Polish Carpathian Foredeep Basin Research Articles

The evolution of the Carpathian Foredeep Basin during the latest Badenian and Sarmatian (Middle Miocene): inferences from micropalaeontological data

Seven Middle Miocene (Upper Badenian to Lower Sarmatian) sedimentary sections of the Central Paratethys, two from the Polish Carpathian Foredeep Basin (PCFB) and five from the Eastern Carpathian Foreland Basin (ECFB) of Romania and the Republic of Moldova have been analysed micropalaeontologically to better constrain the Badenian-Sarmatian Extinction Event, characterized by significant taxonomic impoverishment of both foraminifers and ostracods. Our studies show significant palaeoenvironmental changes in the basin including depth, salinity, oxygenation, and organic matter flux. The occurrence of moderately diverse planktonic foraminifera (Globigerina, Globigerinita, Globorotalia, Trilobatus, Orbulina, Velapertina) in the Upper Badenian deposits of the PCFB as well as in the ECFB and their rarity in the lowermost Sarmatian indicate an almost fully marine environment during the latest Badenian, followed by a significant regression and possible appearance of much more restricted marine conditions across the boundary. The taxonomic composition of the Sarmatian foraminifera, ostracoda and calcareous nannofossils indicate that during this interval the salinity fluctuated strongly, with the water regime varying from brackish to normal marine. In addition, the identified micropalaeontological assemblages identified show palaeoenvironmental similarity across different basins of the Central Paratethys. This supports a hypothesis of possible connections during the latest Badenian between different areas of the Central Paratethys, as well as of the existence of a gateway between the Central Paratethys and the Mediterranean realm

Experimental insights into consolidation rates during one-dimensional loading with special reference to excess pore water pressure

Consolidation rate has significant influence on the settlement of structures founded on soft fine-grained soil. This paper presents the results of a series of small-scale and large-scale Rowe cell consolidation tests with pore water pressure measurements to investigate the factors affecting the consolidation process. Permeability and creep/resistance structure factors were considered as the governing factors. Intact and reconstituted marine clay from the Polish Carpathian Foredeep basin as well as clay–sand mixtures was examined in the present study. The fundamental relationship correlating consolidation degrees based on compression and pore water pressure was assessed to indicate the nonlinear soil behaviour. It was observed that the instantaneous consolidation parameters vary as the process progresses. The instantaneous coefficient of consolidation first drastically increases or decreases with increase in the degree of consolidation and stabilises in the middle stage of the consolidation; it then decreases significantly due to viscoplastic effects occurring in the soil structure. Based on the characteristics of the relationship between coefficient of consolidation and degree of dissipation at the base, the consolidation range that complies with theoretical assumptions was established. Furthermore, the influence of coarser fraction in clay–sand mixtures in controlling the consolidation rates is discussed.

Radio-isotopic age and biostratigraphic position of a lower Badenian tuffite from the western Polish Carpathian Foredeep Basin (Cieszyn area)

The early Badenian interval in the Central Paratethys realm is characterized by a major marine transgression into the Pannonian and Carpathian Foredeep basins. In the western part of the Polish Carpathian Foredeep, Badenian sedimentation started generally with conglomerates (Debowiec Formation) passing into a thick succession of claystones and mudstones with rare sandstone interbeds (Skawina Formation). Profiles containing a full sequence of lower Badenian strata are relatively rare, and are mainly known from boreholes. In this paper, we present new results on samples taken from such a borehole (Kaczyce K2/07) located near the town of Cieszyn. We focus on reconstructing the chronology of the lower Badenian marine sediments at the beginning of the transgression in the Carpathian Foredeep (lower Skawina Fm.) using radio-isotopic dating ( 40 Ar/ 39 Ar) of a volcanoclastic layer (tuff and tuffite) and biostratigraphy of calcareous nannoplankton and foraminifera.The weighted mean 40 Ar/ 39 Ar age for sanidine separates from the tuff provided an age of 14.27 ± 0.03 Ma. This age is consistent with the NN5 and MNN5a nannofossil zones determined in this study. Our foraminiferal assemblages show that the basal beds of the Skawina Formation up to the tuffites correspond to the Orbulina suturalis–Praeorbulina glomerosa Zone (according to Cicha et al., 1975) and cover the interval of the Lower Lagenidae Zone–lowermost Upper Lagenidae Zone (Grill, 1941). The petrographic data from the tuffite allow correlation of the tuffite from the Kaczyce K2/07 borehole to the level of the Chelmek Tuffite Bed (Alexandrowicz, 1997) providing a regional correlation horizon for future studies.

A deep palaeovalley in the floor of Polish Carpathian Foredeep Basin near Pilzno and its control on Badenian (Middle Miocene) evaporite facies

The Pogorska Wola palaeovalley of combined tectonic and erosional origin dissects the Mesozoic floor of the Carpathian Foredeep Basin to a depth exceeding 1200 m. It formed during Paleogene times presumably due to fluvial and submarine erosion, concentrated along a local pre-Late Badenian graben system. All members of the foredeep’s Badenian-Sarmatian sedimentary fill attain distinctly greater values inside the palaeovalley than on top of elevated plateaux on palaeovalley shoulders. The fill comprises the Early to Late Badenian sub-evaporite Skawina Formation, the laterally equivalent Late Badenian evaporite Krzyzanowice and Wieliczka formations and the supra-evaporite Late Badenian to Early Sarmatian Machow Formation. Over the plateaux and in the highest palaeovalley segment, the evaporites are developed in the sulphate facies Krzyzanowice Formation, whereas in the lower palaeovalley segments chloride-sulphate facies evaporites of the Wieliczka Formation occur. The rock salt-bearing rocks are involved in thrusting and folding at the Carpathian orogenic front, which helps to assess the lateral extent of the Wieliczka Formation in seismic records. The deep palaeotopographic position of the evaporites inside the palaeovalley, combined with their lithological and sedimentary features, point to their formation via subaqueous gravity flow-driven redeposition of originally shallow-water evaporites, preferentially halite-bearing, presumably combined with precipitation from sulphate and chloride brines at the palaeovalley floor. Both the redeposited sediments and the brines must have come from the adjacent plateaux and from a thrust-sheet top basin, approaching from the south on top of the Cretaceous-Paleogene Carpathian flysch thrust wedge

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 Machow 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 , C yclicargolithus 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 Miechow 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.

Strontium isotope composition of Middle Miocene primary gypsum (Badenian of the Polish Carpathian Foredeep Basin): evidence for continual non‐marine inflow of radiogenic strontium into evaporite basin

AbstractStrontium isotope compositions of ancient sulphate deposits not only provide chemostratigraphic information but also offer insight into the system in which the evaporites precipitated. Primary gypsum from two Middle Miocene (Badenian) sections in southern Poland shows steadily higher 87Sr/86Sr ratios than those expected from a marine‐derived formation. The ratios are interpreted as the result of increasing inflow into the basin at the time of gypsum precipitation. Palaeogeographic reconstructions suggest that riverine runoff sources were situated in the West and East European platforms (to the north and east, respectively) and the Carpathians (to the south), which are mostly composed of Mesozoic sedimentary rocks; their dissolution cannot be responsible for the higher 87Sr/86Sr ratios recorded. We conclude that Archaean and Palaeoproterozoic igneous and supracrustal rocks of the Ukrainian Shield were the source of the higher 87Sr/86Sr ratios recorded in the Badenian primary gypsum. A distinctive decreasing trend of 87Sr/86Sr ratios from western Ukraine to southern Poland is explained by a consistent direction of brine inflow during gypsum crystallization (typical cyclonic circulation controlled by the Coriolis effect).

Sarmatian paleoecological environment of the Machów Formation based on the quantitative nannofossil analysis — a case study from the Sokołów area (Polish Carpathian Foredeep)

Sarmatian paleoecological environment of the Machów Formation based on the quantitative nannofossil analysis — a case study from the Sokołów area (Polish Carpathian Foredeep)The Machów Formation belongs to a supra-evaporitic succession of the Polish Carpathian Foredeep Basin (PCFB). Our studies were concentrated in the eastern part of the PCFB, north of Rzeszów. 33 samples were collected from five boreholes, at depth intervals as follows: Stobierna 2 — 1016-1338 m; Stobierna 3 — 715-1669 m; Stobierna 4 — 1016-1238 m; Stadnicka Brzóza 1 — 350-356 m and 1043-1667 m; Pogwizdów 2 — 1161-1390 m. The obtained biostratigraphical data gave evidence for the upper part of the NN6 (the Early Sarmatian) and for the NN7 (the lowermost part of the Late Sarmatian) Zones. All the nannofossil assemblages from Stobierna 2, Stobierna 4 and Pogwizdów 2 were assigned to the NN6 Zone. In the Stobierna 3 borehole the interval 1669-1113 m was assigned to NN6, whereas assemblages from depth interval 843-715 m belong to NN7 Zone. In Stadnicka Brzóza 1 interval 1667-1043 m belongs to NN6 Zone and interval 350-356 m to NN7 Zone. TheDiscoaster exilisZone (NN6) was defined by the presence ofReticulofenestra pseudoumbilica,Sphenolithus abies,Helicosphaera walbersdorfensisand absence ofDiscoaster kugleri.TheDiscoaster kugleriZone (NN7) assignment was based on the abundance ofCoccolithus miopelagicus(> 10 μm), used as an alternative species essentially confined to that interval, and absence ofCatinaster coalithus.The observed nannoplankton assemblages are predominantly composed of a high number of redeposited material, abundant long-ranging taxa and taxa resistant to carbonate dissolution. General assemblage compositions, obtained from quantitative data, indicate shallow near-shore environment and could confirm basin isolation.

Foraminiferal record of the Middle Miocene climate transition prior to the Badenian salinity crisis in the Polish Carpathian Foredeep Basin (Central Paratethys)

Foraminifers occurring in marls underlying the Middle Miocene Badenian gypsum in the northern Polish Carpathian Foredeep in one borehole section [Młyny (Busko) PIG 1] and in two dewatering pits in operating quarries (Leszcze and Borków) contain well-preserved foraminifers. Sixty-seven species of benthic and twenty-one species of planktonic foraminifers are recorded in the 12-m-thick section of the Młyny borehole. Benthic assemblages are characterized by the dominance of Bulimina and Uvigerina while planktonic assemblages are composed mainly by warm-water orbulinids and Globigerinoides spp. in the lower part of the Młyny section and by temperate-cold water Globigerina spp. in the upper part of the Młyny section as well as the Leszcze and Borków sections. The taxonomic composition of foraminiferal assemblages makes it possible to distinguish two foraminiferal zones in the Młyny borehole: the Orbulina suturalis and Uvigerina costai zones, and only the latter zone is accessible at Leszcze and Borków. The benthic foraminiferal successions in the studied interval suggest oxygenation and productivity changes in the Carpathian Foredeep Basin prior to the Badenian salinity crisis. Four intervals of lowered oxygenation and/or elevated organic flux to the sea-floor are recognized; the intervals in which foraminiferal assemblages suggest marine environments with lowered oxygenation in bottom waters alternate between the intervals where stress markers form less than 50% of the benthic foraminiferal assemblages. Benthic assemblages are moderately to highly diversified, and species have more equal frequencies. The upsection decrease in the proportion of planktonic foraminifers reflects the shallowing of the basin accompanied by a decrease in the temperature gradient between the upper (warmer) and deeper (colder) water beds. The average palaeotemperature of water based on d18O of Uvigerina and Globigerina decreased by ca. 2 and ca. 6°C, respectively (from 9.9 and 17.4°C in the Orbulina suturalis Zone to 7.9 and 11.5°C in the Uvigerina costai Zone, respectively). Below the gypsum, the d18O values of both benthic and planktonic foraminifers show quite large variations possibly due to the salinity increase. Coeval domination of benthic foraminiferal assemblages by Bulimina suggests increased surface water productivity and an increased organic flux to the sea-floor prior to the onset of evaporite deposition and/or salinity increase. &nbsp

Stages of development in the Polish Carpathian Foredeep basin

AbstractIn 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.

Palaeoenvironmental changes preceding the Middle Miocene Badenian salinity crisis in the northern Polish Carpathian Foredeep Basin (Borków quarry) inferred from foraminifers and dinoflagellate cysts

Study of foraminiferal and dinoflagellate cyst assemblages and palynofacies occurring in 2 m-thick marls cropping out beneath a giant gypsum intergrowth unit in the Borkow gypsum quarry in Southern Poland, one of the key Badenian evaporite sections in the Polish Carpathian Foredeep Basin, has shown the presence of 49 species of benthic foraminifers and 11 species of planktonic ones, and 51 dinoflagellate (including 8 redeposited ones). The composition of the foraminiferal fauna and its isotopic signal indicate temperature-stratified, nutrient-rich and thus less-oxygenated marine water. Changes in the relative abundance of epifaunal and infaunal species indicate a clear environmental change during the deposition of the marls. A middle to outer shelf marine, well-ventilated environment with moderate primary productivity existed during the deposition of the bottom part of the marls. Subsequently, infaunal bottom-dwellers became dominant due to a massive increase in food supply to the sea bottom and shallowing of the sea to inner - middle shelf depths, and than a decreasing trend of a relative abundance of the infaunal morphogroups is observed until the top of the marls that were deposited in an inner shelf environment with moderate primary productivity. The calculated palaeotemperatures for particular foraminifer taxa (Globigerina spp., Cibicidoides and Bulimina elongata) show a slight upsection decrease and a decrease in the temperature differences between the bottom and intermediate water beds. Palynofacies are composed of elements of mixed origin, including terrestrial, marine (mainly dinoflagellate cysts) and elements of uncertain derivation (structureless organic matter). The palynological content of most samples indicates their deposition in an open-marine marine environment, in the stable marine conditions of an open shelf basin with no salinity fluctuations. The sample just below the gypsum contains no dinoflagellate cysts, perhaps due to a drastic change in the photic zone leading to a complete collapse of the dinoflagellate flora. Very rare occurrence of planktonic foraminifers in that sample suggest the shallowing of the basin accompanied by a decrease in the temperature gradient between the upper (warmer) and lower (colder) water beds. A shallow, cold water marine environment is indicated for the topmost foraminiferal assemblage.

Neogene stress field in the central and eastern parts of the outer Polish Carpathian Foredeep

The Polish Carpathian Foredeep (PCF) is a foreland basin formed during the regional flexure of the East European continental lithosphere related to a continental collision in the Carpathian realm. The infill of the PCF basin consist of the uppermost Lower to the Upper Miocene (Ottnangian-Pannonian) sediments. These are mostly mudstones and clays, more rarely sandstones, limestones and evaporites. Numerous thrusts, strike-slip and normal faults, and even folds exist in the whole PCF. The orientation of these structures is variable but they show the privileged directions. The spatial analysis of structures and their crosscutting relationships, together with published seismic data permit conclude that the regional stress field in studied part of PCF was stable during the whole Neogene time till now. The orientation of the maximum horizontal stress axis was NNE-SSW. The local changes of the stress field orientation were caused by activity of the strike-slip fault in the foredeep basement or even the rotation of the basement blocks. The visible response on the basement activity were mostly outcrop-scale structures, namely the number and variety of structures are increasing in individual outcrop. However, the map-scale structures were also generated, for example so called Ryszkowa Wola Horst, a large pop-up structure.

Contrasting tectonic and sedimentary history of the central and eastern parts of the Polish Carpathian foredeep basin — results of seismic data interpretation

Polish Carpathian foredeep basin (PCFB) is located at the junction between Western and Eastern European Platforms. Such location caused different evolution of various parts of this basin. In the central part of the PCFB growth fault-propagation folds related to latest (Badenian) stages of thrusting in this segment of the Carpathians developed. Only minor normal faulting related to Miocene reactivation of older basement faults was detected. Paleovalleys mapped within the Mesozoic basement were interpreted as Palaeogene tectonically controlled erosional features developed after inversion of the Polish Trough. In the central PCFB post-evaporitic sediments were supplied into the foredeep basin from south, from the eroded Carpathians. In the eastern part of the PCFB, a system of large normal faults related to Miocene flexure-induced reactivation of inherited Mesozoic faults was identified. Within the hangingwall of this system, reverse faults, rotated blocks and basement pop-up structures were described. Their formation was related to combined effect of compressional stresses transferred from the Carpathian collision zone and reactivation of older large-scale fault caused by both flexural extension and strike-slip movements. During deposition of the Miocene foredeep sediments differential compaction also played an important role. Gentle onlap of the Middle Badenian evaporites by post-evaporitic sediments towards the NW was interpreted as a result of tectonically driven relative sea-level rise and re-establishment of marine connections with eastern Paratethys.

ABSTRACT: Compression Versus Extension in the Eastern Polish Carpathian Foredeep Basin (Miocene) and Its Bearing on Hydrocarbon System

ABSTRACT: Compression Versus Extension in the Eastern Polish Carpathian Foredeep Basin (Miocene) and Its Bearing on Hydrocarbon System

Miocene Tectonic Development of the Polish Carpathian Foredeep Basin  :ABSTRACT

Miocene Tectonic Development of the Polish Carpathian Foredeep Basin  :ABSTRACT