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    Wyświetlanie 1-15 z 15
    Tytuł:
    Delta13C of organic atmospheric dust deposited in Wrocław (SW Poland): critical remarks on the passive method
    Autorzy:
    Górka, M.
    Jędrysek, M. O.
    Powiązania:
    https://bibliotekanauki.pl/articles/2060221.pdf
    Data publikacji:
    2008
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    solid organic atmospheric particles
    carbon isotopes
    Opis:
    This paper reports the results of the application of passive collectors to the collection of solid organic atmospheric particles (SOAP) in Wrocław (SW Poland) to carry out stable carbon isotope analyses. delta exp.13C (SOAP) values collected during the vegetation-free period, from November to March, vary in a narrow range from -24.5 to -27.8‰. We show that d13C (SOAP) is able to provide information about atmospheric pollution with respect to different emission sources. delta exp.13C (SOAP) values collected during the period of vegetation growth, from April to October, show a wide range from -20.5 to -26.9‰. The most probable explanations for the 13C- enriched values in summer are that: (i) the SOAP have been contaminated with fresh and decomposed organic matter in the passive collector and/or (ii) SOAP are derived from out side the city or from out side Poland (C4 plant particles). There fore, the d13C (SOAP) may not represent a strictly anthropogenic im pact. The passive collector method for the (SOAP) collection should be applied only in areas with dry deposition of atmospheric dust where deposited organic matter is not de composed in the water contained in collectors. We recommend the use of active sampling methods (hi-volume sampler) to collect SOAP use ful for carbon isotope analyses.
    Źródło:
    Geological Quarterly; 2008, 52, 2; 115-115
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Foraminifers and stable isotope record of the Dubivtsi chalk (upper Turonian, Western Ukraine): palaeoenvironmental implications
    Autorzy:
    Dubicka, Z.
    Peryt, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/2058968.pdf
    Data publikacji:
    2012
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Turonian
    foraminifers
    carbon isotopes
    oxygen isotopes
    biostratigraphy
    palaeoenvironments
    Opis:
    A combined micropalaeontological and stable isotope study of the Dubivtsi chalk in the Western Ukraine indicates its middle late Turonian age. One long-term and clearly distinguishable positive excursion of the isotope curve (d1318
    Źródło:
    Geological Quarterly; 2012, 56, 1; 199-214
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Seasonal and diurnal variations of δ13C and concentration of atmospheric CO2 at Parma, Italy
    Autorzy:
    Longinelli, A.
    Selmo, E.
    Powiązania:
    https://bibliotekanauki.pl/articles/2058957.pdf
    Data publikacji:
    2005
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    atmosphere
    carbon dioxide
    environment
    anthropogenic emissions
    carbon isotopes
    Opis:
    The δ13C of atmospheric CO2 from discrete air samples collected at the University campus, Parma, Italy, was measured at time intervals of about five days over a period of 18 months. Some day and night samples were measured along with three daily time series to evaluate the daily variations of δ13C values and CO2 concentrations. The following patterns were revealed: (1) the least negative δ13C values show a seasonal evolution with slightly more negativevalues during winter and less negative values during summer. Home heating systems probably contribute to this behaviour; (2) four samples collected in down town Parma show more negative values than those collected at the same time at the University campus, probably be cause of car engine pollution; (3) occasionally, quite negative δ13C values were obtained at the campus. The expansion of polluted air masses from down town to the suburban area may be responsible for these negative events; (4) one sample showed a δ13C of -17.67‰. The nearby fields had been extensively manured and the contribution from organic matter fermentation may explain the exceptionally negative result; (5) the diurnal changes in δ13C are relatively low from January to May; (6) in July and September the major daily changes take place in the late evening and in the early morning and are very fast. During the night the CO2 concentration in creases by no more than some 50-60%, this behaviour differing from observations by other authors in different areas; (7) the set of daily samples collected in August shows a different behaviour, clearly related to the heavy rain that lasted for several hours during the night.
    Źródło:
    Geological Quarterly; 2005, 49, 2; 127-134
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Respiration and assimilation processes reflected in the carbon isotopic composition of atmospheric carbon dioxide
    Autorzy:
    Szaran, J.
    Niezgoda, H.
    Trembaczowski, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/146953.pdf
    Data publikacji:
    2002
    Wydawca:
    Instytut Chemii i Techniki Jądrowej
    Tematy:
    atmosphere
    carbon dioxide
    carbon isotopes
    delta-C-13
    respiration
    Opis:
    This paper presents diurnal variations of concentration and carbon isotopic composition of atmospheric carbon dioxide caused by respiration and assimilation processes. Air samples were collected during early and late summer in 1998 in unpolluted area (village Guciow located near the Roztocze National Park, SE Poland) in three different environments: uncultivated field on a hill, a meadow in the Wieprz river valley and a forest. The effect is very strong during intensive vegetation growth on a sunny day and clear night. The largest diurnal variations in atmospheric CO2 concentration and its carbon isotopic composition in June above the meadow were about 480 ppm and 10‰, respectively.
    Źródło:
    Nukleonika; 2002, 47,suppl.1; 59-61
    0029-5922
    1508-5791
    Pojawia się w:
    Nukleonika
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Reconstruction of postglacial paleoproductivity in Long Lake, King George Island, West Antarctica
    Autorzy:
    Yoon, Ho-Il
    Khim, Boo-Keun
    Lee, Kyung
    Park, Yu-Hyeon
    Yoo, Kyu-Cheul
    Powiązania:
    https://bibliotekanauki.pl/articles/2051902.pdf
    Data publikacji:
    2006
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Antarctica
    lake sediment
    paleoclimate
    diatoms
    organic carbon
    carbon isotopes
    Źródło:
    Polish Polar Research; 2006, 27, 3; 189-206
    0138-0338
    2081-8262
    Pojawia się w:
    Polish Polar Research
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Wenlock-Ludlow carbon isotope trend in the Vidukle core, Lithuania, and its relations with oceanic events
    Autorzy:
    Martma, T.
    Brazauskas, A.
    Kaljo, D.
    Kaminskas, D.
    Musteikis, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/2058950.pdf
    Data publikacji:
    2005
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Lithuania
    Silurian
    carbon isotopes
    oceanic events
    sedimentary facies
    Opis:
    A Wenlock to Ludlow terrigenous-carbonate succession in the Vidukle core in Central Lithuania represents a deep shelf environment with a general upwards-shallowing trend, interrupted by brief deepening episodes. The carbon isotope trend, based on 115 whole-rock analyses, shows three main excursions: (1) a major excursion (δ13 C values reach 3.2‰) in the lower Wenlock, (2) low shifts (1.3‰ and 1.6‰) at two levels in the upper most Wenlock Siesartis Formation corresponding to the Monograptus ludensis Biozone, (3) the most prominent excursion (δ13 C values reach 8.2‰) occurs in the upper Ludlow Mituva Fm. The upper Ludlow excursion is dated by the last occurrences of Polygnathoides siluricus below the main shift and the appearance of Ozarkodina wimani and O. crispa above the excursion. The excursion stratigraphically coincides with the Lau oceanic Event and is correlated with the mid-Ludfordian Neocucullograptus kozlowskii-Bohemograptus bohemicus tenuis Biozone. Changes in the carbon isotope trend are in general harmony with some aspects of the rock (CaO, terrigenous component) and fossil content of the section. The data presented are consistent with an arid climate model for the Ludfordian isotope event.
    Źródło:
    Geological Quarterly; 2005, 49, 2; 223--234
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Latest Triassic climate humidification and kaolinite formation (Western Carpathians, Tatric Unit of the Tatra Mts.)
    Autorzy:
    Lintnerová, O.
    Michalik, J.
    Uhlík, P.
    Soták, J.
    Weissová, Z.
    Powiązania:
    https://bibliotekanauki.pl/articles/2060305.pdf
    Data publikacji:
    2013
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    sedimentology
    foraminifers
    clay minerals
    carbon isotopes
    REE
    palaeogeography
    Opis:
    The Tomanová Formation, of Rhaetian age, overlying the Norian Carpathian Keuper in the Tatra Mts. is built of cyclic parasequences of mudstones and sandstones. Quartz (15 to 70 wt.%), kaolinite (13 to 46 wt.%) and 2:1 Al dioctahedral phyllosilicates (dioct 2:1: muscovite, illite, illite/smectite: 5 to 39 wt.%) represent the major mineral phase. The kaolinite/dioct 2:1 ratio decreases upwards in the section (from 4.3 to 0.5) and signals variability in weathering/erosion intensity and changing water salinity. Major and trace elements (LILE, HSFS, REE) indicate a uniform source – felsic rocks located probably in the Vindelician Highlands. The sedimentation rate (83 mm/ky) was controlled by climate. Alternation of dry and humid periods is refered by sedimentary textures and by maturity of quartz (aeolian vs. fluvial grains), and organic matter content and composition (Corg and d13Corg). Authigenic siderite or bethierine documents wet and reduced conditions in the upper part of the Tomanová Formation. The sedimention rate of the marine Dudzinec Formation attained 25 mm/ka and the character of cycles preserved in the sequence is similar as that of the Tomanová Formation (fining upwards parasequences). However, the different clay mineralogy, the recycled character of the silicates, the different d13Corg and elevated imput of carbonate detritus with specific C and O isotopic patterns document a discontinuity in the section. The transgressive character of the Dudzinec Fm. was deduced from the stratigraphic distribution and environmental characteristics of the benthic foraminifera present. Involutinids and spirillinids dominate in the lower part, endothyrinids govern the middle part, and in the upper part nodosariids and Ammodiscus-type microfauna occur. These age-diagnostic microfossils indicate a late Rhaetian age. Sea level rise in the Tatric Zone triggered by thermal expansion of the Central Atlantic Rift was gradual, being affected by input of terrestrial clastic sediment both by freshwater and by wind. The Tatric Triassic sequence in the Western Carpathians helps understanding of the development of sedimentation, palaeoclimate (kaolinite weathering), and palaeogeography of the northernmost Tethyan Domain.
    Źródło:
    Geological Quarterly; 2013, 57, 4; 701--728
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Foraminiferal colonization related to the Zechstein (Lopingian) transgression in the western part of the Wolsztyn Palaeo-Ridge area, Western Poland
    Autorzy:
    Peryt, D.
    Peryt, T. M.
    Raczyński, P.
    Chłódek, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059413.pdf
    Data publikacji:
    2012
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Upper Permian
    Zechstein
    encrusting foraminifers
    carbon isotopes
    oxygen isotopes
    transgression
    breccias
    Opis:
    The basal Zechstein succession in SW Poland is dominated by breccias and/or conglomerates or extraclast-bearing bioclastic limestones, which were deposited during rapid flooding of the pre-existing intracontinental basin in the early Lopingian (Late Permian). Of these, the boulder-cobble breccias and conglomerates are interpreted as deposited in a rocky shore-zone where density flows and upwelling prevailed. The breccias gradually pass up into bryozoan (or other bioclastics) grainstones. The matrix-supported breccias were deposited as large extraclasts and blocks of Carboniferous rock were rolled down or detached from a cliff and were then either embedded into a carbonate sand or formed a framework supplying voids that could be colonized by tubular encrusting foraminifers. These foraminifers abound in all basal Zechstein facies (except in the debris-flow deposits) and are attributed to Palaeonubecularia. The associated faunas include other foraminifers (uniserial and hemigordiopsids), bryozoans, brachiopods, bivalves, gastropods, and microbial deposits. The prolific growth of tubular encrusting foraminifers has resulted from nutrient supply from the basin by upwelling. Botryoidal aragonite cements (also interpreted as due to upwelling) also characterize the basal Zechstein strata, although they were previously reported only from the upper Zechstein Limestone. The ẟI3C values of the basal Zechstein deposits show small variation and oscillated around 4.0%o, suggesting that these deposits are younger than the Kupferschiefer.
    Źródło:
    Geological Quarterly; 2012, 56, 3; 529--546
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Origin of siderites from the Lower Jurassic Ciechocinek Formation from SW Poland
    Autorzy:
    Leonowicz, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059485.pdf
    Data publikacji:
    2007
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Cracow-Silesian Upland
    Lower Jurassic
    siderites
    geochemistry
    carbon isotopes
    oxygen isotopes
    palaeosalinity
    Opis:
    Sideritic rocks, which are characteristic constituents of muddy-silty deposits of the Lower Jurassic Ciechocinek Formation, occur commonly as layers, lenses and small irregular concretions composed of siderite mudstone and siltstone as well as less common lenses of sideritic sandstones. Three types of siderite cement were observed in thin sections: fine-crystalline variety (SF), coarse-crystalline rhombohedra (SR) and fine-crystalline biogenic aggre gates (SA). In all these types BSE analysis revealed compositional zonation of crystals, with in ternal parts enriched in Mg, Mn and Ca and outer zones almost pure siderite. d13C values and chemical composition of siderites combined with the presence of early diagenetic pyrite indicate that siderite crystallized from brackish marine-derived solutions; only in the case of two samples from the lower part of the Ciechocinek Formation the fresh water origin cannotbe excluded. Mn and Fe were supplied by rivers and released by Fe- and Mn-reduction in suboxic zone, whereas Mg and Ca were derived from sea water, which infiltrated into the sediment. Crystal zonation resulted from the diagenetic evolution of pore water as the sediment was buried. Similar composition and development of siderite crystals from different parts of one layer indicate that siderite precipitated simultaneously throughout the whole horizon. Precipitation began from the formation of numerous nuclei and continued by growth of crystals onto them. It could begin already in the iron reduction subzone and continued in the sulphate reduction and methanogenesis zones.
    Źródło:
    Geological Quarterly; 2007, 51, 1; 67-78
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Metodyka analiz izotopowych rozpuszczonego węgla nieorganicznego (DIC) i ich zastosowania w badaniach hydrogeologicznych i środowiskowych
    Methodology and application of stable isotope analysis of dissolved inorganic carbon (DIC) in hydrogeology and environmental studies
    Autorzy:
    Szynkiewicz, A.
    Drzewicki, W.
    Jędrysek, M. O.
    Powiązania:
    https://bibliotekanauki.pl/articles/2074490.pdf
    Data publikacji:
    2006
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    rozpuszczony węgiel nieorganiczny (DIC)
    izotop węgla
    dissolved inorganic carbon
    carbon isotopes
    Opis:
    The analysis of carbon isotope composition of dissolved inorganic carbon (DIC) is widely applied in hydrogeology and environmental studies. The method of analysis is simple and based on conversion of all DIC species to gaseus CO2 under acidic conditions. However, the analytical procedure may involve significant carbon isotope fractionation. Our experimental analysis showed that increasing the time of CO2 extraction influences the increase of ä13C(DIC) value as a result of re-dissolution of CO2 in the water expanded on the vacuum line or/and carbon isotope exchange between the extracted CO2 and the atmospheric CO2. The long time of sample storage yields an increase of ä13C(DIC) value and decrease of DIC concentration. The analytical precision up to š 0,1‰ may be achieved in the case of waters being analyzed few days after sampling. DIC concentration was evaluated according to height of peak 44 in the mass spectrum. The analytical precision of this method was š 2 mgCO2 per dm3. This method is very useful because the measurements of the height of peak 44 and carbon isotope composition of DIC can be performed simultaneously. However, this method is reliable for waters containing more than 4 mg CO2 per dm3
    Źródło:
    Przegląd Geologiczny; 2006, 54, 9; 797-806
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Sedimentary development and isotope analysis of deposits at the Cretaceous/Palaeogene transition in the Paraíba Basin, NE Brazil
    Autorzy:
    Neumann, Virgínio Henrique
    Barbosa, José Antônio
    Nascimento-Silva, Valberlândia Maria
    Sial, Alcides Nobrega
    Filho, Mario
    Powiązania:
    https://bibliotekanauki.pl/articles/94597.pdf
    Data publikacji:
    2009
    Wydawca:
    Uniwersytet im. Adama Mickiewicza w Poznaniu
    Tematy:
    NE Brazil
    Cretaceous-Paleogene boundary
    carbon isotopes
    oxygen isotopes
    Brazylia
    izotop węgla
    izotop tlenu
    Opis:
    New data are presented for three formations (Itamaracá, Gramame and Maria Farinha) and two boundaries (Campanian/Maastrichtian and Maastrichtian/Danian) in the Olinda Sub-basin of the Paraíba Basin. Currently accepted facies models, sequence stratigraphy characterizations, and stable-isotope data of carbon and oxygen are reviewed. The carbonate cement of the Itamaracá Formation sandstones shows carbon- and oxygen-isotope ratios consistent with a shallow-marine depositional environment: δ18O ranges from -0.8 to -2.7‰ PDB, and δ13C ranges from +1 to +2‰ PDB. Within the Itamaracá Formation, a maximum flooding surface at the Campanian/Maastrichtian transition has been identified. During the Maastrichtian, a Highstand System Tract was deposited, which shows an increase in temperature and marine bioproductivity as recorded by stable-isotope values (δ18O from -3 to -5‰ PDB, and δ13C values of -1.2, -0.3, 0.1 and +2.3‰ PDB). Just below the K/Pg boundary, the O-isotope signal indicates three warming phases, alternating with four cooling phases.
    Źródło:
    Geologos; 2009, 15, 2; 103-113
    1426-8981
    2080-6574
    Pojawia się w:
    Geologos
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Terreneuvian stratigraphy and faunas from the Anabar Uplift, Siberia
    Autorzy:
    Kouchinsky, Artem
    Bengtson, Stefan
    Landing, Ed
    Steiner, Michael
    Vendrasco, Michael
    Ziegler, Karen
    Powiązania:
    https://bibliotekanauki.pl/articles/945221.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Instytut Paleobiologii PAN
    Tematy:
    mollusca
    small shelly fossils
    stratigraphy
    carbon isotopes
    cambrian
    terreneuvian
    russia
    siberia
    anabar
    Opis:
    Assemblages of mineralized skeletal fossils are described from limestone rocks of the lower Cambrian Nemakit-Daldyn, Medvezhya, Kugda-Yuryakh, Manykay, and lower Emyaksin formations exposed on the western and eastern flanks of the Anabar Uplift of the northern Siberian Platform. The skeletal fossil assemblages consist mainly of anabaritids, molluscs, and hyoliths, and also contain other taxa such as Blastulospongia, Chancelloria, Fomitchella, Hyolithellus, Platysolenites, Protohertzina, and Tianzhushanella. The first tianzhushanellids from Siberia, including Tianzhushanella tolli sp. nov., are described. The morphological variation of Protohertzina anabarica and Anabarites trisulcatus from their type locality is documented. Prominent longitudinal keels in the anabaritid Selindeochrea tripartita are demonstrated. Among the earliest molluscs from the Nemakit-Daldyn Formation, Purella and Yunnanopleura are interpreted as shelly parts of the same species. Fibrous microstructure of the outer layer and a wrinkled inner layer of mineralised cuticle in the organophosphatic sclerites of Fomitchella are reported. A siliceous composition of the globular fossil Blastulospongia is reported herein and a possible protistan affinity similar to Platysolenites is discussed. New carbon isotope data facilitate correlation both across the Anabar Uplift and with the Terreneuvian Series of the IUGS chronostratigraphical scheme for the Cambrian System. The base of Cambrian Stage 2 is provisionally placed herein within the Fortunian‒Cambrian Stage 2 transitional interval bracketed by the lowest appearance of Watsonella crosbyi and by a slightly higher horizon at the peak of carbon isotope excursion Iʹ from western flank of the Anabar Uplift. Correlation across the Siberian Platform of the fossiliferous Medvezhya and lower Emyaksin formations showing δ¹³C carb excursion Iʹ with the upper Sukharikha Formation containing excursion 5p and upper Ust’-Yudoma Formation containing excursion I is supported herein.
    Źródło:
    Acta Palaeontologica Polonica; 2017, 62, 2; 311-440
    0567-7920
    Pojawia się w:
    Acta Palaeontologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    From carbonate platform to euxinic sea – the collapse of an Early/Middle Devonian reef, Cantabrian Mountains (Spain)
    Autorzy:
    van Loevezijn, G. B. S.
    Raven, J. G. M.
    Powiązania:
    https://bibliotekanauki.pl/articles/94474.pdf
    Data publikacji:
    2017
    Wydawca:
    Uniwersytet im. Adama Mickiewicza w Poznaniu
    Tematy:
    Anoxia
    Basal Choteč Event
    Cantabria
    carbon isotopes
    Eifelian
    Emsian
    anoksja
    Kantabria
    izotopy węgla
    eifel
    ems
    Opis:
    The Santa Lucía Formation represents the major phase in Devonian reef development of the Cantabrian Zone (Cantabrian Mountains, northwest Spain). In the present study the transition from the carbonate platform deposits of the Santa Lucía Formation to the overlying euxinic basinal deposits of the Huergas Formation is described. These transitional strata are connected to the Basal Choteč Event and represent a condensed sedimentation of micritic dark-grey and black limestones with an upward increase of dark shale intercalations with iron mineralisation surfaces and storm-induced brachiopod coquinas. The transitional beds are grouped into a new unit, the Cabornera Bed, which consists of lime-stone, limestone-shale and shale facies associations, representing a sediment-starved euxinic offshore area just below the storm wave base. Four stages in reef decline can be recognised: a reef stage, an oxygen-depleted, nutrient-rich stage, a siliciclastic-influx stage and a pelagic-siliciclastic stage. Additional geochemical and geophysical investigations are needed to verify the results presented herein.
    Źródło:
    Geologos; 2017, 23, 3; 143--161
    1426-8981
    2080-6574
    Pojawia się w:
    Geologos
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Jurassic–Cretaceous transition in the High-Tatric succession (Giewont Unit, Western Tatra Mts, Poland): integrated stratigraphy and microfacies
    Autorzy:
    Lodowski, Damian Gerard
    Pszczółkowski, Andrzej
    Wilamowski, Andrzej
    Grabowski, Jacek
    Powiązania:
    https://bibliotekanauki.pl/articles/2023960.pdf
    Data publikacji:
    2021
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    microfossils
    rock magnetism
    carbon isotopes
    Western Carpathians
    Tatra Mountains
    mikroskamieniałości
    skała magnetyczna
    izotopy węgla
    Karpaty Zachodnie
    Tatry
    Opis:
    Herein are presented the results of detailed bio - (calcareous dinocysts, calpionellids, foraminifers, saccocomids) and chemostratigraphic (δ13C) studies combined with high-resolution microfacies, rock magnetic and gamma-ray spectrometry (GRS) investigations performed on the upper Kimmeridgian-upper Valanginian carbonates of the Giewont succession (Tatricum, Giewont and Mały Giewont sections, Western Tatra Mountains, Poland). The interval studied covers the contact between the Raptawicka Turnia Limestone (RTL) Fm. and the Wysoka Turnia Limestone (WTL) Fm. Their sedimentary sequence is composed of micrites, pseudonodular limestones, cyanoid packstones, lithoclastic packstone and encrinites. A precise correlation with the previously published Mały Giewont section is ensured by biostratigraphy, rock magnetic and GRS logs. The methodology adopted has enabled the recognition of two stratigraphic discontinuities, approximated here as corresponding to the latest Tithonian-early (late?) Berriasian and the early Valanginian. The hiatuses are evidenced by biostratigraphic data and the microfacies succession as well as by perturbations in isotopic compositions and rock magnetic logs; they are thought to result from a conjunction of tectonic activity and eustatic changes. A modified lithostratigraphic scheme for the Giewont and the Osobita High-Tatric successions is proposed. The top of the RTL Fm. falls in the upper Tithonian, where cyanoid packstones disappear. At the base of the WTL Fm. a new Giewont Member is defined as consisting of a basal lithoclastic packstone and following encrinites.
    Źródło:
    Acta Geologica Polonica; 2022, 72, 1; 107--135
    0001-5709
    Pojawia się w:
    Acta Geologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Redox conditions, glacio-eustasy, and the status of the Cenomanian-Turonian Anoxic Event: new evidence from the Upper Cretaceous Chalk of England
    Autorzy:
    Jeans, Christopher V.
    Wray, David S.
    Williams, C. Terry
    Bland, David J.
    Wood, Christopher J.
    Powiązania:
    https://bibliotekanauki.pl/articles/1835600.pdf
    Data publikacji:
    2021
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Cretaceous
    Cenomanian–Turonian Anoxic Event
    eustatic lithocycles
    glacial associations
    redox conditions
    cerium anomalies
    carbon isotopes
    NW Europe
    Japan
    kreda
    cenoman
    turon
    asocjacje
    redoks
    izotopy węgla
    północno-zachodnia Europa
    Japonia
    Opis:
    The nature of the Cenomanian–Turonian Oceanic Anoxic Event (CTOAE) and its δ13 C Excursion is considered in the light of (1) the stratigraphical framework in which the CTOAE developed in the European shelf seas, (2) conclusions that can be drawn from new detailed investigations of the Chalk succession at three locations in England, at Melton Ross and Flixton in the Northern Province where organic-rich ‘black bands’ are present, and at Dover in the Southern Province (part of the Anglo-Paris Basin) where they are absent, and (3) how these conclusion fit in with the present understanding of the CTOAE. The application of the cerium anomaly method (German and Elderfield 1990) at Dover, Melton Ross and Flixton has allowed the varying palaeoredox conditions in the Chalk Sea and its sediments to be related to the acid insoluble residues, organic carbon, δ18O (calcite), δ13C (calcite), δ13C (organic matter), Fe 2+ and Mn2+ (calcite), and P/TiO2 (acid insoluble residue). This has provided evidence that the initial stages of the δ13C Excursion in England were related to (1) a drop of sea level estimated at between 45 and 85 metres, (2) influxes of terrestrial silicate and organic detritus from adjacent continental sources and the reworking of exposed marine sediments, and (3) the presence of three cold water phases (named the Wood, Jefferies and Black) associated with the appearance of the cold-water pulse fauna during the Plenus Cold Event. Conditions in the water column and in the chalk sediment were different in the two areas. In the Northern Province, cerium-enriched waters and anoxic conditions were widespread; the δ13C pattern reflects the interplay between the development of anoxia in the water column and the preservation of terrestrial and marine organic matter in the black bands; here the CTOAE was short-lived (~0.25 Ma) lasting only the length of the Upper Cenomanian Metoicoceras geslinianum Zone. In the Southern Province, water conditions were oxic and the δ13C Excursion lasted to the top of the Lower Turonian Watinoceras devonense Zone, much longer (~1.05 Ma) than in the Northern Province. These differences are discussed with respect to (1) the Cenomanian–Turonian Anoxic Event (CTAE) hypothesis when the ocean-continent-atmosphere systems were linked, (2) limitations of chemostratigraphic global correlation, and (3) the Cenomanian-Turonian Anoxic Event Recovery (CTOAER), a new term to define the varying lengths of time it took different oceans and seas to recover once the linked ocean-continent-atmosphere system was over. The possibility is considered that glacio-eustasy (the glacial control hypothesis of Jeans et al. 1991) with the waxing and waning of polar ice sheets, in association with the degassing of large igneous provinces, may have set the scene for the development of the Cenomanian-Turonian Anoxic Event (CTAE).
    Źródło:
    Acta Geologica Polonica; 2021, 71, 2; 103-152
    0001-5709
    Pojawia się w:
    Acta Geologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
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