Flysch Belt Research Articles

Is Cr-Spinel Geochemistry Enough for Solving the Provenance Dilemma? Case Study from the Palaeogene Sandstones of the Western Carpathians (Eastern Slovakia)

The provenance of the Proč and Strihovce sandstones is crucial for understanding the relationship between the Pieniny Klippen (PKB) and Flysch (FB) belts in the easternmost part of the Western Carpathian realm. Detrital Cr-spinels in these tectonic units were assertively interpreted as sourced from the southern sources representing the Meliata mélange. In this study, we use the geochemistry of detrital chromian spinels to identify the mafic and ultramafic source of the sediments and to compare them each other. Simultaneously, we compare their chemical compositions with those from the different Western Carpathian geological units, which could feed the Proč and Krynica basins during the Paleogene, where the Proč and Strihovce formations (fms), respectively, were deposited. Chromian spinels from the Proč and Strihovce fms exhibit similar geochemical characteristics (Cr# = 0.44–0.88 and 0.29–0.89, Mg# = 0.17–0.68 and 0.2–0.72, TiO2 = 0.0–3.67 and 0.01–2.08 wt.%, respectively). The spinels show both supra-subduction zone (SSZ) peridotite signatures and volcanic origin. Whereas volcanic spinels from the Proč Formation (Fm.) were formed under an ocean island basalt (OIB) and back-arc basin basalt (BABB) geodynamic setting, those from the Strihovce Fm. suggest a predominantly mid-ocean ridge basalt (MORB) origin. To avoid mistakes in the provenance interpretations, the data from garnet geochemistry of both formations is supplied. The analysed Cr-spinels do not absolutely overlap with spinels reported from the Meliata Unit, and their composition indicates at least two independent sources.

Klippen Belt, Flysch Belt and Inner Western Carpathian Paleogene Basin Relations in the Northern Slovakia by Magnetotelluric Imaging

The paper presents the interpretation of magnetotelluric measurements along the SW–NE profile near Stara Ľubovňa (Northern Slovakia). The profile passes through the Outer Carpathian Flysch Belt, Klippen Belt and ends in the Inner Western Carpathians Paleogene NW from Ružbachy horst structure. The interpretation of the older measurements from profile Mt4 was utilized and, moreover, the 3-D geoelectrical model of studied region was constructed. The magnetotelluric data interpretations verified the northern inclination of Flysch belt structures and their smaller thickness out of Klippen Belt in direction to the Carpathian electrical conductivity zone axis. We consider this as a consequence of the flower structure—more precisely the southern branch of the suture zone related to mentioned conductivity zone. Northerly from this zone the thickness of the Outer Carpathian Flysch Belt increases and the structures have inclination to the south, i.e. to the subduction zone. The contact of Flysch Belt with Klippen Belt has a fault character and it is subvertical, slightly inclined to the North. The southern boundary between Klippen Belt and Inner Western Carpathians has also fault character and is very steep. We detect the continuation of the Ružbachy horst to the NE in the basement of Inner Western Carpathian Paleogene. The structural discordance between this horst and Klippen Belt direction is a result of younger tectonic processes. According to our results the depth distribution of the pre-Tertiary basement below the Inner Western Carpathian units is non-uniform; the basement is broken to a number of partial blocks—horsts and grabens.

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.

Vertical crustal motions across Eastern Tibet revealed by topography-dependent seismic tomography

Using a topography-dependent tomographic scheme, the seismic velocity structure of the Eastern Tibetan Plateau, including the uplifted Longmenshan (LMS) orogenic belt, is accurately imaged in spite of the extreme topographic relief in the LMS region and thick sedimentary covers in the neighbouring Sichuan Basin. The obtained image shows a high-resolution upper crustal structure on a 500 km-long profile that is perpendicular to the LMS. The image clearly shows that the crystalline basement was uplifted within the LMS orogenic belt, and that the neighbouring Songpan-Ganzi Terrane was covered by a thick flysch belt, with evidence of near-surface thrust faults caused by convergence between Eastern Tibet and the Sichuan Basin. The indication that the lower crust beneath the LMS was folded and pushed upwards and the upper crust was removed by exhumation, supports the concept of a lower crustal channel flow beneath Eastern Tibet. The image also reveals that the destructive Wenchuan earthquake of year 2008 occurred in the upper crust, directly at the structural discontinuity between Eastern Tibet Plateau and the Sichuan Basin.

ICHNOFOSILIE MYSLEJOVICKÉHO SOUVRSTVÍ DRAHANSKÉHO KULMU (SPODNÍ KARBON, MORAVSKOSLEZSKÁ JEDNOTKA ČESKÉHO MASIVU)

The research in this study is focused on trace fossils of the Myslejovice Formation, which is one of the lithostratigraphical units in the Lower Carboniferous sequences of the Drahany Culm Basin that belongs to the large area of Rhenohercynian Zone of the Variscan orogenetic flysch belt. Ichnofossils have mainly been collected in the southeastern part, near Vyškov. The material comes from the collection of Mr. Veleslav Lang which is nowadays stored in the Regional Museum of Olomouc. From this collection total 615 specimens in 10 ichnogenera and 13 following ichnospecies were determined and redefi ned: ?Alcyonidiopsis isp., Cosmorhaphe isp., Dictyodora liebeana, Diplocraterion parallelum, Gordia isp., Chondrites cf. intricatus, Chondrites isp., Nereites missouriensis, Nereites isp., Phycosiphon incertum, Planolites beverleyensis, Planolites isp. and Rhizocorallium isp. The revised material comes from the following locations: Opatovice, Habrovany, Hamiltony, Ježkovice, Lhota, Luleč, Myslejovice, Nemojany – Blatická dolina, Nemojany, Otaslavice, Pístovice, Radslavice and Rychtářov. The overall character of ichnoassemblages indicates conditions of Nereites ichnofacies, which is typical for the distal parts of the suprafan turbidite lobes. Compared to other areas of Culm facies in Middle Europe, assemblages of the Myslejovice Formation belong among the less diversified.

Properties, durability and use of glauconitic Godula sandstones: a relatively less known building stone of the Czech Republic and Poland

Greenish glauconitic sandstones from the Middle Member of the Godula Formation of the Outer Western Carpathians flysch belt represent traditional building stone used in the north-eastern part of the Czech Republic and adjoining part of south Poland for about a thousand years. Despite the longstanding history of their utilisation in constructions and monuments, the amount of information about properties, durability and places of use is given in the existing literature only to a very limited extent. The Godula sandstones under study exhibit a high bulk density (up to 2610 kg/m3), relatively low water absorption capacity (0.7–3.0 wt%) and total porosity (1.7–9.4%), high values of P-wave velocity within psammitic rocks (3120–4290 m/s), and high to very high strength (uniaxial compressive strength 102.7–155.8 MPa, splitting tensile strength 4.0–10.0 MPa). However, in contrast to high quality of stone properties, the degree of their durability especially in the case of exterior use may often be very low, and stone deterioration can frequently advance very rapidly. Godula sandstones are characterised by a significant dominance of pores with diameter smaller than 1 μm. The character of pore space represents the principal and general reason of Godula sandstone deterioration susceptibility. Deterioration rate and specific weathering forms are subsequently strongly affected, in detail, by the heterogeneity of the mineralogical composition and anisotropy of rock texture within the individual sandstone bed. The data about composition, properties and stability of the Godula sandstones published in this paper could help architects or designers to understand the decay causes experienced by these types of sandstones and how to prevent them and may also serve as a guide for restoration and conservation works.

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.

Paleogene palaeogeography and basin evolution of the Western Carpathians, Northern Pannonian domain and adjoining areas

The data about the Paleogene basin evolution, palaeogeography, and geodynamics of the Western Carpathian and Northern Pannonian domains are summarized, re-evaluated, supplemented, and newly interpreted. The presented concept is illustrated by a series of palinspastic and palaeotopographic maps. The Paleogene development of external Carpathian zones reflects gradual subduction of several oceanic realms (Vahic, Iňačovce-Kričevo, Szolnok, Magura, and Silesian-Krosno) and growth of the orogenic accretionary wedge (Pieniny Klippen Belt, Iňačovce-Kričevo Unit, Szolnok Belt, and Outer Carpathian Flysch Belt). Evolution of the Central Western Carpathians is characterized by the Paleocene–Early Eocene opening of several wedge-top basins at the accretionary wedge tip, controlled by changing compressional, strike-slip, and extensional tectonic regimes. During the Lutetian, the diverging translations of the northward moving Eastern Alpine and north-east to eastward shifted Western Carpathian segment generated crustal stretching at the Alpine-Carpathian junction with foundation of relatively deep basins. These basins enabled a marine connection between the Magura oceanic realm and the Northern Pannonian domain, and later also with the Dinaridic foredeep. Afterwards, the Late Eocene compression brought about uplift and exhumation of the basement complexes at the Alpine-Carpathian junction. Simultaneously, the eastern margin of the stretched Central Western Carpathians underwent disintegration, followed by opening of a fore-arc basin – the Central Carpathian Paleogene Basin. In the Northern Hungarian Paleogene retro-arc basin, turbidites covered a carbonate platform in the same time. During the Early Oligocene, the rock uplift of the Alpine-Carpathian junction area continued and the Mesozoic sequences of the Danube Basin basement were removed, along with a large part of the Eocene Hungarian Paleogene Basin fill, while the retro-arc basin depocentres migrated toward the east. The Rupelian basins gained a character of semi-closed sea spreading from the Magura Basin across the Central Western Carpathians up to the Hungarian Paleogene Basin. In the Late Oligocene, the Magura Basin connection with the Northern Hungarian Paleogene Basin remained open, probably along the northern edge of the Tisza microplate, and anoxic facies were substituted by open marine environments.

Hydromorphological parameters of natural channel behavior in conditions of the Hercynian System and the flysch belt of the Western Carpathians on the territory of the Czech Republic

A fundamental prerequisite for assessing the current ecological status of streams is the establishment of reference conditions for each stream type that serve as a benchmark. The hydromorphological reference conditions reflect the natural channel behavior, which is extremely variable. Significant parameters of natural channel behavior were determined using a combination of four selected statistical methods: Principal Component Analysis, Agglomerative Hierarchical Clustering, correlation, and regression. Macroscale analyses of data about altitude, stream order, channel slope, valley floor slope, sinuosity, and characteristics of the hydrological regime were conducted for 3197 reaches of major rivers in the Czech Republic with total length of 15,636km. On the basis of selected significant parameters and their threshold values, channels were classified into groups of river characteristics based on shared behaviors. The channel behavior within these groups was validated using hydromorphological characteristics of natural channels determined during field research at reference sites. Classification of channels into groups confirmed the fundamental differences between channel behavior under conditions of the Hercynian System and the flysch belt of the Western Carpathians in the Czech Republic and determined a specific group in the flattened high areas of mountains in the Bohemian Massif. Validating confirmed the distinctions between groups of river characteristics and the uniqueness of each one; it also emphasized the benefits of using qualitative data and riparian zone characteristics for describing channel behavior. Channel slope, entrenchment ratio, bed structure, and d50 were determined as quantitative characteristics of natural channel behavior.

NOVÝ VÝSKYT MENILITOVÉHO SOUVRSTVÍ U DŘEVOHOSTIC

The Menilite Formation is an important lithostratigraphic member of the Krosno-menilite Unit in the Carpathian Flysch Belt. The rocks of the Menilite Formation occur as small bodies also within Sub-Silesian Unit on the geological map sheet 25-13 Přerov. In this paper, we present new occurrence of chert layers of the Menilite Formation at ground elevation 275 which is situated 1.2 km easternlyof the village Dřevohostice. The rock body is formed of layers of laminated gray-white to gray-brown menilite chert interlayered by thin interpositions of weathered gray-green non-calcareous claystones. The menilite cherts consist of brownish-yellow and gray opal laminae with limonite and chalcedony streaks. Opal laminae have thickness mostly in range of 1–10 mm. Rock matrix is cut by numerous veins formed by opal and chalcedony which originated during at least two diff erent events. Menilite cherts sporadicallyenclose small siliceous chalcedony geodes. Claystones have pelitic texture with a clotted inner structure and contain siliceous sponge spicules and other non-specified microfossils (probably planktonic diatoms). The cherty layers documented in a dug probe have WNW–ESE direction with inclination to SSW under the angle of 25°. The sediments were folded during the overthrust of the Sub-Silesian Nappe on the Carpathian Foredeep in the Karpatian and during subsequent late-tectonic rotations towards NW.

Connectivity of the coarsest fraction in headwater channels: imprints of fluvial processes and debris‐flow activity

Some steep headwater streams of the mid‐mountains landscape of the flysch belt of the estern arpathians are affected by debris flows. Connectivity of the largest boulder and cobble fractions has been evaluated in steep streams found in the transitional zones between the hillslopes and alluvial cones of similar lithology and watershed morphometry. Two longitudinal profiles affected by past debris‐flow activity and two longitudinal profiles void of such processes were selected. In the first case, active channels were characterised by the presence of the coarsest fraction, while a downstream trend of sediment coarsening or fining lacked any influence of contemporary fluvial processes and sediment supply. In addition, debris‐flow‐affected streams showed greater differences between the middle axis of the coarsest particle and the particle‐size index including the lengths of all three axes, which is most likely the result of limited active fluvial transport. All the studied streams demonstrated general downstream fining of the largest particles, which resulted from local flysch lithology containing more resistant sandstones in the upper parts of the watershed. The trend of sediment fining was more rapid in the longitudinal profiles unaffected by past debris flows. These types of streams also showed adjustment of the coarsest bed fraction to contemporary processes in channels by sediment coarsening in incised reaches and sediment fining in depositional reaches as well as by downstream response to some lateral sediment inputs. The index of the unit stream power showed no correlation with the considered coarsest fraction in both fluvial‐dominated channels and debris‐flow‐affected channels.

Assessing provenance of Upper Cretaceous siliciclastics using spectral γ-ray record

AbstractThe relationship between contents of clay minerals/grain size and spectral γ-ray record (concentrations of K, U and Th) in sediments is used for interpretation of sedimentary facies in wire-line logs. However, this approach is often complicated by the multi-component nature of mineralogically immature siliciclastics. As mineralogy of the source material and grain-size sorting during transport both contribute to the detrital composition of the final sediment, a joint study of facies and outcrop γ-ray spectra can potentially make the latter an effective tool in provenance studies. This paper provides comparison of outcrop γ-ray data and detailed facies mapping with mineral and chemical composition of the rocks (modal composition; transparent heavy mineral assemblages; WDX SEM chemistry of minerals) and interprets them in terms of provenance changes. We studied the Upper Cretaceous, synorogenic siliciclastic sediments of the Mazák and Godula Formations (Silesian Unit of the Western Carpathians flysch belt). Decreasing mineral maturity of the studied sandstones is consistent with provenance change from craton interior – (Mazák Formation) to transitional continental and recycled orogen sources (Godula Formation). Two major phases of K, U and Th concentration shifts, which occurred close to the Mazák/Godula Formation and Middle/Upper Godula Members boundaries, are consistent with changes in main detrital modes. These trends indicate gradually accelerated influx of material derived from high-grade metamorphic and plutonic rocks during deposition of the Mazák and Godula Formations. These changes are interpreted as reflecting a gradual exhumation and erosion of deeper crustal levels of the source area, the Silesian ridge.

Total water content thresholds for shallow landslides, Outer Western Carpathians

Shallow landslides are fairly frequent natural processes which emerge as a result of both rainfall and rapid snowmelt in the Flysch Belt of the Outer Western Carpathians. We estimated the total water content thresholds for the previously defined seven phases of increased landsliding which took place between 1939 and 2010 around the Napajedla meteorological station. The time series were reconstructed on the basis of data from surrounding stations. Rainfalls with the highest intensities (>1 mm/min) were removed from the set. Rainfall of such an intensity primarily causes overland flow and soil erosion and does not contribute to landslide threshold. The snow water equivalent was computed on the basis of the snow height, and possible errors were evaluated as interval estimations. An interval of 10 days before a landslide phase was selected for the total water content threshold. The resulting lower boundary (67.0 mm/10 days) and upper boundary (163.3 mm/10 days) thresholds of water infiltrated into soil during an event shall be part of the prepared online warning system in this area.

Genesis of Syntectonic Hydrothermal Veins in the Igneous Rock of Teschenite Association (Outer Western Carpathians, Czech Republic): Growth Mechanism and Origin of Fluids

Abstract Hydrothermal mineralization hosted by the Lower Cretaceous igneous rock of the teschenite association at Jasenice (Silesian Unit, Flysch Belt, Outer Western Carpathians) occurs in two morphological types - irregular vein filled by granular calcite and regular composite vein formed by both fibrous and granular calcite and minor chlorite, quartz, and pyrite. Crosscutting evidence indicates that the granular veins are younger than the composite vein. The composite vein was formed by two mechanisms at different times. The arrangement of solid inclusions in the marginal fibrous zone suggests an episodic growth by the crack-seal mechanism during syntectonic deformation which was at least partially driven by tectonic suction pump during some stages of the Alpine Orogeny. Both the central part of the composite vein and monomineral veins developed in a brittle regime. In these cases, the textures of vein suggest the flow of fluids along an open fracture. The parent fluids of both types of vein are characterized by low temperatures (Th=66-163 °C), low salinities (0.4 to 3.4 wt. % NaCl eq.), low content of strong REE-complexing ligands, and δ18O and δ13C ranges of + 0.2/+12.5 %. SMOW and -11.8/-14.1 %. PDB, respectively. The parent fluids are interpreted as the results of mixing of residual seawater and diagenetic waters produced by dewatering of clay minerals in the associ-ated flysch sediments. The flow of fluids was controlled by tectonic deformation of the host rock.

Minerały ciężkie w profilu utworów miocenu w otworze wiertniczym Kazimierza Wielka (Donosy) PIG-1 (północny skraj zapadliska przedkarpackiego)

HEAVY MINERALS IN THE MIOCENE DEPOSITS FROM THE KAZIMIERZA WIELKA (DONOSY) PIG-1 BOREHOLE (NORTHERN MARGIN OF THE CARPATHIAN FOREDEEP) Abstract. The paper presents the results of grain size and mineral content studies of six samples taken from Middle Miocene deposits (Machow Formation) in the Kazimierza Wielka (Donosy) PIG-1 borehole. The distinguished garnet association with zirconium, tourmaline, staurolite, and biotite suggests the Carpathian Flysch Belt as the most possible source area of the detrital minerals in the formation.

Magnetic fabric and petrology of Miocene sub-volcanic sills and dykes emplaced into the SW Flysch Belt of the West Carpathians (S Moravia, Czech Republic) and their volcanological and tectonic implications

Magnetic fabrics were investigated in the sub-volcanic bodies occurring within the SW Flysch Belt of the Western Carpathians. Magnetite or low-Ti titanomagnetite is the principal carrier of the anisotropy of magnetic susceptibility (AMS) in these rocks, though various Fe–Ti oxides were also identified in minor amounts. The magnetic fabric in almost all sills and dykes is conformable to the shapes of the bodies and no doubt originated through more or less free magma flow that requires relatively open voids to be injected, that likely originated in an extensive tectonic regime. In an ankaramite sill, where the rock creates typical hexagonal columns, the magnetic fabric is related rather to the column axes than to the overall shape of the sill. The magnetic fabric formation in this sill is controlled by the post-emplacement process of the creation of the columns. At some studied localities, signs of post-magmatic Middle Miocene tectonic deformation are observed in the field, the youngest known in the Flysch Belt. As the magnetic fabric is unrelated to those signs, we conclude that these young tectonic movements did not penetrate ductilely in the volume of the volcanic body. It seems that the strain was focused to thin zones along the faults, since it did not change the preferred orientation of magnetic minerals in the rock volume substantially.

VÝSLEDKY MIKROPALEONTOLOGICKÉ REVIZE ŠARATICKÝCH CF VRTŮ

Restudy of archive foraminifer slides from Šaratice boreholes and new field observations allowed revision of the geology in the margin of the Carpathian Flysch Belt southeast of Brno. In the marginal zone originally assigned to the Němčice Formation newly three different formations were distinguished: Pouzdřany Formation of the Pouzdřany Nappe, and Němčice and Menilite formations of the Ždánice Nappe. Planktonic foraminifers were applied in biostratigraphical assignment of samples. Benthic communities were statistically evaluated using cluster analysis. Each formation has distinct microfossil taphocoenosis and characteristic benthic foraminifer community. Microfossil communities with abundant sponge spicules and diatom valves preserved in opal and also presence of small mollusc fauna and fish otoliths indicate that marginal zone of Ždánice Nappe was deposited little bit shallower than the more internal zones. Also lithology reflects different palaeoenvironment. Clays of the Menilite Formation are macroscopically undistinguishable from Hustopeče-type clays of the overlying Ždánice-Hustopeče Formation. The Ždánice-type sandstones are practically missing. Grey pelocarbonate concretions are frequent in both Menilite and Ždánice-Hustopeče formations. The marker lithologies of the Menilite Formation – the menilite chert and Dynów-type marlstone (or their analogues) – were not observed yet. Results of the revision show that the marginal zone of the Carpathian Flysch Belt in Šaratice area comprises tectonic slices of mentioned formations, the number and order of whose change from borehole to borehole.

STUDIUM SPODNOBADENSKÝCH BAZÁLNÍCH KLASTIK V OBLASTI PODZEMNÍHO ZÁSOBNÍKU PLYNU LOBODICE

The depositional environment and the provenance of the Lower Badenian basal clastics in the area of Lobodice subsurface gas storage were described during the studies of these sediments.Drill cores of Lobodice wells were studied in the total length of 110 m for the purpose of depositional environment evaluation. The textures and structures were described on these cores and on this basis three lithofacies were recognized. The lithofacies A is represented by grey matrix supported, granule conglomerate, very poorly sorted. This lithofaces has been interpreted as the product of deposition of a coarse grained delta. The lithofacies B is formed by fine and medium sandstone with ripple cross lamination, very well sorted sandstone. This facies was interpreted as the result of a relatively low energy of traction current, probably deposited in marine environment. The lithofacies C is formed by greyish clay siltstone, locally with planar lamination and common bioturbation. The lithofacies C was interpreted as the product of deposition in the off shore condition (outer part of the shelf?).The results of pebble analysis and analysis of the chemistry of garnets and rutiles were used for the evaluation of the source areas of the Lower Badenian basal clastics.Pebble analysis shows that the studied Lower Badenian clastics are polymict. Grey limestones dominate in the pebble spectra and also oft en represent the largest clasts. Light-coloured limestones, shales and graywackes (most probably Culmian), quartzes and dolomites are relatively common. The content of pebbles of crystalline rocks is relative low. These results indicate the prevalence of sedimentary rocks in the source area and/or recycling of the source material. This results together with garnet and rutile analysis point to the source from the Culmian rock of Drahanská Vrchovina Upland and Nízký Jeseník Highland (especially the rocks of the Myslejovice Formation) and also probably from the Carpathian Flysch Belt.

Regional and local phenomena influencing the thermal state in the Flysch belt of the northeastern part of Slovakia

Abstract The locality of the northeastern most part of Slovakian Flysch belt belongs to interesting areas in terms of the interpretation of geothermal conditions in mutual relation with the lithosphere structure and their tectonic development. The evaluation of the geothermal energy sources parameters of this locality is likewise worthwhile. The region under study has the centre in position of the borehole Zboj ZB-1 and spreads out Slovakia also in Poland and Ukraine. Our contribution provides the analyses of existing geothermal data enhanced by the construction of temperature field models corresponding to the global and local aspects that influence the temperature and heat flow density distributions. The analyses are related to the structures and effects of separate phenomena along as well as across the Carpathian arc. The model calculations were carried out both by analytical and numerical methods of solving the heat transfer equations including their steady state forms and transient cases too. Besides the regional trend of thermal activity decrease in direction from East-Slovakian Basin to the outer Carpathian units the combined local influences are applied: subsurface thermophysical parameters of rock complexes distributions, non-stationary sources from supposed subvolcanic bodies in close surroundings of borehole Zboj ZB-1, and the effects of the hydrological factors. Considering the observed higher thermal activity in arched zone along the Carpathian structures we discussed the thermal effects of rock complexes supposed as a source of regional Carpathian Conductivity Anomaly and the transfer of heat from East-Slovakian Basin to Outer Carpathian Flysch units. The analysis and the modelling results suggest that the mentioned activity is caused by the influences of source type phenomena mainly related to deep fault systems at the margin of the European Platform. That means the anomalies in heat flow density distribution can reach the value 70 mW/m2 and more in the zone above the thermally active deep-fault system with the presence of volcanism and hydrothermal activities.

Cosmogenic nuclide burial age of the Sanying Formation and its implications

The Pliocene fluvial/lacustrine sediments of the Sanying Formation lie along the Red River fault and its northwest extension; their majority outcrops appear around Eryuan. The Sanying Formation is characterized by multiple intercalated coal layers and its unconformities contact with the underlying Triassic limestone and the overlying Quaternary coarse sediments. Cosmogenic nuclide burial dating confirms the Pliocene age of the Sanying Formation. The burial ages of the overlying Quaternary sediments provide the lower age limit of the Sanying Formation: 2 Ma. Detrital zircon U-Pb age distribution suggests provenance of the Sanying Formation traced to the Songpan-Ganzi flysch belt. From the spatial distribution as well as sedimentary and fault ages, we found a strong connection of the Sanying Formation with the Red River and the Jianchuan faults. We therefore propose that activation of the Red River and the Jianchuan faults during the Late Miocene resulted in subsidence of basins in the extensional areas around Eryuan and in the middle to south segments of the Red River fault. The basins were filled with water carried by the Jinsha River and overflow-lakes formed within the basins where the Sanying Formation was deposited. Most of the lakes were dried and sedimentation of the Sanying Formation ceased due to the uplift of the Yunling Mountains, which forced rerouting of the Jinsha River at the beginning of Quaternary.