Stages of development in the Polish Carpathian Foredeep basin

In southern Poland, Miocene deposits have been recognised both in the Outer Carpathians and the Carpathian Foredeep (PCF). In the Outer Carpathians, the Early Miocene deposits represent the youngest part of the flysch sequence, while in the Polish Carpathian Foredeep they are developed on the basement platform. The inner foredeep (beneath the Carpathians) is composed of Early to Middle Miocene deposits, while the outer foredeep is filled up with the Middle Miocene (Badenian and Sarmatian) strata, up to 3,000mthick. The Early Miocene strata are mainly terrestrial in origin, whereas the Badenian and Sarmatian strata are marine. The Carpathian Foredeep developed as a peripheral foreland basin related to the moving Carpathian front. The main episodes of intensive subsidence in the PCF correspond to the period of progressive emplacement of the Western Carpathians onto the foreland plate. The important driving force of tectonic subsidence was the emplacement of the nappe load related to subduction roll-back. During that time the loading effect of the thickening of the Carpathian accretionary wedge on the foreland plate increased and was followed by progressive acceleration of total subsidence. The mean rate of the Carpathian overthrusting, and north to north-east migration of the axes of depocentres reached 12 mm/yr at that time. During the Late Badenian-Sarmatian, the rate of advance of the Carpathian accretionary wedge was lower than that of pinch-out migration and, as a result, the basin widened. The Miocene convergence of the Carpathian wedge resulted in the migration of depocentres and onlap of successively younger deposits onto the foreland plate

Geological structure and evolution of the Pieniny Klippen Belt to the east of the Dunajec River : a new approach (Western Outer Carpathians, Poland)

The area studied, known as the Małe (Little) Pieniny Mts., belongs to the Pieniny Klippen Belt (PKB), a suture zone that separates the Central Carpathians from the Outer Carpathian accretionary wedge. Along its northern boundary the PKB is separated from the Paleogene to Early Miocene flysch deposits of the Magura Nappe by a narrow, strongly deformed belt belonging to the Grajcarek tectonic Unit. This unit is composed of Jurassic, Cretaceous and Paleocene pelagic and flysch deposits. The Klippen units of the PKB are represented by Jurassic–Lower Cretaceous carbonate deposits overlain by Upper Cretaceous variegated marls and flysch deposits. We describe geological and biostratigraphic evidence concerning the palaeogeographic, stratigraphic and structural relationships between the Pieniny Klippen Belt and the Magura Nappe, that significantly modify previously held views on the evolution of the Małe Pieniny Mts. and the Polish sector of the PKB

Late Jurassic-Miocene evolution of the Outer Carpathian fold-and-thrust belt and its foredeep basin (Western Carpathians, Poland)

The Outer Carpathian Basin domain developed in its initial stage as a Jurassic-Early Cretaceous rifted passive margin that faced the eastern parts of the oceanic Alpine Tethys. Following closure of this oceanic basin during the Late Cretaceous and collision of the Inner Western Carpathian orogenic wedge with the Outer Carpathian passive margin at the Cretaceous-Paleocene transition, the Outer Carpathian Basin domain was transformed into a foreland basin that was progressively scooped out by nappes and thrust sheets. In the pre- and syn-orogenic evolution of the Outer Carpathian basins the following prominent periods can be distinguished: (1) Middle Jurassic-Early Cretaceous syn-rift opening of basins followed by Early Cretaceous post-rift thermal subsidence, (2) latest Cretaceous-Paleocene syn-collisional inversion, (3) Late Paleocene to Middle Eocene flexural subsidence and (4) Late Eocene-Early Miocene synorogenic closure of the basins. In the Outer Carpathian domain driving forces of tectonic subsidence were syn-rift and thermal post-rift processes, as well as tectonic loads related to the emplacement of nappes and slab-pull. Similar to other orogenic belts, folding of the Outer Carpathians commenced in their internal parts and progressed in time towards the continental foreland. This process was initiated at the end of the Paleocene at the Pieniny Klippen Belt/Magura Basin boundary and was completed during early Burdigalian in the northern part of the Krosno Flysch Basin. During Early and Middle Miocene times the Polish Carpathian Foredeep developed as a peripheral foreland basin in front of the advancing Carpathian orogenic wedge. Subsidence of this basin was controlled both by tectonic and sedimentary loads. The Miocene convergence of the Carpathian wedge with the foreland resulted in outward migration of the foredeep depocenters and onlap of successively younger deposits onto the foreland

The position and age of the youngest deposits in the Mszana Dolna and Szczawa tectonic windows (Magura Nappe, Western Carpathians, Poland)

The Mszana Dolna and Szczawa tectonic windows are composed of deposits belonging to the Fore-Magura Group of units. The central and most uplifted part of these windows are dominated by relatively flat laying deposits belonging to the Krosno Formation (Oligocene) of the Dukla Unit. The western, eastern and southern marginal parts of the Mszana Dolna tectonic window are occupied by strongly tectonized, Cretaceous-Oligocene deposits assigned to the Grybów Unit. The Szczawa tectonic window is entirely built up of Oligocene deposits of the Grybów Unit. The youngest deposits of the Mszana Dolna tectonic window are correlated with zone NP24 (Dukla Unit) and NP23-NP25 (Gryb6w Unit). In the Szczawa tectonic window (Grybow Unit), the NP22-NP24 Zone was determined in the Grybow Beds, whereas the Cergowa Beds belong to zone NP24. Such age determination corresponds well with that of the southern part of the Silesian and Dukla units. The deposits of the Dukla and Grybow units are tectonically covered by the Cretaceous-Eocene deposits of the Magura Nappe. During the latest Oligocene a thrusting of the Magura Nappe onto the Fore-Magura sedimentary basin began (Grybów and Dukla). This process was probably initiated under the submarine condition. The last of the over thrusting stages took place probably during the Middle Miocene, and resulted in the development of the Mszana-Dolna duplex structure

Newly discovered Early Miocene deposits in the Nowy Sącz area (Magura Nappe, Polish Outer Carpathians)

In the Nowy Sącz area Early Miocene marine deposits have been discovered in the southern part of the Rača Subunit, and at the front ofthe Bystrica Subunit of the Magura Nappe. These deposits belong to the Zawada Formation, which is represented by medium- to thick-bedded glauconitic sandstones with intercalations of thick-bedded marls and marly claystones. The formation is at least 550 mthick. Calcareous nannofossils show the age of the formation to be Early Burdigalian (NN1-2-3 biozones). Due to a lack of exposuresthe relationship between the deposits of the Malcov and the Zawada formations is not yet clear. However, comparing the youngest age of the Malcov Formation in the Nowy Sącz I borehole (NP 25) with the age of the Zawada Formation suggests sedimentary continuity transition between these formations

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

Quantitative studies of the calcareous nannoplankton of Sarmatian deposits : case studies in the Sieniawa-Rudka area (Outer Carpathian Foredeep, Poland)

The aim of this study was the qualitative and quantitative analysis of the calcareous nannofossil assemblages of the Machów Formation, belonging to the supra-evaporitic complex of the Polish Carpathian Foredeep Basin (PCFB). The work was concentrated in the eastern part of the PCFB, in the Sieniawa–Rudka area (Ryszkowa Wola Horst). Samples were collected from the Rudka-13 and Wylewa-1 boreholes. On the basis of calcareous nannoplankton, these deposits were assigned to the upper part of the NN6 Zone combined with the NN7 Zone, which corresponds to the Sarmatian s.s. of the Central Paratethys (upper Serravallian of the Mediterranean scale). Conclusive determination of the biozone NN7 was problematic, owing to the absence of the rare zonal marker species Discoaster kugleri. The typical association of the undivided NN6–NN7 Zone was of low species diversity and usually dominated by Coccolithus pelagicus, Cyclicargolithus floridanus and Reticulofenestra pseudoumbilica (> 7 µm). On the basis of the relative abundance of species, a significant amount of redeposition was deduced. The reworked nannofossils were mostly Eocene in age. The Oligocene, Early Miocene and Late Cretaceous species occurred much less frequently. The dominance of Eocene forms indicates the Carpathians as the main supply area. The Late Cretaceous taxa may have originated from the Senonian marly deposits of the Miechów Trough in the north. Statistical treatment of the quantitative data was performed using multivariate cluster analysis and Nonmetrical Multidimensional Scaling (nMDS). The composition of the calcareous nannofossil assemblages, together with the high percentage of allochthonous taxa, indicate a shallow, coastal environment with a high supply of nutrients

New data on the late Badenian-Sarmatian depositsof the Nowy Sącz Basin (Magura Nappe, Polish Outer Carpathians) and their palaeogeographical implications

In the Nowy Sącz Basin, newly exposed Middle Miocene deposits have been studied and sam pled in the Kamienica Nawojowska, Poprad and Dunajec rivers. The calcareous nannoplankton of the fresh water to marine deposits was examined. Pale grey and brown clayey shales with plant remains and thin seams of lignite represent the freshwater deposits of the Biegonice Formation. These deposits pass upwards into ca. 50 m thick packet of brackish and marine deposits, represented mainly by dark marly shales with bivalves and gastropods of the Iwkowa and Niskowa formations. These deposits contain relatively rich late Badenian to Sarmatian calcareous nannoplakton (NN6/7Zone)