained and partially ponded succession. Turbidite deposition of a 100 m thick mud‐rich Oligocene‐age sequence at Szczawa, the Polish Outer Carpathians, was primarily controlled by topographic confinement and magnitude of incoming flows. Only the largest turbidite flows were subjected to the true flow ponding, while in smaller volume flows the silty/sandy part behaved as unconfined flow and only muddy suspension cloud developed a ponded character. True ponding of low‐density turbidity currents is interpreted for sandstones that show sedimentary structures attesting to flow reflections and combined‐flow processes, and are associated with abnormally thick co‐genetic mudstones, which in turn results in low sandstone‐to‐mudstone ratio, irrespective of turbidite bed thickness. These features testify to pronounced interaction of flows with confining topography. Tractional structures associated with a considerable proportion of fines, namely banded structure and heterolithic bedding, are interpreted as produced during transitional (turbulent to laminar) flow phase in the condition of mud‐rich turbidite flow confinement. These structures are also considered here as indicators of proximity to source area and location on the slope. The co‐occurrence of banded sandstones, hybrid event megabeds and an olistostrome resulted from flows‐trapping, confined basin geometry, which precluded downslope propagation and further transformation of large‐volume flows. Therefore, a structurally‐controlled contained intraslope mini‐basin is proposed here as the most likely depositional setting. This work provides robust field and statistical evidence for ponding processes of low‐density turbidity currents in a structurally‐controlled mini‐basin. The results of this study are consistent with experimental data and recent field studies on ponded turbidites. Therefore, the Szczawa succession may serve as a new reference example of containment processes of low‐density turbidity currents and represents a valuable depositional model for intraslope turbidite succession. [ABSTRACT FROM AUTHOR]

DNA barcoding represents a handy tool for species identification. In addition, it serves as a complementary approach that improves the characterisation of evolutionary lineages and facilitates the detection of potentially undescribed and cryptic species. Based on the case study in the Western Carpathians, which belong to the Carpathian biodiversity hotspot, we have compiled the first DNA barcode reference library for molecular identification of invertebrates associated with epikarst, a unique, yet understudied, shallow subterranean aquatic habitat that extends at the interface between the soil and carbonate rocks. We analysed invertebrates collected in 2019-2020 from epikarst water that continuously seeps into four caves of the Demänovský Cave System in northern Slovakia. The standard barcode marker of the mitochondrial COI gene was amplified in more than 920 individuals of aquatic, semi-aquatic, and terrestrial invertebrates. The final data set consisted of 784 barcode sequences representing 36 morphospecies, the majority (98.3%) belonging to Arthropoda. Automated cluster delineation using the Barcode of Life Data System (BOLD) revealed 60 Barcode Index Numbers (BINs), of which 43 BINs were new to BOLD, representing mostly typical subterranean species. Almost 20% of the morphospecies displayed high intraspecific variation (>2.2%), suggesting the need for further investigation to assess potential taxonomic problems or cryptic diversity. Our results also indicated the existence of several yet undescribed invertebrate species and possible heteroplasmy or COI numts in the collembolan Megalothorax sp. (incertus species group). The resulting DNA barcode library represents a significant advance not only in the characterisation of epikarst biodiversity but also in the understanding of subterranean biodiversity in general, paving the way for future complex evolutionary and biogeographical studies. [ABSTRACT FROM AUTHOR]

The exhumed Infrahelvetic Flysch Units in the eastern central Alps in Switzerland are a field analog to modern accretionary wedges at active plate boundaries. In these seismically active convergent settings, water‐saturated sediments undergo consolidation, and diagenetic to low‐grade metamorphic processes cause complex fluid‐rock interactions. To contribute to the understanding of structural and fluid processes and their interaction with seismic activity, we present quantitative information on the geometrical and spatial distribution of slate‐hosted calcite veins from the Infrahelvetic Flysch Units that show mutual overprinting relationships with the ductile phyllosilicate‐rich matrix. Two vein systems that form in the deeper part of the inner wedge are characterized: (a) layer‐parallel veins (meter‐scale) forming spatially repetitive vein‐arrays and (b) pervasively distributed, steep micron‐veinlets, that cross‐cut the thicker layer‐parallel veins and the ductile matrix. Synchrotron X‐ray Fluorescence Microscopy (XFM) is instrumental in detecting previously unseen densely spaced micron‐veinlets. The spatial distribution of micron‐veinlets indicates pervasive layer‐perpendicular fluid transport in response to dissolution‐precipitation creep through the wedge. Layer‐parallel veins form vein‐arrays with thicknesses on the meter‐scale suggesting that fluids are progressively localized in channels up‐scale. Both vein sets form in an alternating fashion with two different enhanced flux directions, which could be indicative for a critically stressed wedge with near‐lithostatic fluid pressures. The layer‐parallel veins and vein‐arrays could represent seismic events with low magnitude earthquakes (Mw up to 4.0) or slow‐slip events currently found at active plate boundaries, while micron‐veinlets and dissolution‐precipitation processes accommodate slow interseismic deformation. Plain Language Summary: Convergent plate boundaries are locations where lithospheric plates collide. Plate collision produces a wide variety of seismic activity, which is a major natural hazard posing socio‐economic risks. When oceanic plates are involved in collision, an accretionary wedge made of sediments forms near the plate boundary. Here, we study an ancient accretionary wedge in the Swiss Alps to examine the potential traces of paleo‐seismic activity left in the rock record. We focus on ubiquitous veins, mineralized fractures that acted as fluid pathways in such active seismic domains. We documented veins from the field (m‐scale) to the grain scale (μm‐scale). Synchrotron X‐ray Fluorescence Microscopy (XFM) enabled mapping of trace‐element concentrations in the vein minerals, capturing tracers of paleo‐fluid transport at 2 μm resolution. The innovative XFM technique unveiled the presence of micron‐veinlets with widths less than that of a human hair. These micron‐veinlets form widespread, densely spaced clusters throughout these rock sequences. Our microanalytical observations demonstrate that these micron‐veinlets facilitate fluid transport via dissolution‐precipitation creep during interseismic deformation of the wedge while the m‐scale veins could potentially represent small earthquakes or slow slip events. Key Points: Cyclic fracturing, veining, and pressure solution are characteristic in the sediment‐rich inner part (>250°C) of the accretionary wedgeSynchrotron XFM documents pervasive micron‐veinlets enabling layer‐perpendicular fluid migration during slow wedge deformationLayer‐parallel veins arrange in vein‐arrays indicating localized fluid transport and potentially small seismic or slow‐slip events [ABSTRACT FROM AUTHOR]

Heterogeneous rock masses that include rhythmic alternations of marl, shale, marly limestone, sandstone, siltstone, and argillite, such as Flysch, are particularly prone to generating colluvial deposits on gentle slopes, which are often subject to failures triggered by heavy rainfall. Flysch-derived colluvial soils are made up of highly heterogeneous sediments ranging from clayey loam to rock fragments, and they have been studied more rarely than homogeneous soils. In this work, we present a geotechnical and hydraulic characterisation performed both in situ and in the laboratory on flysch-derived colluvial soils that were involved in a channelised landslide in the pre-alpine area of the Friuli Venezia Giulia region (NE Italy). The investigated soils were characterised by the average values of the grain size composition of about 25% gravel, 20% sand, 30% silt, and 25% clay. The loamy matrix presented low-to-medium values of the liquid and plastic limits, as well as of the plasticity index (LL = 40%, PL = 23%, and PI = 17%, respectively). The values of the peak friction angle for natural intact samples were 33° < ϕ’p < 38°, whereas the residual friction angle fell to 23–24° at great depths and high vertical stresses, for a prevailing silty–clayey matrix. Variable head permeability tests were performed both in situ and in the laboratory, showing that the values of the vertical and horizontal permeability were very close and in the range 1 × 10−4–1 × 10−6 m/s. The soil permeability measured in the field was generally higher than the hydraulic conductivity calculated on laboratory samples. The proposed geotechnical and hydrological characterisation of flysch-derived colluvial soils can be of fundamental importance before the use of more thorough analyses/models aimed at forecasting the possible occurrence of slope failures and evaluating the related landslide hazard. The reported geotechnical and hydraulic parameters of flysch-derived colluvial materials can represent a useful reference for rainfall infiltration modelling and slope stability analyses of colluvial covers that are subject to intense and/or prolonged precipitation. However, when facing engineering problems involving colluvial soils, particularly those coming from flysch rock masses, the intrinsic variability in their grain size composition, consistency, and plasticity characteristics is a key feature and attention should be paid to the proper assumption of the corresponding geotechnical and hydraulic parameters.

ABSTRACTBadlands are specific landforms characterized by intense denudation processes. Their occurrence is mainly associated with clay-like materials and semi-arid and Mediterranean climates. This study presents the badland inventory for the Paleogene Pazin Basin located on the Istrian peninsula in Croatia. A total of 5,381 badland polygons, with a total area of 10.25 km2, were manually outlined, based on the visual interpretation of orthophotos at a scale of 1:5,000. The badlands in Istria are represented as small and isolated landforms and are exclusively associated with flysch and flysch-like materials, which cover a significant part of the study area (46%). The analysis of badland inventory shows that badlands are spatially not equally distributed but that their abundance is increasing from NW to SE part of the analyzed area. Additionally, the results of the spatial analysis indicate the positive relationship between badland occurrence and relative relief, which is presented via the relief-badland index.