Outer Carpathians Research Articles

Dinoflagellate cyst biostratigraphy of Upper Cretaceous turbiditic deposits from a part of the Bąkowiec section in the Skole Nappe (Outer Carpathians, southern Poland)

Dinoflagellate cysts from turbiditic deposits of the Ropianka Formation in an interval of the Bąkowiec section (Skole Nappe, Outer Carpathians, southern Poland) have been analyzed. This interval, previously attributed to the Cretaceous–Paleogene boundary transition based on planktic and benthic foraminifera, contains organic-walled dinoflagellate cysts (dinocysts) of a latest Campanian age. The difference in age, revealed here between foraminifera and dinocyst findings, is considered as an unresolved dilemma, which is pending some explanations, probably on the basis of further multidisciplinary studies envisaged in the same outcrop. The palynological content is well preserved and rich in dinocyst cyst taxa, including 37 upper Campanian index species among 92 species in total. The dinocyst assemblages observed in this interval are similar to those previously recognized in biostratigraphically well-calibrated sections of Western Europe. The dinocyst marker events enabled a correlation of the studied interval with the Samlandia mayi dinocyst Zone of Slimani (2001a), which is an equivalent to the Belemnitella minor Zone in the northwestern Europe. These dinocyst events include the first occurrences (FOs) of Kleithriasphaeridium truncatum, Nematosphaeropsi philippotii, Samlandia carnarvonensis, Samlandia mayi and last occurrences (LOs) of Corradinisphaeridium horridum, Raetiadinium truncigerum, Odontochitina operculata and Xenascus ceratioides subsp. ceratioides. The palynological content shows significant reworking of Campanian dinocyst taxa and a richness in palynodebris of continental origin, which are likely related to deposition by turbiditic currents.

The Occurrence of Skeletons of Silicoflagellata and Other Siliceous Bioparticles in Floral Honeys.

Siliceous marine microfossils were unexpectedly discovered during the analysis of flower honey samples from Poland and Tunisia. The microfossils were represented by protist with siliceous skeletons: silicoflagellates, diatoms, and endoskeletal dinoflagellates. This is the first record of such microfossils in honeys. Based on the high percent of anemophilous pollen grains and spores in the sample, it was hypothesized that silicoflagellates were deposited from the air onto the nectariferous flowers, then bees harvested them with the nectar. Based on the comparison of pollen content of honeys and flowering calendar of Tunisia, the harvest time of honey was identified as a period between 1 April and 31 May 2011. Trajectory analysis of air masses in this period confirmed that siliceous microfossils could be aerosolized by wind from the rocks of the so-called Tripoli Formation of Messinian age (6–7 Ma). Similar to the Tunisian case, the Polish trajectory simulation also supports the hypothesis of atmospheric transport of silicoflagellates from outcrops of Oligocene age in the Polish Outer Carpathians. In the case of diatom content of honey, however, the source can be both natural (wind) and artificial (diatomaceous earth filters). For a correct determination, natural sources of siliceous bioparticles, such as wind transport from nearby outcrops should be also considered. Silicoflagellates could be used as complementary indicators of the geographical origin of honeys collected in areas characterized by diatomite outcrops, supporting the results obtained with other methods; thus, such indicators merit further studies within the area of honey authenticity.

A lost carbonate platform deciphered from clasts embedded in flysch: Štramberk-type limestones, Polish Outer Carpathians

Limestones designated the Štramberk-type are the most common carbonate exotic clasts (exotics) embedded in the uppermost Jurassic–Miocene flysch deposits of the Polish Outer Carpathians. About 80% of stratigraphically determinable carbonate exotics from the Silesian, Sub-Silesian and Skole units (nappes) are of Tithonian (mostly)–Berriasian (sporadically Valanginian) age. A study of these exotics revealed eight main facies types: coral-microbial boundstones (FT 1), microencruster-microbial-cement boundstones (FT 2), microbial and microbial-sponge boundstones (FT 3), detrital limestones (FT 4), foraminiferal-algal limestones (FT 5), peloidalbioclastic limestones (FT 6), ooid grainstones (FT 7), and mudstones-wackestones with calpionellids (FT 8). Štramberk-type limestones in Poland and the better known Štramberk Limestone in the Czech Republic are remnants of lost carbonate platforms, collectively designated the Štramberk Carbonate Platform. Narrow platforms were developed on intra-basinal, structural highs (some of them are generalized as the Silesian Ridge), with their morphology determined by Late Jurassic synsedimentary tectonics. An attempt was made to reconstruct the facies distribution on the Tithonian–earliest Cretaceous carbonate platform. In the inner platform, coral-microbial patch-reefs (FT 1) grew, while the upper slope of the platform was the depositional setting for the microencruster-microbial-cement boundstones (FT 2). Microbial and microbial-sponge boundstones (FT 3), analogous to the Oxfordian–Kimmeridgian boundstones of the northern Tethyan shelf (also present among exotics), were developed in a deeper setting. In the inner, open part of the platform, foraminiferal-algal limestones (FT 5) and peloidal-bioclastic limestones (FT 6) were deposited. Poorly sorted, detrital limestones (FT 4), including clastsupported breccias, were formed mainly in a peri-reefal environment and on the margin of the platform, in a high-energy setting. Ooid grainstones (FT 7), rarely represented in the exotics, were formed on the platform margin. Mudstones-wackestones with calpionellids (FT 8) were deposited in a deeper part of the platform slope and/or in a basinal setting. In tectonic grabens, between ridges with attached carbonate platforms, sedimentation of the pelagic (analogous to FT 8) and allodapic (“pre-flysch”) Cieszyn Limestone Formation took place. The most common facies are FT 4 and FT 1. Sedimentation on the Štramberk Carbonate Platform terminated in the earliest Cretaceous, when the platform was destroyed and drowned. It is recorded in a few exotics as thin, neptunian dykes (and large dykes in the Štramberk Limestone), filled with dark, deep-water limestones. Reefal facies of the Štramberk Carbonate Platform share similarities in several respects (e.g., the presence of the microencrustermicrobial-cement boundstones) with reefs of other intra-Tethyan carbonate platforms, but clearly differ from palaeogeographically close reefs and coral-bearing facies of the epicontinental Tethyan shelf (e.g., coeval limestones from the subsurface of the Carpathian Foredeep and the Lublin Upland in Poland; the Ernstbrunn Limestone in Austria and Czech Republic). Corals in the Štramberk Limestone and Štramberk-type limestones are the world’s most diverse coral assemblages of the Jurassic–Cretaceous transition. The intra-basinal ridge (ridges), traditionally called the Silesian Cordillera, which evolved through time from an emerged part of the Upper Silesian Massif to an accretionary prism, formed the most important provenance area for carbonate exotic clasts in the flysch of the Silesian Series. They are especially common in the Lower Cretaceous Hradiště Formation and the Upper Cretaceous–Paleocene Istebna Formation. The Baška-Inwałd Ridge and the Sub-Silesian Ridge were the source areas for clasts from the Silesian and Sub-Silesian units (e.g., in the Hradiště Formation), while the Northern (Marginal) Ridge was the source for clasts from the Skole Unit (e.g., in the Maastrichtian–Paleocene Ropianka Formation).

Тектоно-седиментаційна еволюція передової частини насувної споруди Українських Карпат

For the first time in the Ukrainian Carpathians, the depths and tectono-sedimentation processes in the north-eastern part of the Outer Carpathian Basin (Skyba and Boryslav-Pokuttya units) have been restored on the base of sedimentological and microfaunistic studies. It was established that in the Cretaceous-Eocene time, the deep-water (near Calcite Compensation Depth) turbidite and similar sedimentation (turbidites with Bouma textures, grainites, debris-flow deposits), which periodically alternated with (hemi)pelagic sedimentation (red, green and black shales) was dominant here. Sedimentation took place on the continental margin of the the Carpathian branch of the Tethys, where deep-water fans were formed. Cretaceous-Eocene background red and green shales are enriched in buried in situ benthic foraminifera which are similar in taxonomic composition and morphological features to the microfauna of the Carpathian-Alpine and Atlantic regions (deep-water agglutinated foraminifera), which indicate lower bathyal – abyssal depths of flysch sedimentation. Latest Eocene Globigerina Marl horizon contains the foraminiferal assemblage with plankton dominance, which indicates a general shallowing of the Outer Carpathian Basin (middle-upper bathyal conditions above a calcite compensation depth). Oligocene – lowermost Miocene Menilite-Krosno and Polyanytsia formations were accumulated in the Skyba and Boryslav-Pokuttya sub-basins. In the Miocene, shallow-water molasses were accumulated here. Probably, the tectonic uproot of flysch deposits from its substrate and their synsedymentary thrusting towards the platform caused a significant shallowing of the Skyba and Boryslav-Pokuttya sub-basins starting from the latest Eocene. These processes reflected the growth of the Carpathian frontal nappes at the final orogen formation stage.

Sedimentology of the Godula Formation in the Moravskoslezské Beskydy Mts. (Outer Western Carpathians, Czech Republic)

The present account summarizes the results of lithological and facies analysis of representative sections of the Godula Formation, in order to contribute to the understanding of the lithofacies structure of this formation, the processes involved in its development and the character of the depositional environment. The sedimentology of different parts of the Godula Formation was investigated in six representative sections in the western and central parts of the Moravskoslezske Beskydy Mts. The Godula Formation is made up mainly of Upper Cretaceous siliciclastic turbidites and was formed during the most significant depositional phase of the filling of the deep-sea Silesian Basin. On the basis of sedimentological research, five facies classes (including four subclasses) were defined: 1) conglomeratic sandstones, 2) sandstones, 3) sandstones with mudstones, 4) mudstones with sandstones and siltstones, and 5) mudstones with siltstones. The methodology of facies analysis allowed the identification of several facies association, corresponding to the medial and distal parts of a turbidite fan and associated siliciclastic apron. The facies of depositional lobes, lobe transitions and the apron are described. The sandstone and mudstone facies (F3) occurs mostly in the depositional lobes. The sandstone facies (F2) and mudstone with sandstone and siltstone facies (F4) are present only to a lesser degree. The facies of the lobe transitions include lithologic associations of the lobe fringe and channel levee environments. They comprise mainly the mudstones with sandstones and siltstones (F4) and the mudstone with siltstone facies (F5). In the apron deposits, the sandstone facies (F2) and the conglomeratic sandstone facies (F1) predominate. Palaeocurrent analysis from measurements made in selected profiles showed that in the Moravskoslezske Beskydy Mts., the dominant direction of sediment transport was from SW to NE. After applying correction of the known counterclockwise rotation of the nappes of the Outer Carpathians, this corresponds to a longitudinal direction along the original axis of the basin.

Paleoenvironment, Organic Matter Maturity and the Hydrocarbon Potential Of Menilite Shales (Silesian Unit, Polish Outer Carpathians) – Organic and Inorganic Geochemical Proxies

Paleoenvironment, Organic Matter Maturity and the Hydrocarbon Potential Of Menilite Shales (Silesian Unit, Polish Outer Carpathians) – Organic and Inorganic Geochemical Proxies

A novel VRo, Tmax, and S indices conversion formulae on data from the fold-and-thrust belt of the Western Outer Carpathians (Poland)

Results are presented on the relationships between the vitrinite reflectance VRo, the Tmax temperatures determined with Rock-Eval pyrolysis, and the smectite (S) indices representing the percentage of smectite in the mixed-layer illite-smectite (I/S) from claystones. Samples locations are recovered from the Polish part of the Outer Carpathian fold-and-thrust belt. Organic indices show thermal maturities of most outcrop samples in the range of 0.47 to 1.49% Ro and 421 to 485 °C Tmax. Inorganic S indices values range from 8 to 60%. Lateral variability of the maturity measured with both organic and inorganic indices reflects mainly differences of maximum tectonic burial in the accretionary prism and subsequent exhumation and denudation. For the Western Outer Carpathians the calculated formulae for Tmax to VRo and S to VRo conversion are VRo = 0.0152 * Tmax - 5.938 (r2 = 0.87) and VRo = 1.1432–0.01295 * S (r2 = 0.65), respectively. Maximum paleotemperatures were calculated for individual samples from S indices by applying the novel formula T = ln (1.1432–0.01295 * S) + 1.68/0.0124. The proposed new conversion formulae might be useful in other regions with a similar geological setting, i.e. for claystone formations dominated by kerogen type III in fold–and-thrust belts, characterized by rapid tectonic burial accompanied by a low geothermal gradient, as well as maturities of the sub-bituminous to the medium volatile bituminous rank (0.5 to 1.50% Ro).

Sedimentological and geochemical characteristics of the Lower Krosno Beds from the Gorlice fold and the Stróże Thrust Sheet (Silesian Unit, Polish Outer Carpathians)

Praca prezentuje sedymentologiczną i geochemiczną charakterystykę warstw krośnieńskich z fałdu Gorlic oraz łuski Stróż. Na podstawie prac terenowych wykonano dwa profile: Stróże o miąższości rzeczywistej 300 m oraz Lipinki o miąższości rzeczywistej 227 m. W ich obrębie rozpoznano 9 facji osadowych, które zostały w pracy opisane i zinterpretowane pod kątem mechanizmów depozycji. Zidentyfikowano i opisano występujące w profilach struktury sedymentacyjne, w tym ważne dla określania środowiska sedymentacji: kopułowe warstwowanie przekątne (HCS) oraz rynnowe warstwowanie przekątne. Zestawiono razem profile terenowe oraz krzywe geofizyki wiertniczej z otworów Gorlice-12 oraz L-OU1. Dane te poddano wzajemnej korelacji, co pozwoliło na wskazanie podobieństw w wykształceniu litologicznym w profilach z fałdu Gorlic oraz różnic w stosunku do profilu z łuski Stróż. Do badań geochemicznych pobrano 8 prób skał mułowcowo-ilastych (profil Stróże – 3 próbki: S5–S7, profil Lipinki – 5 próbek: L3–L8), które poddano analizie geochemicznej opartej na biomarkerach. Badania biomarkerów pozwoliły na uszczegółowienie typu materii organicznej, pośrednio na wskazanie warunków, w jakich dochodziło do jej akumulacji, oraz na potwierdzenie bakteryjnego pochodzenia związków. Zidentyfikowano arylowe izoprenoidy (krótko- i średniołańcuchowe), wyższe diarylowe izoprenoidy oraz wyższe aromatyczne karotenoidy C40, takie jak: izorenieratan, β-paleorenieratan, β-izorenieratan, β-renierapurpuran, chlorobaktan czy okenan. Obliczono wskaźniki arylowo-izoprenoidowy AIR oraz izorenieratan/fenantren, które pozwalają na określenie środowiska sedymentacji. Przebadano próbki pod kątem: charakteru środowiska sedymentacji, w tym fotycznej strefy anoksycznej (PZA) i czasu jej trwania, głębokości chemokliny i zbiornika, działalności bakteryjnej podczas sedymentacji. Wyniki analiz próbek wykorzystanych w niniejszej pracy porównano z archiwalnymi wynikami analiz próbek z obszaru fałdu Gorlic.

Stratigraphy and paleogeographic environments for the forming the Carpian Series (Stryi and Opir River basins, Ukrainian Carpathians)

Results of studying the Carpian Series – a component of the thick Lower Cretaceous-Miocene flysch of the Outer (Flysch) Carpathians are presented in the article. Sediments of the Carpian Series (Middle Paleocene – Eocene) were studied in the Skole Beskids in the basin of the middle and lower reaches of the river Opir in the area of conducting geological and geographical educational practices of students of Ukrainian universities. Using the method of sedimentological analysis, it was found that the investigated sediments are the product of the activity of gravitational flows (mainly turbidites, as well as grainites, debrites), bottom currents and background hemipelagic sedimentation. These sediments are compared with the facies of deep-marine fans placed on the continental slope and its foot. Medium- and coarse-grained turbidites and grainites (Yamna and Vyhoda formations) correspond to the submarine valley-channel facies. Fine- and medium-grained turbidites and hemipelagites (Manyava and Bystrytsa formations) belong to the inter-channel facies. The composition of the clastic material (green and red phyllites) suggests, that the sediments were drifted from the Eurasian continental margin into the deep-marine fan (fans?). Applying the micropaleontological method, it was established that the Paleocene-Eocene background red and green clay hemipelagites are enriched in buried in situ benthic foraminifera (deep-water agglutinated foraminifera: DWAF), which indicate lower bathyal – abyssal depths of flysch accumulation below a calcite compensation depth (CCD). Late Eocene calcareous lithofacies of the Popiele Formation contain a mixed foraminifera assemblage formed as a result of mud and debris flows. Shallow-water fauna and “exotic” debris (including the red and green phyllites) were transferred from the shelf area to the deep basin. The Latest Eocene hemipelagic clay-carbonate sediments of the Sheshorian horizon contain the foraminiferal assemblage with plankton dominance, which indicates a general shallowing of the paleobasin (middle-upper bathyal conditions above a calcite compensation depth) at the end of the Carpian time. Key words: stratigraphy, paleogeography, Ukrainian Outer Carpathians, Paleocene-Eocene flysch, turbidites, foraminifera.

Additional data on post-Paleozoic sea-lilies (Crinoidea, Echinodermata) from the Outer Carpathians of the Czech Republic and Poland

Jurassic (Tithonian) and Lower Cretaceous (Berriasian/Valanginian-Hauterivian) strata of the Vendryně and Cieszyn Limestones formations in the Czech Republic and Poland are locally rich in crinoid remains, consisting of whole cups, isolated cup elements, brachial plates, columnals and pluricolumnals, cirrals, and holdfasts. They are assigned to isocrinids (Isocrinida: Isocrinus cf. amblyscalaris, Isocrinida indet.), cyrtocrinids (Cyrtocrinida: Eugeniacrinites sp., Phyllocrinus sp., Gammarocrinites sp., Hemicrinus tithonicus, Plicatocrinus hexagonus, Cyrtocrinida indet.), millericrinids (Millericrinida: Millericrinida indet.), and thiolliericrinids (Comatulida, Thiolliericrinidae: Thiolliericrinidae gen. et sp. indet.). Late Cretaceous (Maastrichtian) and Paleogene (Paleocene-Oligocene) crinoids from the Subsilesian Unit are recorded as individual remains belonging to: Isocrinida indet., Cyrtocrinida indet., bourgueticrinids (Comatulida, Bourgueticrinina: Bourgueticrinina fam. et gen. indet.) and roveacrinids (Roveacrinida, Roveacrinidae gen. et sp. indet.). Roveacrinids were retrieved only from Maastrichtian samples. Despite the conclusions previously presented that isocrinids of the Outer Flysch Carpathians dominated around the Jurassic-Cretaceous boundary due to the very shallow sedimentary environment of these strata, we can now conclude that they were common and associated with cyrtocrinids in all types of environments. It is also worth mentioning that cyrtocrinids and isocrinids occur in Paleogene sediments that were deposited in extremely shallow environments. On the other hand, many literature data suggested that Cretaceous (by mid-Cretaceous) isocrinids migrated to deep-water areas, as a response to an increase in the number of predators during the so-called Mesozoic marine revolution.

Active faulting and seismic hazard in the Outer Western Carpathians (Polish Galicia): Evidence from fractured Quaternary gravels

This report opens a new window on Quaternary tectonics of the Outer Western Carpathians. We discuss results of fractured clasts analysis in Quaternary fluvial gravels within a 4.500 km2 large area comprising a part of the Outer Carpathians including Nowy Sącz Intramontane Basin (NSIB) as well as in the innermost part of the Carpathian Foredeep. Quaternary gravels bearing fractured clasts are widespread within the area, we observed them in 180 exposures. In the Carpathian Foredeep and in the Outer Carpathians excluding the NSIB, the exposures of gravels bearing fractured clasts are located largely close to (<2 km) all major overthrusts and close to (<0.75 km) the cross-fold faults of the Skawa River Fault System (SRFS). The clast-cutting fractures are mostly joints attesting to widespread Quaternary tectonic activity of the faults. Moreover, the density of occurrence of gravels bearing fractured clasts is considerably higher within the NSIB than in other parts of the study area. Furthermore, our results shed new light on the seismic hazard in the study area. In our interpretation, the clast-cutting fractures are damage resulting from coseismic rupturing of underlying bedrock faults or from regional seismic shaking. We conclude that in the study area the seismic hazard posed by natural seismicity can matter only in case of planning there the erection of critical structures like nuclear power plants, nuclear waste repositories or gas storage facilities. On the other hand, we infer that the appreciable seismic hazard is near the cross-fold faults of the SRFS, due to the location of Świnna Poręba Artificial Lake there, which can lead to triggering significant seismicity in the area. Furthermore, we suggest that fractured clasts can serve worldwide as providers of information on paleoseismicity and can be useful for mapping blind faults.

Assessment of tectonic control on the development of low mountains moderate relief in the Outer Carpathians (Southern Poland)

Inherited tectonic structures, ongoing tectonic deformation, and variations in relative rock uplift rates play an important role in conditioning the processes of relief development. Their influence among other factors, such as climate and lithology, can be quantified using landscape analysis, and geomorphometric indices, in particular. The usage of landscape analysis in recent years is increasing systematically due to the constant improvement of the digital elevation models and GIS software that significantly facilitate this approach. In this study, we aim to recognize the influence of tectonic structures and processes on relief development in the low mountains with moderate relief of the Soła River catchment in the Western Outer Carpathians. To this end, we calculated geomorphometric indices (river longitudinal profile, stream-length gradient index, minimum bulk erosion, relief ratio, circulatory ratio, elongation ratio, and hypsometric integral) for the Sola River and its 47 sub-catchments using a 25-m spatial resolution Digital Terrain Elevation Data Level 2. Additionally, we identified lineaments and knickpoints and correlated the computed results with local and regional fault networks, variations in lithology, and climate fluctuations. Obtained results indicate a significant impact of inherited tectonic structures on the relief development of the Soła River catchment, i.e., directions of principal ridges and valleys follow the orientation of main folds and faults recorded in this area. Anomalously high values of minimum bulk erosion, river gradient, and stream-length gradient index allowed us to define two areas with higher relative uplift rates: 1) the Sola Gorge and 2) the Beskid Żywiecki Mts. Polish Outer Carpathians are generally considered as an area of low strain rate and low seismic activity. However, the possibility of neotectonic processes should be considered in geohazard estimations. Observed bends in the direction of river valleys that do not correspond with changes in lithology could be related to active strike-slip faults. These are probably the reactivated basement structures, copied in the thin-skinned nappe cover, as a result of the accommodation of the Mur-Žilina Fault Zone resulting from the tectonic push of the Alcapa (Alpine-Carpathian-Pannonian) microplate against the European plate. Thus, the role of recent tectonic activity in relief development of the Sola River catchment even though appears to be subsidiary at the most, should not be excluded.

Geological setting and lithological inventory of the Czarna Woda conglomerates (Magura Nappe, Polish Outer Carpathians)

During the late Oligocene to early Miocene the residual Magura Basin was located along the front of the Pieniny Klippen Belt (PKB). This basin was supplied with clastic material derived from a south-eastern direction. In the Małe (Little) Pieniny Mts. in Poland, the late Oligocene/ early Miocene Kremna Fm. of the Magura Nappe (Krynica subunit) occurs both in front of the PKB as well as in the tectonic windows within the PKB. Lenses of exotic conglomerates in the Kremna Fm. contain frequent clasts of Mesozoic limestones (e.g. limestones with “filaments” microfacies and Urgonian limestones) and Eocene shallow-water limestones. Fragments of crystalline and volcanic rocks occur subordinately. The provenance of these exotic rocks could be probably connected with Eocene exhumation and erosion of the SE part of the Dacia and Tisza Mega-Units.

Post-IR IRSL dating the oldest (?) river terrace sediments in the Polish Outer Carpathians: Insights into the landscape evolution

Post-infrared infrared stimulated luminescence (post-IR IRSL or pIRIR) was applied to determine the age of the highest-elevated alluvial sediments in the Polish Outer Carpathians. These sediments are preserved on the western slope of the Dunajec River valley, and are located 150–155 m above the present-day river channel. So far, they have been interpreted as accumulated during the Praetiglian (2.58–2.40 Ma). The pIRIR ages, however, indicate that the sediments were deposited ~2 Ma later. Such results incorporate an important record of river system evolution which has been developing very dynamically since the time of the sediment accommodation. The determined ages introduce average rate of river incision which can be calculated as 0.48–0.50 mm a−1 since the last ~309 ka. This implies that the river section has been fairly tectonically uplifting and brings attention to the rates of uplift in the rest part of the Polish Outer Carpathians. Also, adopting results from the former dating campaign, it is clear that relics of Pleistocene alluvial sediments are predominantly of cold-climate origin, and a scenario for this style of sediment preservation is proposed.

Geometry and topology of tectonolineaments in the Gorce Mts. (Outer Carpathians) in Poland

The present study was focused on analysis of the geometrical and topological features of the lineament network in the Gorce Mountains, Polish Outer Carpathians. The source data was a 1m high-resolution LiDAR digital elevation model (DEM). Network topology was analysed using the NetworkGT toolset for ArcGIS software. The topological analysis represented the first attempt to apply research of this type in the Polish Carpathians. Five lithostratigraphic units occurring in the research area, characteristic of the Krynica Zone of the Magura Nappe, were selected for analysis. Topology was studied for each of the units separately as well as for the whole area. It was found that the units were differentiated in terms of some topological parameters, such as 2D intensity. Moreover, latitudinal trends were observed due to the presence of wide fault zones. The geometry of the network is consistent with the general Carpathian overview. Sets of conjugate strike slip-faults with splaying ends were identified. In the southern part of the area, the strike of the oldest faults was E-W. This shows that on the scale of the observation (hundreds to thousands of metres), the network was a product of general thrusting processes rather than derivative of a local structural plan. The applicability of both topological analyses and high-resolution DEM as supplementary to classical methods in a study of the Outer Carpathians was confirmed with analysis conducted, despite the identification of some limitations, such as GIS-operator-related bias. The scale of the analyses is linked, in a multi-scale approach, to structural network analyses.

RomUkrSeis: Seismic model of the crust and upper mantle across the Eastern Carpathians – From the Apuseni Mountains to the Ukrainian Shield

RomUkrSeis is a controlled source wide-angle reflection and refraction (WARR) profile acquired in August 2014. It is 675 km long, running roughly SW-NE from the Apuseni Mountains in Romania and the Transylvanian Basin, crossing the arc of the Eastern Carpathian orogen and terminating in the East European Craton (EEC) in SW Ukraine. Well-constrained 2-D ray-tracing P- and partly S-wave velocity models have been constructed along the profile from 348 single-component seismic recorders and eleven shot points. The Eastern Carpathian arc formed in the Cenozoic and have obscured the pre-existing Teisseyre-Tornquist Zone (TTZ), which is a transition zone between the Precambrian EEC and continental terranes accreted to it from the southwest in the Palaeozoic. The TTZ is characterised by low-velocity through its entire crust (6.0–6.3 km/s) and a considerable width (~140 km). It is interpreted as EEC crust stretched during rifting and continental margin formation in the Neoproterozoic and early Palaeozoic. The crust of the TTZ has a “trough in trough” structure wherein an upper body of ~40 km width comprising Outer Carpathian (Vp 4.9 km/s) and Late Palaeozoic-Mesozoic (Vp 5.4 km/s) units to 15 km depth lies above a wider, deeper one of inferred Neoproterozoic-early Palaeozoic strata. The crust of the Transylvanian Basin and Apuseni Mountains is relatively thin (~32 km). A high-velocity body at 4–12 km depth in this area is interpreted as a rootless fragment of an ophiolite complex exposed at the surface in this area. The lower crust beneath the Transylvanian Basin displays higher velocities than adjacent segments. Moho topography is strongly differentiated along the profile, varying from 32 to 50 km. The Moho shape, especially in the area between the Inner and Outer Carpathians, suggests a NE dip and, hence, thrusting of the Tisza-Dacia lowermost crustal and upper mantle units under the TTZ domain which, in turn, could be thrust under the cratonic (EEC) block.

Origin, secondary processes and migration of oil and natural gas in the central part of the Polish Outer Carpathians

The origin, migration pathways, and the influence of secondary processes of oil and natural gas accumulated in Lower Cretaceous to Lower Miocene strata of the central part of the Polish Outer Carpathians are investigated based on organic geochemical analyses. Oil and thermogenic hydrocarbon gases were mainly generated from both types II and III kerogens in the Oligocene Menilite beds of the Silesian, Skole and Dukla nappes. Moreover, some gases originated from Type III kerogen of Lower Cretaceous Veřovice shales in the Silesian Nappe and Lower Cretaceous Spas shales in the Skole Nappe. These gases migrated and subsequently mixed with oil and gas produced from Type II kerogen in the Menilite beds. The most extensive biodegradation and water washing were observed in oils from Harklowa and Iwonicz fields, and in oil from the BF (Franek) dug-well in Bóbrka-Rogi field (one of the world's oldest with exploitation started in 1854) of the Silesian Nappe. Oils most affected by evaporative fractionation come from Krościenko and Iwonicz Zdrój fields. Natural gas originated mainly from low-mature thermogenic processes (“oil window”) with some primary microbial gas contribution (primary carbon dioxide reduction), and many gas samples show secondary alteration caused by biodegradation. Carbon dioxide originated from both thermogenic kerogen decarboxylation and microbial processes.

Slope destabilization provoked by dissociation of gas hydrates in the Outer Carpathian basin during the Oligocene: Sedimentological, petrographic, isotopic and biostratigraphic record

Sedimentological, biostratigraphic, petrographic, and stable C and O isotope study was carried out on chaotic complexes hosting carbonate concretions in the uppermost Oligocene successions of the Outer Carpathians. These chaotic complexes reveal a range of sedimentary features indicative of intrabasinal, submarine mass-wasting deposition, including soft-sediment deformation, brecciation, homogenization and fluidization of the parent material. Apart from carbonate concretions, they enclose blocks of rocks having lithologies typical for the underlying Oligocene strata. The concretions exhibit extremely depleted δ13C (by down to −51.3‰) indicating anaerobic oxidation of methane, whereas their δ18O values are strongly enriched relative to coeval brackish basin water indicating dissociation of gas hydrates as the main fluid source. These data and the geotectonic context imply that the chaotic complexes formed as submarine slumps on a N-inclined paleoslope of the basin in consequence to tectonically-induced dissociation of gas hydrates. Hydrates were destabilized within the sediments due to synorogenic uplift, related to northward progradation of the accretionary prism. These slumps and hosted concretions were dated by the combination of calcareous nannoplankton and organic-walled dinoflagellate cysts. The age of concretions indicated by dinoflagellate cyst assemblages always overlaps with that of the surrounding slump matrix determined by both micropaleontological groups. Together with sedimentological and petrographic evidence, this confirms that the concretions formed in situ within the sediment shortly after deposition and prior to slumping. Hydrate dissociation, seepage of methane-charged fluids and the resultant slope destabilization was not an isolated event, but a continuous process occurring diachronously in front of N-prograding accretionary prism during Oligocene, at least from early NP23 to late NP25 biozones.The stable C and O isotope analysis of carbonate concretions was crucial for this research, because the low δ13C and high δ18O values were the only preserved indicators of anaerobic oxidation of methane and dissociation of gas hydrates in the basin, respectively. Because, the concretions are composed of a mixture of dolomite and calcite, a semiautomatic method for measuring C and O isotope composition selectively for calcite and dolomite (Baudrand et al., 2012) was applied, which provided conclusive results. These measurements were combined with detailed petrographic investigations, which enabled assessment of isotopic composition for various carbonate constituents separately, e.g. sedimentary calcite (biogenic and detrital), early and late calcite cements, dolomite cement. They showed that the concretionary microcrystalline calcite was the main cement that precipitated due to hydrate dissociation and subsequent methane oxidation. This approach can provide valuable information when applied to other authigenic carbonates composed of a mixture of dolomite and calcite.

Biostratinomy and Diagenetic Impact on Exceptional Preservation of Coccospheres from Lower Oligocene Coccolith Limestones

Lower Oligocene coccolith limestones, known as Tylawa Limestones, in the Polish part of the Outer Carpathians have been analyzed using back-scattered electron (BSE) and charge contrast imaging (CCI) techniques and X-ray diffraction. The aim of the study was to reconstruct the fossilization history of the excellently preserved coccospheres, commonly observed in these sediments, deposited in the Paratethys basin. Multiple petrographic and geochemical analyses indicate that the exceptional preservation of coccospheres has been caused by the special coincidence of biostratinomic processes: pre- and post-depositional processes within the water–sediment interface and possible early cementation. We discuss the origin of the calcite and silica and provide some hypotheses regarding the environment and possible factors responsible for the spectacular preservation process. Based on the observed intermediate steps of calcite and silica alteration, we propose an extended model of biostratinomic processes and diagenesis. The possibility of finding exquisitely preserved coccospheres not only in soft clay-rich deposits but also in heavily lithified rocks extends the possibilities of research on the development and evolution of this group of organisms.

Reconstruction of landslide movements using Digital Elevation Model and Electrical Resistivity Tomography analysis in the Polish Outer Carpathians

Landslides are a major threat to the environment, infrastructure and human activities, especially in mountainous and hilly areas. It is therefore important to accurately identify the mass movements triggering these mechanisms. This paper presents the impacts of lithotectonic conditions on the formation of mass movements on the example of the landslide that is located in the northern part of the Polish Outer Carpathians. In the area of the research, the ratio of the total area of landslides to the surface of the area reaches even 20%. The interpretation of a high resolution Digital Elevation Model (DEM), Electrical Resistivity Tomography (ERT) and fieldwork results allowed for the reconstruction of the landslide movements and dividing them into two areas; the western one, dominated by rotational movement, and the eastern one, featuring rotational and translational movement. It was found that the eastern part is more active now as it probably was also in the past, which might have resulted from the lithotectonic conditioned or from the impact of the flowing waters of the Dunajec River. Moreover, in the eastern part of the landslides, a small-sized ridge (55 m × 25 m) was identified, which shows greater stability in comparison with the colluvium that surrounds it. In order to explain the lower rate of movement of this landform, a morphometric analysis and research using ERT were performed. The geophysical measurements showed that the ridge comprised rock formations of greater resistivity than its surroundings. It is most likely that the only preserved sandstone packet, constituting the original secondary escarpment, became separated from the bedrock due to rotational movement. The presented studies indicate that the landslide was created due to geological and atmospheric conditions. A clear revival of landslide movements took place after significant precipitation events that last occurred in the years 2010 and 2015. The bedrock substrate due to its lithology and tectonics, facilitates these movements. It was found that the landslide studied is a complex entity, characteristic of the Polish Outer Carpathians, that has undergone multiple stages of development. The landslide is active or periodically active and, therefore, must be excluded from the planned development as well as from other forms of human activity.