Magura Nappe Research Articles

Comparison of MASW and seismic interferometry with use of ambient noise for estimation of S-wave velocity field in landslide subsurface

This study presents a comparison of data acquisition, processing and interpretation between passive seismic interferometry (SI) and active multichannel analysis of surface waves (MASW) methods, both using surface waves for estimation S-wave velocity field. Measurements have been taken in the same geological engineering conditions on Just-Tegoborze landslide on the south of Poland. This comparison study has an important meaning from landslide hazard evaluation point of view. The landslide is located in Magura Nappe in Outer (Flysch) Carpathians. SI was based on registration of local seismic noise generated by high traffic on the state road which intersects the landslide. The main processing step was cross-correlation of seismic noise between every pair of receivers. It led to obtain series of empirical Green’s functions for Rayleigh surface wave. However, in MASW method, seismic energy was released by an impact of 5 kg sledgehammer in a metal plate. Both methods included analysis of dispersion curves of Rayleigh surface wave. The inversion of picked fundamental modes was applied using genetic algorithm and resulted in 1D S-wave velocity models. The last step of interpretation included model visualization as the 2D S-wave velocity sections for studied profiles. Both MASW and SI methods allowed to estimate S-wave velocity field in Just-Tegoborze landslide subsurface. Dispersion images obtained from both methods provided similar phase velocity and frequency ranges. On S-wave velocity sections, the greater depth range was observed for SI method; however, lateral resolution was better for MASW. Slip surfaces in colluvial layer were not observed on either SI or MASW S-wave velocity sections. Only results obtained from SI allowed to distinguish probable slip surface located deeper, i.e. on the contact with less weathered flysch bedrock.

Depositional systems and paleogeography of Upper Cretaceous-Paleogene deep-sea flysch deposits of the Magura Basin (Western Carpathians)

The Outer Western Carpathians are part of the Alpine-Himalayan orogenic belt, and they are formed mostly by the Upper Cretaceous and Paleogene deep-sea “flysch” sequences. Orava region (northern Slovakia), situated in the central part of the Magura Nappe, has an important position for the solution of the geological structure and development of the Magura Nappe. At the beginning of the research, determination of the sedimentary sequences of the Magura Nappe and the fundamental lithotypes and lithofacies was required. A total of 1164 paleocurrent measurements were measured and assigned to lithotypes and lithostratigraphic units obtained during the detailed sedimentological study. The main purpose of the research was the interpretation of the filling history and tectonic activity of the Magura Basin. The results of the detailed sedimentological study were integrated with published data from surrounding regions. Presented palinspastic maps propose a reconstruction of the filling history and tectonic activity in chronological order during the Upper Cretaceous to Oligocene. Maps focus in detail on the western part of the Magura Basin, but they display its surroundings as well. The sedimentary record reflects the activity and gradual shifting of the Western Carpathian accretionary wedge to the north, the uplift of source areas, and the changes in the sea level of the Magura Basin. The paleocurrent analyses joined with the sedimentological and petrographic research allowed to reconstruct the paleogeographic properties of the northern sources of detritic material (Hostýn, Fore-Magura and Silesian Ridges), of the southern source of the material (Western Carpathians accretionary wedge) and of intrabasinal sources as well (Szczawina and Southern-Magura Ridges). We propose a discussion about the character of filling history, defining and position of the source areas and about Hostýn Ridge defined here.

Neoproterozoic crystalline exotic clasts in the Polish Outer Carpathian flysch: remnants of the Proto-Carpathian continent?

Crystalline exotic boulders within the sedimentary sequences of the Outer Carpathians likely represent Proto-Carpathian basement, which was exposed and eroded during the Mesozoic and Cenozoic evolution of the Western Carpathian basin. The majority of the boulders were derived from the Silesian Ridge, which separated the Magura Basin and the Silesian Domains, and which became a source region during Late Cretaceous–Early Paleocene tectonism. Felsic crystalline clasts within the Silesian Nappe yield U–Pb zircon magmatic protolith ages of 603.7 ± 3.8 Ma and 617.5 ± 5.2 Ma while felsic crystalline clasts within the Subsilesian Nappe yield an age of 565.9 ± 3.1 Ma and thus represent different magmatic cycles. The U–Pb zircon data also imply that the Silesian Ridge was a fragment of the eastern part of the Brunovistulia microcontinent. The presence of inherited zircon cores, dated at 1.3 and 1.7 Ga, suggests a Baltican source for the clasts, as opposed to Gondwana. We infer that Late Neoproterozoic felsic magmatism within the Proto-Carpathian continent represents a long-living magmatic arc, which formed during prolonged Timmanian/Baikalian rather than Pan-African/Cadomian orogenesis. Mafic exotic blocks, found within the Magura Nappe, yield U–Pb zircon ages of 613.3 ± 2.6 Ma and 614.6 ± 2.5 Ma and likely represent a fragment of an obducted ophiolitic sequence. The protolith of these mafic boulders could represent Paleoasian Ocean floor located to the east of Cadomia, obducted during later orogenic processes and incorporated into the accretionary prism. All analysed exotic clasts show no evidence for younger (Variscan) reworking, which is characteristic of both western Brunovistulia and the Central Western Carpathians and the Cadomian elements of Western Europe. The Silesian and Subsilesian basins thus had a likely source area in the eastern part of Brunovistulia, while the source of the Magura Basin was the Fore-Magura Ridge, whose basement potentially represents an accretionary prism on the margin of the East European Craton.

Comparison analysis of numerically calculated slip surfaces with measured S-wave velocity field for Just-Tęgoborze landslide in Carpathian flysch

The article presents the comparison analysis between deformation field from numerical model and shear wave (S-wave) velocity field obtained from seismic interferometry (SI). Tests were conducted on active Just-Tęgoborze landslide. Geologically, the study area lies in Magura Nappe in the Outer Carpathians. The landslide’s flysch bedrock is covered by Quaternary colluvium built of clays and weathered clayey-rock deposits. During geotechnical investigation, properties of landslide body were established and failure surfaces were distinguished. In order to obtain S-wave velocity models, one-hour of ambient seismic noise was recorded by 12 broadband seismometers. As a result of data processing with SI method, Rayleigh surface wave propagation was reconstructed. The analysis of dispersion curves allowed to estimate a two dimensional S-wave velocity field. The deformation field were calculated assuming an elastic-plastic Coulomb-Mohr strength criterion. Images of shear strain increment, and values of factor of safety of the slope were obtained as a result of calculation. The comparison of the results indicates the similar characteristic features in the S-wave velocity field and the field of deformation calculated numerically.

The Jurassic to Palaeogene strata in the northern boundary fault zone in deep borehole PD-9 at Szczawnica, Pieniny Klippen Belt, West Carpathians, Poland: biostratigraphy and tectonic implications

The Jurassic through Palaeogene stratigraphy and tectonic structure of the PD-9 borehole at Szczawnica, Pieniny Klippen Belt, West Carpathians, Poland, is revised. The borehole was drilled in the strongly tectonized northern boundary fault zone of the Pieniny Klippen Belt, of Miocene age. Age revision is given by dinoflagellate cysts. Late Cretaceous taxa are reported from the Haluszowa Formation. The Bryjarka Member (previously with the rank of formation) yielded rich Early Eocene (Ypresian) assemblages. Similar ones are reported from the Szczawnica Formation. A tectonic thrust sheet of the Jurassic Szlachtowa Formation (Grajcarek Unit) in the Palaeogene of the Magura Nappe is evidenced; it yielded late Toarcian–Aalenian dinoflagellate cyst assemblages. The succession of strata recorded from the PD-9 borehole shows the steep, almost vertical attitude of the Grajcarek Main Dislocation at Szczawnica, separating the structures of the Magura Nappe (to the north) and the Pieniny Klippen Belt to the south.

The Early Miocene residual flysch basin at the front of the Central Western Carpathians and its palaeogeographic implications (Magura Nappe, Poland)

In the Polish sector of the Magura Nappe, along the front of the Pieniny Klippen Belt, strongly tectonized calcareous flysch up to 1000 m thick is exposed. Previously these deposits, composed of thin- to thick-bedded flysch, with a packet of Łącko-type marls, have been included into several Paleocene/Eocene formations, e.g., the Szczawnica Formation. This formation contains a poor assemblage of agglutinated foraminifera and a relatively rich assemblage of calcareous nannoplankton, with abundant reworked species. The youngest species give evidence of the NN2 Zone (Lower Miocene). Additionally, in three profiles (Szlachtowa, Knurow and Waksmund) of the Kremna Fm., Early Miocene foraminifera have been recognized. This research documented that during the Burdigalian, at the front of Central Western Carpathians, there still existed a residual marine basin probably up to 100 km wide. These deposits also contain thick packages of exotic carbonate conglomerates derived from the SE, previously regarded as the Jarmuta Formation.

The genesis of the carbon dioxide in the Polish Outer Carpathians : Szczawa tectonic window case study : new insight

In the Polish sector of the Magura Nappe have long been known and exploited carbonate mineral waters, saturated with carbon dioxide, known as the “shchava (szczawa)”. These waters occur mainly in the Krynica Subunit of the Magura Nappe, between the Dunajec and Poprad rivers, close to the Pieniny Klippen Belt (PKB). The origin of these waters is still not clear, this applies to both “volcanic” and “metamorphic” hypotheses. Bearing in mind the case found in the Szczawa tectonic window and our geological and geochemical studies we suggest that the origin of the carbon dioxide may be linked with the thermal/pressure alteration of organic matter of the Oligocene deposits from the Grybow Unit. These deposits, exposed in several tectonic windows of the Magura Nappe, are characterized by the presence of highly matured organic matter – the origin of the hydrocarbon accumulations. This is supported by the present-day state of organic geochemistry studies of the Carpathian oil and gas bed rocks. In our opinion origin of the carbon-dioxide was related to the southern, deep buried periphery of the Carpathian Oil and Gas Province. The present day distribution of the carbonated mineral water springs has been related to the post-orogenic uplift and erosion of the Outer (flysch) Carpathians.

The \u0160ari\u0161 Transitional Zone, revealing interactions between Pieniny Klippen Belt, Outer Carpathians and European platform

The Pieniny Klippen Belt (PKB) is a narrow structure delineating the boundary between the Central and Outer Carpathians. It is built of nappes stacked during the Cretaceous and Paleocene and then re-folded in the Miocene during the formation of the Outer Carpathian overthrusts. The internal structure of the PKB at the Polish/Slovakian border first formed during northward nappe thrusting processes, which were most intense at the turn of the Cretaceous to the Paleocene. A secondary factor is the change in strike of the PKB turning from W–E to WNW–ESE, associated with dextral strike-slip faulting in the Carpathian basement (North-European Platform). These NNW-SSE oriented strike-slip fault zones, broadly parallel to the Teisseyre-Tornquist Zone, are responsible for the segmentation of the down-going plate, which influenced the subduction and collision between the North-European Platform and the Central Carpathian Block. Among them, the most important role was played by the Kraków—Myszków Fault Zone separating the Małopolska and Upper Silesian blocks in the Carpathian foreland. Shifts and interactions between the neighboring Pieniny and Outer Carpathian basins—during contemporaneous sedimentation and deformation—resulted in a difficult-to-define, transitional zone. Until now this zone had the rank of a tectonic unit, named “Grajcarek Unit” in Poland and “Šariš Unit” in the Slovak Republic. However, its northern boundary, often taken to represent the Central/Outer Carpathians boundary, is ambiguous. These problems are due to the spatial overlap of thrusting and gravitational flows resulting in chaotic breccias, olistoliths and olistostrome formation, which formed repeatedly and became deformed during the Maastrichtian to Early Miocene. Tectonic deformations in this area gradually vanished towards the north. This zone can therefore be defined as the Peri-Klippen part of the Magura Nappe that lacks a distinct northern tectonic limit. For this reason it is named Šariš Transitional Zone (ŠTZ).

Potential source rocks in the Ropianka Formation of the Magura Nappe (Outer Carpathians, Poland) – geochemical and foraminiferal case study

To optimize exploration for new hydrocarbon accumulations in the Polish Outer Carpathians, it is necessary to concentrate attention on identification of hydrocarbon accumulations of the “shale-gas” type. Results of recently completed analysis suggested new such possible targets in the Magura Basin, preserved in the Outer Carpathian Magura Nappe. Analysis of the preliminary results of paleoenvironmental and geochemical studies of these shales is the subject of this paper. Micropaleontological and geochemical study was conducted on the 300 m thick Świątkowa Member, the uppermost part of the Ropianka Formation located in the external, northernmost Siary Zone. This member is composed of thin- and medium-bedded sandstones interbedded by green, brown, black and dark-gray shales. Poor and changeable oxygenation is reflected in the composition of foraminiferal assemblages. A negative correlation between the TOC content and numbers and diversity of foraminifera is observed. The paleogeographic position and paleoenvironment assessment indicates that the Siary Zone fulfills certain conditions for organic productivity and preservation during the deposition of the Ropianka Formation.

The tectonics and stratigraphy of the transitional zone between the Pieniny Klippen Belt and Magura Nappe (Szczawnica area, Poland)

The Pieniny Klippen Belt is a narrow, complex structure stretching along a tectonic boundary between the Central and Outer Carpathians. Its formation involved two main evolutionary stages, the first, related to Late Cretaceous-Paleocene folding and thrusting, and the second, associated with Miocene orogenic events in the Outer Carpathians. Interactions between the Pieniny Klippen Belt and Outer Carpathians during both the sedimentation and deformation stages have resulted in the establishment of a peri-klippen transitional zone (named the Saris Transitional Zone), in which the tectonic deformation effects gradually decrease towards the north. The stratigraphy and tectonic position of this zone have been controversial for decades. The key stratigraphic problems concern 1) the lithologic identity and position of the Szlachtowa (“black flysch”), Opaleniec and Pieniny formations and 2) the relation of the Jarmuta Formation, associated mainly with the Saris Transitional Zone, to the Szczawnica and Zarzecze formations of the Magura Nappe. We provide an early Paleogene dinoflagellate cyst stratigraphic record of deposits that, according to some recent reinterpretations, represent the Neogene “Kremna Formation”. The legitimacy of new lithostratigraphic assignments of the “Kremna Formation” at Jaworki is put into question upon the basis of the primacy of units introduced for the same strata earlier.

Sedimentary response to tectonic uplift of the Dukla basin margin recorded at Skrzydlna – the Menilite Beds (Oligocene), Outer Carpathians, S Poland

The Menilite Beds (Oligocene of Polish Flysch Carpathians) at Skrzydlna crops out in a structurally complex zone of the Fore-Magura Unit, which is tectonically overridden by Magura Nappe thrust form the S. The exposed sedimentary suite, representing the Dukla Basin, consists of fine-grained, well organised strata deposited in a low-energy, deep marine basin, which are abruptly overlain by poorly organised, coarse sandy conglomerate that forms a Mass Transport Deposit (MTD) complex. The MTD contains large boulders of extrabasinal rocks, massive sandstone beds with intrabasinal mudstone clasts, and slump sheets of sandstones. Above rests a fining- upwards sequence of sandstone beds interlayered with mudstones. The fine-grained facies reappear above to terminate the exposed succession. Erosional contacts and rapid facies changes, both vertical and lateral, are characteristic for the MTD unit. The sandstone-mudstone unit above contains laterally migrating erosional channels filled with massive sandy conglomerate in the lower part. Turbidites of varying density and completeness of internal structures that occur above are accompanied by an association of mixed facies including large-scale dune cross-bedding. Mineralogically, the sandstones are quartz arenites, sub-lithic arenites and wackes. Calcarenite grains – bioclasts, micrite and marl occur in substantial proportions only in the uppermost part of the succession. The point-counting data plotted on Qm-F-Lt diagram are clustered within the recycled fields: quartzose and transitional. Mineralogical maturity of the sandstones has the tendency to decrease from the sub-MTD strata upwards via the MTD unit to the lower part of the sandstone-mudstone complex; then it increases to the youngest sandstone beds with carbonate grains. These tendencies, associated with sedimentary features of the succession, reflect rapid uplift, emergence and progressive erosion of the terrigenous detritus source area, followed by tectonic stabilisation reflected by the appearance of the “carbonate factory”.

Heavy minerals and exotic pebbles from the Eocene flysch deposits of the Magura Nappe (Outer Western Carpathians, eastern Slovakia): their composition and implications on the provenance

The study aims to reconstruct the crystalline parent rock assemblages of the Eocene Strihovce Formation (Krynica Unit) and Mrazovce Member (Raca Unit) deposits, based on the heavy mineral suites, their corrosive features, geochemistry of garnet and tourmaline, zircon cathodoluminescence (CL) images, and exotic pebble composition. Both units are an integral part of the Magura Nappe belonging to the Flysch Belt (Outer Western Carpathians). Corrosion signs observable on heavy minerals point to different burial conditions and/or diverse sources. The compositions of the detrital garnets and tourmalines as well as the CL study of zircons indicate their origin in gneisses, mica schists, amphibolites, and granites in the source area. According to observed petrographic and mineralogical characteristics, palaeoflow data and palaeogeographical situation during the Eocene may show that the Tisza Mega-Unit crystalline complexes including a segment of the flysch substratum could represent the lateral (southern) input of detritus for the Krynica Unit. The Raca Unit might have been fed from the northern source formed by the unpreserved Silesian Ridge. The Marmarosh Massif (coupled with the Fore-Marmarosh Suture Zone) is promoted to be a longitudinal source.

The Ropianka Formation of the Bystrica Zone (Magura Nappe, Outer Carpathians): proposal for a new reference section in northwestern Orava

The thin- and medium-bedded, turbiditic deposits that are exposed in the Bystrica Zone of the Magura Nappe in the Slovak Orava region are the subject of this study. On the basis of lithological features as well as age and stratigraphic position, they are assigned to the Ropianka Formation. The very well exposed rocks of this formation, recognized in the Biela Farma profile in the Slovak part of the northwestern Orava region, are compared with analogous deposits in the Polish Orava and the Beskid Wysoki Mountains. Lithological and biostratigraphical documentation of the Ropianka Formation is presented. This documentation allowed the determination of the age of the rocks studied. Abundant and taxonomically diverse foraminiferal assemblages of agglutinated, benthonic and occasional planktonic forms indicate a Middle Paleocene age for the upper part of the Ropianka Fm. A new stratigraphic position for the Szczawina Sandstone, considered to be a member of the Ropianka Fm, is proposed. The lithostratigraphy of the Ropianka Fm in the Magura Nappe in Poland, Slovakia and the Czech Republic requires further investigation, including the establishment of new type and reference sections. The large outcrop at Biela Farma should be taken into consideration as a potential reference section. Studies of the new sections will lead to a new monographic elaboration of the Ropianka Fm in Poland, Slovakia and the Czech Republic.

Geology of the Magura Nappe in the Osielec area with emphasis on an Eocene olistostrome with metabasite olistoliths (Outer Carpathians, Poland)

The Magura Nappe in the Polish sector of the Outer Carpathians consists of four tectonic subunits characterized by differing development of facies. From the south to the north, they include the Siary, Raca, Bystrica and Krynica subunits. The sedimentary succession in the Raca Subunit in the vicinity of the village of Osielec is composed of Campanian–Palaeogene flysch deposited in the Magura Basin. In this succession, the Middle Eocene Pasierbiec Sandstone Fm consists of thick-bedded sandstones and conglomerates with occasional intercalations of thin-bedded shale-sandstone flysch. Within the Pasierbiec Sandstone Fm at Osielec there is an olistostrome, rich in pebbles and cobbles of exotic rocks. In addition, large blocks of Neoproterozoic metabasites and boulders of Palaeogene organogenic limestones were found. The discovery of metabasites raised the possibility that the rocks in question could be evidence of supposed oceanic crust in the basement of the Magura sedimentary basin, because of the suggestion that they represent the Alpine orogenic cycle. This concept was abandoned when investigations of the absolute age of the metabasites gave a date of ca. 600 Ma. In the Osielec area, there are two tectonic thrust sheets in the Raca Subunit, namely the Osielczyk Thrust Sheet in the north and the Bystra Thrust Sheet in the south; they are folded and cut by a transverse system of strike-slip and oblique faults. The Osielczyk Thrust Sheet was overthrust northwards on to the Siary Subunit.

The Grajcarek Succession (Lower Jurassic–mid Paleocene) in the Pieniny Klippen Belt, West Carpathians, Poland: a stratigraphic synthesis

A concise stratigraphic synthesis of the Grajcarek Succession of the Pieniny Klippen Belt (West Carpathians,Poland) is presented. This succession consists of 12 lithostratigraphic units with the rank of formation, and two with the rank of member, spanning the geological time from middle Toarcian (late Early Jurassic) to Maastrichtian (Late Cretaceous) and mid Paleocene. The stratigraphical column starts with deep-water flysch (the Szlachtowa Fm; Toarcian–Aalenian through Bajocian–?lower Bathonian), followed by dysoxic shales, marls and limestones (the Opaleniec Fm; Bajocian–Bathonian). The previously distinguished Krzonowe and Stembrow formations, are downgraded to members. Late Bathonian–Oxfordian times were characterized by the widely occurring deposition of abyssal radiolarites and shales, which is represented by the Sokolica Radiolarite Fm and the Czajakowa Radiolarite Fm, common to both the Grajcarek and Klippen successions. Red nodular limestones and aptychus marls (the Czorsztyn Limestone Fm; Kimmeridgian–lower Tithonian) overlie the radiolarites. Above, pelagic cherty limestones occur (the Pieniny Limestone Fm; Tithonian–Aptian). These are followed by Lower Cretaceous predominantly dark shales and marls (the Kapuśnica Fm; Aptian–Albian, the Wronine Fm; Albian, and the Hulina Fm; Albian–Cenomanian), succeeded by abyssal, red shales (the Malinowa Shale Fm; upper Cenomanian–Campanian), and these in turn by grey, marly, flyschoid strata (the Haluszowa Fm; ?Campanian). The Grajcarek Succession terminates with the Jarmuta Fm (Maastrichtian–mid Paleocene). It consists of sedimentary breccias, often with large olistoliths of Jurassic–Cretaceous rocks, and conglomerates and sandstones in a southern zone, giving way to proximal flysch and distal flysch facies further north. This was the time of orogenic Laramian folding events, associated with subaerial and submarine erosion. A sedimentary hiatus separates the Jarmuta Fm flysch (Maastrichtian) from the Szczawnica Fm (Upper Paleocene–Eocene) in both the Klippen and Grajcarek successions. This hiatus seems to diminish and finally close in a northward direction, in the Magura Nappe succession.

Chromian spinels from the Magura Unit (Western Carpathians, Eastern Slovakia) – their petrogenetic and palaeogeographic implications

Detrital chromian spinels in sedimentary rocks provide much information concerning the tectonics of their parental ultrabasic rocks. Chromian spinels occurring in the Eocene to Oligocene deposits from the Magura Nappe were examined to provide some constraints on the history of the Magura Basin. The Magura Nappe is a part of the Flysch Belt belonging to the External Western Carpathians. The Magura Nappe is separated by a narrow zone associated with the Pieniny Klippen Belt and is divided into three principal tectono-lithofacies units (from the S to N): the Krynica, Bystrica and Rača units. Cr-spinel is a common accessory mineral (2.3–5.9 vol% of heavy mineral spectra) in the siliciclastic rocks of the Rača and Krynica units. In terms of texture and chemical composition, two types of Cr-spinels were recognized: unaltered and altered. Unaltered spinels were found to contain silicate inclusions such as chromio-pargasite, enstatite, diopside, pargasite, plagioclase and olivine (forsterite). The chromian spinels show wide variations in compositional parameters such as Cr# (0.3–0.7), Mg# (0.3–0.7), TiO2 (<0.03–1.9 wt.%) and Fe 2+ /Fe 3+ (2.5–13) whereas the differences between the Rača and Krynica units are insignificant. These parameters suggest a peridotitic and volcanic origin of the spinels, respectively. The ophiolite source consisting of harzburgitic mantle peridotites was developed mainly in a supra-subduction zone setting; volcanic spinels indicate an origin in mid-ocean ridge basalts, back-arc basin basalts and sporadically in ocean-island basalts. Concerning their geochemical features, we propose that during the Eocene to Early Oligocene, the ophiolitic detritus in the eastern part of the Magura Basin deposits may have been derived from a source area located in the Fore-Marmarosh Suture Zone (Eastern Carpathians) that is considered an equivalent of the Black Flysch and Ceahlau units. Some Cr-spinels found in the Eocene sedimentary successions may have resedimented from older Late Cretaceous-Paleocene formations of the Magura Unit, which are considered as reworked sedimentary material from the Pieniny Klippen Belt.

Age and provenance of mica-schist pebbles from the Eocene conglomerates of the Tylicz and Krynica Zone (Magura Nappe, Outer Flysch Carpathians)

Abstract During the Łate Cretaceous to Palaeogene, the Magura Basin was supplied by clastic material from source areas situated on the northern and southern margins of the basin, which do not outcrop on the surface at present. The northern source area is traditionally connected with the Silesian Ridge, whereas the position of the southern one is still under discussion. A source area situated SE of the Magura Basin supplied the Eocene pebbly para-conglomerates containing partly exotic material. The studied clastic material contains fragments of crystalline rocks, and frequent clasts of Mesozoic to Palaeogene deep and shallow-water limestones. Numerous mica schists, scarce volcanites and granitoids as well as gneisses, quartzites and cataclasites were found in the group of crystalline exotic pebbles. Monazite ages of “exotic” mica-schist pebbles from the Tylicz, Zarzecze and Piwniczna-Mniszek sections document the Variscan 310±10 Ma age of metamorphic processes. The provenance of these exotic rocks could be connected with a remote source area located SE of the Magura Basin, which could be the NW part of the Dacia Mega Unit. The idea is strongly supported by palaeotransport directions from the SE, the absence of material derived from the Pieniny Klippen Belt, the presence of shallow water limestones, typical facies of the Median Dacides belt and metamorphic age distribution proved by monazite dating.

Heavy minerals from sedimentary rocks of the Malcov Formation and their palaeogeographic implications for evolution of the Magura Basin (Western Carpathians, Slovakia) during the Late Eocene – Late Oligocene

Detrital heavy minerals separated from the Malcov Fm. deposits (Magura Nappe) indicate their source rocks and areas. The heavy mineral assemblages predominantly consist of garnet, zircon, tourmaline, rutile and Cr-spinel. EPMA analyses reveal a few groups of garnets: zoned and unzoned Grs almandines, Prp-Sps almandines, unzoned Prp almandines, almandines, Sps almandines and rare zoned spessartine grains (~85 mol% Sps). The garnet composition indicates that gneisses, mica schists, amphibolites and granites were their main source rocks, but low-grade metapelites with Mn mineralisation probably contributed as well. The detrital dravitic tourmalines were mostly derived from paragneisses and mica schists. Cr-spinel indicates a volcanic source. Based on heavy mineral assemblages, coupled with palaeoflow analysis, we conclude that the Marmarosh Massif and Fore-Marmarosh Suture are the most probable source areas. Aditionally, the Malcov sedimentary basin was supplied by material from the crystalline complexes of the Tisza Mega-Unit and Pieniny Klippen Belt (PKB). The bulk of the clastic deposits comprise classical turbidites. These lithofacies were deposited from either turbidity currents or from concentrated density flows. The palaeoflow record is varied and highlights the contribution of sedimentary material from several directions and/or diversion of gravity currents from the main flow direction (SE–NW). The marginal parts of the Malcov sub-basins were formed of deformed and uplifted older formations of surrounding units of the Magura Nappe and PKB (submerged ridges). Older (Late Cretaceous to Eocene) flysch sediments may have been redeposited from these ridges to neighbouring sub-basins in a transverse direction (NE–SW).

Early Miocene age of the Stare Bystre Formation based on calcareous nannofossils (Magura Nappe, Outer Carpathians, Poland)

The area of investigation is situated close to the contact zone between the Pieniny Klippen Belt, Krynica Subunit of the Magura Nappe and the Neogene strata of the Orava–Nowy Targ Intramontane Basin (southern Poland). In the area studied, marine deposits of the Stare Bystre Formation outcrop at the surface where they emerge from beneath freshwater and terrestrial Neogene and Quaternary deposits. Nannofossil assemblages from all samples are strongly dominated by reworked species. The Early Miocene age (NN2) of the Stare Bystre Formation has been determined on the base of the first occurrence of Sphenolithus disbelemnos after Shackleton et al. (2000). During the Late Oligocene (NP25/NN1), the frontal part of Magura Nappe was thrust northwards on to the terminal Krosno flysch basin. The northwards thrusting of the Magura Nappe was accompanied by the formation of the piggy-back basin on the Magura Nappe, filled with the synrorogenic turbidites belonging to the Zawada, Kremna and Stare Bystre formations (NN2).

Calcareous nannofossils and foraminifera from the youngest deposits of the Siary Subunit (Oligocene, Magura Nappe, Polish Outer Carpathians)

The calcareous nannoplankton and foraminifera from the Gladyszow Beds, regarded as the youngest deposits in the northern marginal Siary Subunit of the Magura Nappe in Poland, are characterized. The material investigated comes from outcrops in the vicinity of Gladyszow and from the Gladyszow PIG-1 borehole. The analysis allowed the establishment of the age of these deposits as not older than late Rupelian–early Chattian (the calcareous nannoplankton NP24 Zone). The taxonomic affiliations, environmental associations and preservation of the microfossils were analyzed to document the sedimentary processes and environmental conditions during the geotectonic transformation of the Magura Basin in the Oligocene. These microfossils also were compared with those reported from the terminal deposits of the Outer Carpathians and the Podhale Basin.