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    Wyświetlanie 1-8 z 8
    Tytuł:
    Barnasiówka Radiolarian Shale Formation - a new lithostratigraphic unit in the Upper Cenomanian-lowermost Turonian of the Polish Outer Carpathians (Silesian Series)
    Formacja Łupków Radiolariowych z Barnasiówki - nowa jednostka litostratygraficzna w górnym cenomanie i najniższym turonie w Polskich Karpatach Zewnętrznych (Seria Śląska)
    Autorzy:
    Bąk, K.
    Bąk, M.
    Paul, Z.
    Powiązania:
    https://bibliotekanauki.pl/articles/191433.pdf
    Data publikacji:
    2001
    Wydawca:
    Polskie Towarzystwo Geologiczne
    Tematy:
    lithostratigraphy
    biostratigraphy
    Cenomanian
    Turonian
    Silesian Nappe
    Outer Carpathians
    Opis:
    A new lithostratigraphic unit - the Barnasiówka Radiolarian Shale Formation - is herein defined. It belongs to the Silesian Series of the Outer Carpathians. The formation consists of biosiliceous deposits rich in organic matter, laid down around the Cenomanian-Turonian boundary. The formation includes, from bottom to top: (1) a series of green to black, calcareous and siliceous shales, alternating with layers of chert, siliceous siltstone and sandstone (up to 10 m thick); (2) a series of green to black, argillaceous to siliceous shales, intercalated with tuffites, bentonites, and a ferromanganese layer (up to 9 cm thick) in its middle part (up to 3.2 m thick); (3) a series of green and red, siliceous siltstones and cherts with intercalations of non-calcareous green shales and benthonites (up to 2 m thick). The total thickness of the formation ranges from 0.5 m in the eastern part (reduced tectonically?) up to about 14-15 m in the middle and the western parts of the Silesian Nappe, due to the increase in the number and thickness of turbidite intercalations. The formation represents the Holocryptocanium barbui - Holocryptocanium tuberculatum through the Alie-vium superbum radiolarian zones and the Uvigerinammina praejankoi-Uvigerinammina jankoi foraminiferal zones, which correspond to the Upper Cenomanian through the lowermost Turonian. Microfacies and geochemical characteristics of the distinguished lithological types are presented in this paper, based on recent studies and published data. The described formation has been compared and correlated with deposits of similar age from other tectonic- facies units of the Outer Carpathians in Poland and Ukraine.
    Źródło:
    Annales Societatis Geologorum Poloniae; 2001, 71, No 2; 75-103
    0208-9068
    Pojawia się w:
    Annales Societatis Geologorum Poloniae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Successive stages of calcitization and silicification of Cenomanian spicule-bearing turbidites based on microfacies analysis, Polish Outer Carpathians
    Autorzy:
    Bąk, B.
    Górny, Z.
    Bąk, K.
    Wolska, A.
    Stożek, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/191355.pdf
    Data publikacji:
    2015
    Wydawca:
    Polskie Towarzystwo Geologiczne
    Tematy:
    calcitization
    silicification
    sponge spicules
    spicule-bearing turbidites
    cherts
    Cenomanian
    Outer Carpathians
    Opis:
    Mid-Cretaceous turbidites with large proportions of sponge spicules are widely distributed in the Silesian Nappe of the Outer Carpathians, giving rise to diversified types of sediments, from spiculites to spicule-bearing siliciclastics and calcarenites. Part of this succession, Middle–Late Cenomanian in age, was transformed into cherts. A microfacies study showed that these turbidite sediments underwent several stages of calcitization and silicification, which took place during Mid-Cretaceous times in different sedimentary environments, i.e., on a northern shelf bordering the Silesian Basin and on a deep sea floor. The first diagenetic changes were related to changes to the biotic components of the turbidite layers, dominated by siliceous sponge spicules. This process, which took place in the spiculitic carbonate mud on the shelves, was related to the calcitization of sponge spicules. Calcareous clasts and calcified skeletal elements also were corroded by bacteria. After transportation down the slope, the biogenic and siliciclastic particles were deposited below the carbonate compensation depth. Taphonomic processes on the basin floor and alternating phases of carbonate and silica cementations, recrystallization and dissolution occurred in these sediments and were related to the diversification in composition of successive turbidite layers. Silicification was related to the formation of quartz precipitates as fibrous chalcedony or microcrystalline quartz, which were derived from the earlier dissolution of amorphous silica, originating mostly from siliceous sponge spicules and radiolarian skeletons. However, a source of silica from hydrothermal vents was also possible. The initial silica precipitation could have taken place in a slightly acidic environment, where calcite was simultaneously dissolved. A number of silicification stages, visible as different forms of silica precipitate inside moulds after bioclasts, occur in the particular turbidite layers. They were related to changes in various elements of the pore-water profile after descending turbidity-current flows. A very low sedimentation rate during the Middle–Late Cenomanian in the Silesian Basin may have favoured the sequence of initial calcitization and silicification stages of the turbidite sediments.
    Źródło:
    Annales Societatis Geologorum Poloniae; 2015, 85, 1; 187-203
    0208-9068
    Pojawia się w:
    Annales Societatis Geologorum Poloniae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Environmental changes during the Cenomanian-Turonian Boundary Event in the Outer Carpathian basins: a synthesis of data from various tectonic-facies units
    Zmiany w środowisku basenów Karpat zewnętrznych w czasie globalnego zdarzenia oceanicznego na granicy cenomanu i turonu; synteza wyników badań z różnych jednostek tektoniczno-facjalnych
    Autorzy:
    Bąk, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/191660.pdf
    Data publikacji:
    2007
    Wydawca:
    Polskie Towarzystwo Geologiczne
    Tematy:
    Cenomanian-Turonian boundary event
    stratigraphy
    palaeoenvironment
    Late Cretaceous
    Outer Carpathians
    Polska
    Opis:
    The paper summarizes the results of author’s studies on the environmental changes around the Cenomanian-Turonian Boundary Event (CTBE) in the Outer Carpathian basins located close to the northern margin of the Western Tethys, whose sea floor was situated below the calcite compensation depth. The sedimen- tary, biotic and chemical records allowed to recognize the successions related to the oceanic anoxic event (OAE-2) and trace changes around this event sediments within the frame of the stable carbon isotope excursion and biostratigraphic datum events. The changes so traced included changes in: type of deep-water sedimentation, accumulation rate, productivity, oxygenation of bottom water and benthic foraminiferal assemblages. Correlation of the palaeoenvironmental changes with the carbon isotope curve and biostratigraphic datum events allowed the comparisons between the various sedimentary areas in the Outer Carpathians, and with other areas of the Western Tethys. Most of the interpreted events around the CTBE were synchronous in the northern branch of the Western Tethys that extended to the Umbria-Marche and Sicily carbonate platforms. These events included: (1) an increase in productivity before the interval with the highest shift in d13C values, (2) the main interval of organic-rich sedimentation (Bonarelli level), (3) a rapid change to oxygenated sediments near the Cenomanian-Turonian (C-T) boundary and continued during the Early Turonian, (4) fluctuations in oxygen content in bottom waters with short intervals of anoxia during the earliest Turonian, (5) deposition of a thick bentonite layer, near the start of the d13C excursion, roughly synchronous with the phase of a positive shift in Pb isotopic compositions in the silicate sediment fraction in one of the Umbria-Marche sections, (6) an interval of extremely low hemipelagic sedimentation with hiatuses near the base of the C-T boundary and during the earliest Turonian, correlated with the maximum rise of the sea level. The presented data from the Outer Carpathians suggest that the OAE-2 could be triggered by enhanced productivity; however, subaerial volcanic eruptions, accompanied by hydrothermal activity and formation of large igneous provinces could also be a factor which enriched the ocean-atmosphere system in CO2. Sluggish deep- water circulation, probably deteriorating through the Late Cenomanian, favoured preservation of organic matter during the latest Cenomanian. The mechanism of rapid oxygenation of bottom waters near the C-T boundary was related to recurrent inflows of (?)saline warm and oxygenated waters.
    Źródło:
    Annales Societatis Geologorum Poloniae; 2007, 77, No 2; 171-191
    0208-9068
    Pojawia się w:
    Annales Societatis Geologorum Poloniae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Mid-Cretaceous spicule-rich turbidites in the Silesian Nappe of the Polish Outer Carpathians : radiolarian and foraminiferal biostratigraphy
    Autorzy:
    Bąk, M.
    Bąk, K.
    Ciurej, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/2058910.pdf
    Data publikacji:
    2005
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Outer Carpathians
    middle-upper Cenomanian
    spicule-rich turbidites
    radiolarians
    foraminifers
    biostratigraphy
    Opis:
    Spicule-rich turbidites are widespread in mid-Cretaceous deep-water flysch of the Subsilesian and Silesian units in the Polish Outer Carpathians. The spicule-richmaterial with an admixture of numerous radiolarian and foraminiferal particles was supplied, together with siliciclastic material, from shallow environments, mostly from the northern margin of the Carpathian Basin. We present new data on the age of these deposits in the Silesian Nappe, where they are distinguished as the Mikuszowice Cherts. This unit is composed of mediumand thick-bedded siliciclastic to calcareous turbidites including bluish cherts in their middle and upper parts and of thin non-calcareous hemipelagic shales.We have studied radiolaria and foraminifera from hemipelagic sediments and spicule-rich turbidites, from two continuous sections in the Barnasiówka Range (BeskidWyspowyMts.) that included theMikuszowice Cherts (31 m thick) and their transition into the surrounding units. The age of the Mikuszowice Cherts was determined taking into account the following radiolarian datum events: (1) the occurrence of Praeconocaryomma lipmanae in the entire unit, (2) the FO (first occurrence) of Hemicryptocapsa tuberosa in the upper part of the unit, (3) the FO of Amphipyndax stocki close to the upper boundary of the unit, (4) the FO of Hemicryptocapsa prepolyhedra in the lowermost part of the overlying Barnasiówka Radiolarian Shale Formation. These datum events appear successively in theWestern Tethys successions within the Rotalipora cushmani planktonic foraminiferal Zone, which corresponds to the middle and upper Cenomanian (except for its uppermost part). The foraminiferal assemblages, in which such taxa as Rotalipora cf. cushmani, R. cf. greenhornensis, whiteinellids and Uvigerinammina praejankoi successively appear, confirm the mid-late Cenomanian age of the spicule-rich turbidites in the Silesian Nappe.
    Źródło:
    Geological Quarterly; 2005, 49, 3; 275--290
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Siliciclastic input into Upper Cenomanian synorogenic sediments of the High-Tatric Unit, Central Western Carpathians (Tatra Mountains); petrography, geochemistry and provenance
    Autorzy:
    Wolska, A.
    Bąk, K.
    Bąk, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/2060546.pdf
    Data publikacji:
    2016
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    petrography
    geochemistry
    Upper Cenomanian
    Zabijak Formation
    High-Tatric Unit
    Central Western Carpathians
    Opis:
    The Upper Cenomanian mixed siliciclastic-carbonate succession of the High-Tatric Unit was deposited during the initial stage of basinal closing of the Tatric area, part of the Zliechov (Križna) Basin (Inner Carpathian domain). As a result of tectonic activity taking place at the northern Veporic margin, pulses of siliciclastic input interrupted marine carbonate sedimentation. The siliciclastic material, part of the Zabijak Formation, has been studied along two sections (Pisana Gully and Zdziarski Gully) in the Western Tatra Mountains. Microfacies, petrographic and geochemical analyses reveal a variability of siliciclastic material composed of various types of granitoids and medium- or high-grade metamorphic rocks, with schists and gneisses. Such interpretation is confirmed by the results of elemental chemical analyses, in which immobile trace elements, such as REE, Th, Cr, Co, Zr, and Y were used as indices for sediment provenance. The parent rocks sustained moderate to intense chemical weathering, documented by chemical weathering indices (CIA, PIA, CIW, R). The weathering occurred in a humid climate with relatively high precipitation that caused strong leaching of particles. Chemical indices related to sorting processes suggest that the recycling of the source material was a minor significance. The siliciclastic input displays a waning upward tendency in the sections, which can be associated with diminishing of the source area by gradual inland progradation of a carbonate platform, caused by a global sea level rise during the Late Cenomanian.
    Źródło:
    Geological Quarterly; 2016, 60, 4; 919--934
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Environmental changes around the Cenomanian-Turonian boundary in a marginal part of the Outer Carpathian Basin expressed by microfacies, microfossils and chemical records in the Skole Nappe (Poland)
    Zmiany w głębokowodnym środowisku brzeżnej części basenu Karpat Zewnętrznych wokół granicy Cenomanu i Turonu wyrażone w zapisie mikrofacji, zespołach mikroskamieniałości i chemizmie utworów w Płaszczowinie Skolskiej
    Autorzy:
    Bąk, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/191678.pdf
    Data publikacji:
    2007
    Wydawca:
    Polskie Towarzystwo Geologiczne
    Tematy:
    Cenomanian-Turonian boundary event
    microfacies
    benthic foraminifers
    bulk geochemistry
    Outer Carpathians
    Polska
    Opis:
    Lithology, microfacies, benthic foraminiferal and bulk chemical analyses of the Spława section in the Skole Nappe, Outer Carpathians (Poland) reflect environmental changes across the Cenomanian-Turonian transi- tion. Biogenic-rich-turbidite sedimentation preceded the organic-rich sedimentation in the Skole Basin, termina- ting in the latest Cenomanian in response to progressive eustatic sea-level rise and to expansion of an oxygen minimum zone. The uppermost Cenomanian black, laminated, organic-rich shale series records the oceanic anoxic event (OAE-2). The benthos-free black non-calcareous shales exhibiting positive excursions of chemical redox indexes are indicative of bottom-water anoxia, interrupted by periods of suboxic conditions with sedimentation of hemipelagic green shales with poor agglutinated foraminiferal assemblages. An extremely low sedimentation rate or even a hiatus and an increase in deep-water circulation causing basin oxygenation resulted in precipitation of a ferromanganese layers and siliceous-manganiferrous variegated shales, as documented by low values of chemical redox indices. However, the lack of benthos and bioturbation, and low values of the Ce/La ratio in the subsequent succession of variegated shales (dominated by green shales) indicate a return to stressed conditions at basin floor with sluggish bottom water circulation, which occasionally resulted in sea floor anoxia with deposition of organic-rich shales. The long-termed well-oxygenated conditions at the basin floor appeared in the Early Turo- nian, as documented by diversified benthic foraminiferal assemblages. The frequency of radiolarian-rich layers and Ba/Al and Ba/Sc ratios increase up-section, reflecting an increase in primary productivity, induced by upwelling circulation.
    Źródło:
    Annales Societatis Geologorum Poloniae; 2007, 77, No 1; 39-67
    0208-9068
    Pojawia się w:
    Annales Societatis Geologorum Poloniae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Evidence of bacteriogenic iron and manganese oxyhydroxides in Albian-Cenomanian marine sediments of the Carpathian realm (Poland)
    Autorzy:
    Bąk, M.
    Bąk, K.
    Górny, Z.
    Stożek, B.
    Powiązania:
    https://bibliotekanauki.pl/articles/191443.pdf
    Data publikacji:
    2015
    Wydawca:
    Polskie Towarzystwo Geologiczne
    Tematy:
    iron
    manganese
    iron-related bacteria
    Albian–Cenomanian
    Silesian Nappe
    Tatra Mts.
    Carpathians
    Opis:
    The Albian and Cenomanian marine sediments of the Silesian and Tatric basins in the Carpathian realm of the Western Tethys contain ferric and ferromanganese oxyhydroxides, visible macroscopically as brown stainings. They coat calcareous bioclasts and mineral clasts, fill pore spaces, or locally form continuous, parallel microlayers, tens of micrometers thick. Light-microscope (LM) and scanning-electron-microscope (SEM) obser- vations show that the coatings contain elongated capsules, approximately 3–5 µm across and enriched in iron and manganese, which may be remnants of the original sheaths of iron-related bacteria (IRB). Moreover, the ferric and ferromanganese staining observed under LM is similar to bacterial structures, resembling the sheaths, filaments and rods formed by present-day bacteria of the Sphaerotilus–Leptothrix group. All of the possible bacteria-like structures are well preserved owing to processes of early diagenetic cementation. If the observed structures are fossil IRB, these organisms could have played an important role in iron and manganese accumulation on the sea floor during Albian–Cenomanian time. The most plausible source of metals for bacterial concentration in the Silesian Basin might have been submarine low-temperature hydrothermal vents, as previously was hypothesized for Cenomanian–Turonian deposits on the basis of geochemical indices.
    Źródło:
    Annales Societatis Geologorum Poloniae; 2015, 85, 2; 371-385
    0208-9068
    Pojawia się w:
    Annales Societatis Geologorum Poloniae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Foraminiferal and radiolarian biostratigraphy of the youngest (Late Albian through Late Cenomanian) sediments of the Tatra massif, Central Western Carpathians
    Autorzy:
    Bąk, K.
    Bąk, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/138987.pdf
    Data publikacji:
    2013
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Albian–Cenomanian
    Tatra massif
    biostratigraphy
    foraminifera
    radiolaria
    alb
    cenoman
    Tatry
    masyw
    biostratygrafia
    otwornice
    promienice
    Opis:
    The foraminiferal and radiolarian biostratigraphy of selected sections of the Zabijak Formation, the youngest sediments of the Tatra massif (Central Western Carpathians), have been studied. Benthic foraminifers, mainly agglutinated species, occur abundantly and continuously throughout the studied succession, while planktic foraminifers are generally sparse. Five planktic and two benthic foraminiferal zones have been recognized. The marly part of the Zabijak Formation comprises the Pseudothalmanninella ticinensis (Upper Albian) through the Rotalipora cushmani (Upper Cenomanian) planktic foraminiferal zones, and the Haplophragmoides nonioninoides and Bulbobaculites problematicus benthic foraminiferal zones. The radiolarians were recognized exclusively in the Lower Cenomanian part of the formation.
    Źródło:
    Acta Geologica Polonica; 2013, 63, 2; 223-237
    0001-5709
    Pojawia się w:
    Acta Geologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-8 z 8

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