Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "siderite" wg kryterium: Wszystkie pola

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-13 z 13
    Tytuł:
    Mechanism of ultrasonic cavitation to improve the effect of siderite on quartz flotation
    Autorzy:
    Yin, Wanzhong
    Cai, Lizheng
    Ma, Yingqiang
    Wang, Ying
    Powiązania:
    https://bibliotekanauki.pl/articles/24085972.pdf
    Data publikacji:
    2023
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    ultrasound treatment
    cover
    fine siderite
    CaCO3 precipitate
    Opis:
    In order to effectively eliminate the effect of fine carbonate minerals on quartz flotation, the influence of fine siderite on quartz flotation was studied as well as the mechanism or role of ultrasonic treatment in the process. The results of adsorption capacity measurement and flotation solution chemical calculation show that fine siderite and its dissolved components have a great influence on the collector consumption and the surface properties of quartz. In addition, SEM, EDS and XPS analysis were used to study the surface morphology and chemical environment changes of quartz with and without ultrasonic treatment. The results of flotation test show that the recovery of quartz increase from 38.79% to 58.38% under the condition that ultrasonic time was 0.5 min and ultrasonic power was200 W. The mechanical effect caused by ultrasonic cavitation can clean the quartz surface to a certain extent and increase its active sites, thus improving the floatability of quartz.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2023, 59, 2; art. no. 165930
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Terrigenous organic matter and formation of siderite in the Bathonian Ore-Bearing Clay Formation at Gnaszyn, Poland : a petrochemical study
    Autorzy:
    Lis, Kacper
    Wojtulek, Piotr
    Lis, Grzegorz
    Jelonek, Iwona
    Powiązania:
    https://bibliotekanauki.pl/articles/2171817.pdf
    Data publikacji:
    2022
    Wydawca:
    Polskie Towarzystwo Geologiczne
    Tematy:
    organic matter
    kerogen
    siderite concretions
    microbial decay
    Jurassic
    Opis:
    The Bathonian Ore-Bearing Clay Formation, outcropping in the Gnaszyn open-pit mine at Częstochowa (Poland), includes several horizons of abundant iron carbonate concretions. The cores of the concretionary bodies commonly contain organic matter (OM), dominated by fragments of wood. These organic particles usually display well-preserved primary structures and occur rarely as more deformed and/or completely degraded fragments. Their original structures are frequently replaced by or filled with secondary mineralization, mostly represented by pyrite. The maceral composition of the OM of the wood fragments is dominated by huminite with subordinate inertinite and resinite. Vitrinite reflectance analyses revealed values lower than 0.45%. The total organic carbon content (TOC) displayed variable results between 2% and 18%. Rock-Eval analyses revealed low amounts of hydrogen (< 45 mg HC/g TOC) and relatively high amounts of oxygen (up to 136 mg CO2/g TOC). Analysed samples contained small quantities of free hydrocarbons (S1 peak < 0.26 mg HC/g rock) as well as hydrocarbons, generated during pyrolysis (S2 peak < 7.05 mg HC/g rock). These features are characteristic for immature type IV kerogen of terrigenous origin. However, the maceral composition and frequent occurrence of siderite affecting the Rock-Eval parameters may indicate that the original kerogen belonged to type III. According to previous authors, the OM of terrigenous origin was delivered to well-oxygenated water of the palaeo-basin in the Częstochowa area. The present data indicate that intensive biodegradation of this OM at shallow burial depleted the oxygen supply within the sediment, driving the pore water into dys- or anoxic conditions. The activity of microorganisms in reducing iron and/or sulphates became the dominant biodegradation reaction, introducing Fe2+ and HCO3- ions into the system. Negative δ13C values in the cortex of the concretions analysed indicate that the bicarbonate consumed in siderite precipitation was supplied by this microbial activity. The reducing microenvironments developed in the sediment and wood fragments acted as nucleation sites for siderite precipitation.
    Źródło:
    Annales Societatis Geologorum Poloniae; 2022, 92, 3; 295--312
    0208-9068
    Pojawia się w:
    Annales Societatis Geologorum Poloniae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Wstępna charakterystyka mineralogiczna czarnych łupków antrakozjowych z obszaru synklinorium śródsudeckiego
    Preliminary mineralogical characteristics of the Anthracosia Shales from the Intra-Sudetic Synclinorium
    Autorzy:
    Wójcik-Tabol, Patrycja
    Dąbek, Jolanta
    Nowak, Grzegorz J.
    Powiązania:
    https://bibliotekanauki.pl/articles/2076184.pdf
    Data publikacji:
    2021
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    węgiel
    synklinorium śródsudeckie
    czarne łupki jeziorne
    syderyt
    kaolinit
    carbon
    Intra-Sudetic Synclinorium
    lacustrine black shales
    siderite
    kaolinite
    Opis:
    Anthracosia Shales within the Pennsylvanian-Lower Permian continental succession from the Intra-Sudetic Synclinorium are lacustrine sediments, represented by black shales intercalated with sandstones/mudstones. Mineral composition of each lithology consists of quartz, feldspar, mica, clay minerals (including kaolinite, the content of which decreases upward the section), and carbonates (calcite and siderite). The section is a continuous record of reduction and rise in terrigenous input. Mineral detritus is least weathered in the uppermost part of the Anthracosia Shales. The sedimentation occurred under dysoxic conditions that were ventilated by bottom currents.
    Źródło:
    Przegląd Geologiczny; 2021, 69, 6; 389--392
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect and mechanism of citric acid on flotation separation of siderite and hematite
    Autorzy:
    Han, Huili
    Yin, Wanzhong
    Yao, Jin
    Li, Dong
    Powiązania:
    https://bibliotekanauki.pl/articles/949693.pdf
    Data publikacji:
    2019
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    siderite
    hematite
    citric acid
    dispersion
    flotation
    E-DLVO theory
    Opis:
    Heterocoagulation can occur between fine siderite and hematite particles, which would result in the low efficiency of their separation during the flotation process. To date, there have been no mature methods to increase their separation efficiency. In this paper, citric acid was used as a regulator to enhance the slurry dispersion efficiency. Micro-flotation, scanning electron microscopy (SEM) analysis, settling tests, particle size measurements, zeta potential measurements and E-DLVO theoretical calculations were conducted in the investigations. A maximum recovery difference (53.98%) between siderite and hematite in their mixtures flotation was obtained. Settling tests confirmed that citric acid contributed to improving the dispersion degree of the slurry. SEM analysis indicated that citric acid could clean the surface of particles and weaken the coagulation between siderite and hematite, which were in line with the results of particle size measurements. The zeta potential measurements and Extended-Derjaguin-Landau-Verwey-Overbeek (E-DLVO) theoretical calculations indicated that the citric acid could adsorb on the siderite and hematite surfaces and decreased the surface charge, resulting in a visible increase of the repulsion energy between siderite and hematite particles. Therefore, citric acid can be applied to remove the easily-ground carbonate minerals first to improve the flotation performance of hematite in the separation process of carbonate-containing iron ores.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2019, 55, 1; 311-323
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Possibilities of Siderite and Barite Concentrates Preparation from Tailings of Settling Pit Nearby Markušovce Village (Eastern Slovakia)
    Możliwości pozyskania koncentratów syderytu i barytu ze stawów osadowych zlokalizowanych koło miejscowości Markušovce (Wschodnia Słowacja)
    Autorzy:
    Hredzak, Slavomir
    Dolinska, Silvia
    Znamenackova, Ingrid
    Lovas, Michal
    Sestinova, Olga
    Powiązania:
    https://bibliotekanauki.pl/articles/318809.pdf
    Data publikacji:
    2019
    Wydawca:
    Polskie Towarzystwo Przeróbki Kopalin
    Tematy:
    odzysk
    wstępna koncentracja grawitacyjna
    separacja magnetyczna
    tailings
    recovery
    gravity pre-concentration
    magnetic separation
    Opis:
    The contribution deals with recovery of useful minerals such as siderite and barite from tailings collected in settling pit nearby Markušovce village (East Slovakia). The material form the pit was subjected to gravity pre-concentration and magnetic separation under laboratory conditions with the aim to verify a possibility of siderite and barite concentrates preparation. A fraction of +0.2–1 mm forming a 40.56 wt% of total grain size scale of the material from the pit and containing 35.71% SiO2, 22.55% Fe2O3, 7,12% Al2O3, 5.48% Ba, and 3.89% SO42– was tested in upgrading process. Thus, 78.18% of SiO2, and 60.41% of Al2O3 at loss 21.70% Fe2O3 and 2.09% of Ba were removed in gravity pre-concentration. The iron concentrate with the content of 44.33% Fe2O3 at Fe recovery of 77.29% in magnetic product was obtained. Barite pre-concentrate with the Ba content of 46.21% at Ba recovery of 91.95% in non-magnetic product was won.
    Artykuł dotyczy możliwości odzysku minerałów użytecznych takich jak syderyt i baryt z odpadów zdeponowanych osadniku w pobliżu miejscowości Markušovce (Słowacja Wschodnia). Materiał z odwiertu poddano wstępnemu wzbogacaniu grawitacyjnemu i separacji magnetycznej w warunkach laboratoryjnych w celu weryfikacji możliwości uzyskania koncentratów syderytu i barytu. Klasa ziarnowa 0,2-1 mm ma wychód 40,56% wagowo i zawartość 35,71% SiO2, 22,55% Fe2O3, 7,12% Al2O3, 5,48% Ba i 3,89% SO42- była poddana wzbogacaniu. Uzyskano koncentrat o uzysku 78,18% SiO2 i 60,41% Al2O3 . We wstępnym wzbogacaniu grawi- tacyjnym usunięto 21,70% Fe2O3 i 2,09% Ba w stężeniu grawitacyjnym. Otrzymano koncentrat żelaza o zawartości 44,33% Fe2O3 przy uzysku Fe 77,29% w produkcie magnetycznym. Uzyskano koncentrat wstępny (produkt niemagnetyczny) barytu o zawartości Ba 46,21% i uzysku 91,95%.
    Źródło:
    Inżynieria Mineralna; 2019, 21, 1; 19-24
    1640-4920
    Pojawia się w:
    Inżynieria Mineralna
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Selective flotation of siderite and quartz from a carbonate-containing refractory iron ore using a novel amino-acid-based collector
    Autorzy:
    Gu, X.
    Zhu, Y.
    Li, Y.
    Han, Y.
    Powiązania:
    https://bibliotekanauki.pl/articles/110222.pdf
    Data publikacji:
    2018
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    flotation
    quartz
    hematite
    siderite
    refractory iron ores
    molecular simulation
    Opis:
    A novel and highly-efficient amino-acid-based collector, α-ethylenediamine lauric acid (α-EDA-LA), was studied to selectively beneficiate carbonate-containing refractory hematite ores. Single mineral and synthetic mixture flotation tests were carried out to investigate its floating performance. Zeta potential, fourier transform infrared spectroscopy (FTIR) and Density Functional Theory-based molecular simulation were used to identify the adsorption mechanism. The flotation results showed that quartz could be collected effectively at pH 11.0-12.0 in the reverse flotation. For siderite, the recovery peaked at 83.4% at pH 8.0, where siderite presented different floatability from magnetite and hematite. Exploiting such difference, the separation of siderite could be achieved. Zeta-potential measurements showed that α-EDA-LA adsorption on the surfaces of siderite and quartz decreased the corresponding zeta potentials at pH of 8.0-10.0 and 8.0-12.0, respectively. This means the adsorption overcome the electrostatic repulsion between α-EDA-LA and the mineral surfaces. The molecular simulation indicated that no chemisorption took place between α-EDA-LA and quartz. FTIR analysis suggested that α-EDA-LA was adsorbed on quartz via hydrogen bonding. The adsorption of α-EDA-LA on siderite surface was dominated by chemisorption, while further enhanced by hydrogen bonding. This study filled the gap in the research on siderite flotation reagents and its adsorption mechanism.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2018, 54, 3; 803-813
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    O syderytach w pokładach węgla warstw rudzkich w niecce chwałowickiej
    About siderites within the coal seams of the Ruda Beds in the Chwałowice Trough
    Autorzy:
    Morga, R.
    Nowak, J.
    Brzezinka, Ł.
    Kądziołka-Gaweł, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/166782.pdf
    Data publikacji:
    2017
    Wydawca:
    Stowarzyszenie Inżynierów i Techników Górnictwa
    Tematy:
    GZW
    niecka chwałowicka
    warstwy rudzkie
    syderyt
    USCB
    Chwałowice Trough
    Ruda beds
    siderite
    Opis:
    Celem pracy była charakterystyka petrograficzna syderytów zidentyfikowanych w wiązce pokładów występujących w stropowej części warstw rudzkich we wschodniej części niecki chwałowickiej GZW. Badania przeprowadzono na siedmiu próbkach skał, pobranych z pokładów 408/1, 408/2 i 409/2. Wykonano badania makroskopowe, mikroskopowe w świetle przechodzącym i odbitym, metodą dyfrakcji rentgenowskiej i fluorescencji rentgenowskiej, a także za pomocą spektroskopii Mössbauera i przy użyciu mikroskopu skaningowego. Stwierdzono, że w badanych syderytach można wyróżnić trzy odmiany, różniące się strukturą i składem chemicznym. Odmiany 1 i 2, o strukturze drobnokrystalicznej, zawierają ok. 44-46% FeO. Odmiana 1 odznacza się przy tym zdecydowanie większą zawartością SiO2 i Al2O3, oraz mniejszą zawartością CaO i MgO, w stosunku do odmiany 2. Odmiana 3 to syderyt o strukturze gruzełkowatej (sferolitycznej). Zawiera on ok. 30% FeO, jak również mniej SiO2 i Al2O3, a więcej CaO i MgO, w stosunku do odmian 1 i 2. Szczególną cechą tej skały jest wysoka zawartość P2O5 (1.47%), związana z obecnością apatytu, występującego w przestrzeniach pomiędzy sferolitami.
    The aim of the study was to describe the petrographic characteristics of siderites occurring within coal seams of the upper part of the Ruda Beds, in the Eastern part of the Chwałowice Trough, in the Upper Silesian Coal Basin. The investigation was carried out on seven samples, collected from seams no.: 408/1, 408/2 and 409/2. Macroscopic and microscopic, in the transmitted and reflected light, X-ray diffraction, X-ray fluorescence, Mössbauer spectroscopy and scanning microscopy examinations were performed. Three types of siderite, which differ by structure and chemical composition, are distinguished. Types 1 and 2, having fine crystalline structure, contain ca. 44-46% of FeO. Type 1 is characterized by significantly higher content of SiO2 and Al2O3, as well as lower content of CaO and MgO, in comparison to the type 2. Type 3 is a siderite having spherulitic structure. It contains ca. 30% FeO, less SiO2 and Al2O3, and more CaO and MgO, in comparison to types 1 and 2. High content of P2O5 (1.47%), connected with apatite occurrence between spherulites, is a characteristic feature of this rock.
    Źródło:
    Przegląd Górniczy; 2017, 73, 7; 23-32
    0033-216X
    Pojawia się w:
    Przegląd Górniczy
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Parametry geotechniczne częstochowskich iłów rudonośnych z rejonu Konopisk (SW obrzeżenie Częstochowy)
    Geotechnical properties of siderite-rich clays from Konopiska municipality (SW margin of Częstochowa)
    Autorzy:
    Dudko-Pawłowska, I.
    Kowalska, M.
    Gawlik, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/2075725.pdf
    Data publikacji:
    2017
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    glina kruszona
    Konopiska
    właściwości geologiczno-inżynierskie
    ore-bearing clay
    geological-engineering properties
    Opis:
    In the vicinity of the Konopiska municipality (SW margin of Częstochowa) ore-bearing clays have been deposited. These formations, only locally covered by younger sediments, constitute direct foundation subsoil, so their geotechnical parameters may conditionate founding possibility of various structures. The paper presents results of a series of experiments (conducted accordingly to PN-B-04481: 1988) dedicated to estimation of the geological-engineering properties of these clays in terms of the possibility of their use as a founding ground or a material to build earth structures. It has been learned that the tested soils contain high amounts of clayey fraction, occur in semi-solid state and show relatively high shear-strength parameters. Their natural water content is close to the optimum one (18-20%), at which a clear peak of the dry density (about 1.7 Mg/m3) is noted. Low colloidal activity proves that they are prone to expansion. All these properties indicate that they can constitute a competent subsoil for typical structures of the first or second geotechnical category, unless obviously the ultimate and serviceability limit states are checked and satisfied for the particular geotechnical case.
    Źródło:
    Przegląd Geologiczny; 2017, 65, 10/2; 848--855
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Role of dissolved mineral species in quartz flotation and siderite solubility simulation
    Autorzy:
    Luo, X.
    Wang, Y.
    Ma, M.
    Song, S.
    Zhang, Y.
    Deng, J.
    Liu, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/109459.pdf
    Data publikacji:
    2017
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    quartz
    solubility
    siderite
    calcium ion
    temperature
    flotation
    Opis:
    Quartz is, in most cases, the major gangue mineral found in the iron ores. Although it can be activated by calcium at strong alkaline pH, quartz nevertheless, reports to the concentrate with Fe when the iron ores contain siderite. It causes a poor concentrate grade and separation between quartz and iron minerals. The effect of siderite on reverse anionic flotation of quartz from hematite was studied in our previous investigations. In this work, the effect of siderite dissolution on the quartz recovery in the froth product and the effect of pH, ions and temperature on siderite dissolution were investigated. Microflotation, PHREEQC simulation, solution chemistry calculation and Fourier transform infrared spectroscopy (FTIR) measurements were conducted. It was observed that the dissolved species of siderite exhibited negative impact on quartz flotation. This influence became weak to some extent by either stripping the dissolved species or shortening dissolution time. Siderite was easily dissolved in the presence of calcium ion under strong alkaline conditions and its solubility increased with increasing the calcium ion concentrate and temperature. When the calcium ion was added as an activator of quartz under strong alkaline conditions (pH>9.96), calcium existed mainly in the CaCO3 precipitation form according to the solubility rule in the presence of siderite. This form could adsorb onto quartz surfaces and further the chemical reaction between starch and quartz was monitored by FTIR measurements. This study provides a further supplement for previous study. A potential strategy is suggested that finding a collector used at low temperature or flotation under neutral (or weak alkaline) medium is helpful to the reverse flotation of iron ores containing siderite.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2017, 53, 2; 1241-1254
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Mikrokonkrecje syderytowe w holoceńskich osadach ujścia rzeki Gwadiana w Portugalii : raport wstępny
    Micro-scale sideritic concretions in Holocene sediments in the Guadiana estuary, Portugal : a preliminary report
    Autorzy:
    Wilamowski, A.
    Boski, T.
    Moura, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/2075017.pdf
    Data publikacji:
    2013
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    siderite
    concretions
    estuarine sediment
    Guadiana River
    Holocene
    syderyt
    konkrecje
    sedymentacja osadów
    rzeka Gwadiana
    holocen
    Opis:
    The authors described micro-scale carbonate concretions occurring at a depth of about 41 m within Holocene sandy sediments filling the Guadiana River paleovalley, representing the transitional fluvial- -estuarine facies. Despite their minute sizes, the micro-concretions show a complex internal structure. Regular distribution of Mg, Mn and Ca can be assigned to a chemical zoning, pointing to precipitation under varying chemical conditions. Based on morphological and chemical peculiarities, four types of concretions can be distinguished. Detrital Fe-Mg-carbonates form nuclei. At first, Mn-rich carbonate precipitated as a coating, which is coherent with the sequence of precipitation of carbonates associated with bacteria-mediated oxidation of organic matter. Subsequently, the main bodies of concretions precipitated as Fe-carbonate (siderite). The last precipitation episode is marked by enrichment in Ca. The XRD patterns show the presence of a mixture of discrete carbonate phases.
    Źródło:
    Przegląd Geologiczny; 2013, 61, 10; 568--575
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Palaeoenvironmental significance of iron carbonate concretions from the Bathonian (Middle Jurassic) ore-bearing clays at Gnaszyn, Kraków-Silesia Homocline, Poland
    Autorzy:
    Witkowska, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/138739.pdf
    Data publikacji:
    2012
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    baton
    bioturbacja
    jura
    konkrecja syderytu
    monoklina śląsko-krakowska
    paleośrodowisko
    Polska
    redoks
    wczesna diageneza
    Bathonian
    bioturbation
    Cracow-Silesia Homocline
    early diagenesis
    Jurassic
    palaeoenvironment
    Phosphate-siderite concretions
    Polska
    Redox boundary
    Siderite concretions
    Opis:
    Iron carbonate concretion horizons are characteristic features of the Bathonian (Middle Jurassic) claystone-mudstone succession at Gnaszyn. They occur in single horizons, which generally represent the same genetic type. The siderite concretions are the main type of iron carbonate concretions at Gnaszyn; a second type is represented by phosphate-siderite concretions. On the basis of the fieldwork, and their petrographical and mineralogical characteristics, the genesis of the concretions and their palaeoenvironmental significance is discussed. The results of this study (based on the localization, mode of occurrence, mineralogy of iron carbonate concretions and also the textural relationship between the concretions and host sediment layers) suggest an early diagenetic origin of the concretions. The preferential occurrence of the concretion horizons in single layers in the ambient sediments was associated with particular conditions of their deposition and early diagenesis, favored by a slower sedimentation rate and more intense bioturbation, and related primarily to the greater availability of reactive iron ions. From the viewpoint of physicochemical conditions the horizons with iron carbonate concretions in the study area reflect the redox boundary between oxic/bioturbated and anoxic/non-bioturbated zones. The conditions favoring the formation of such horizons was possibly due to longer periods of diminished sedimentation rate when the redox boundary remained in the same position within the sediment.
    Źródło:
    Acta Geologica Polonica; 2012, 62, 3; 307-324
    0001-5709
    Pojawia się w:
    Acta Geologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Early diagenetic siderite in the Panorama Point Beds (Radok Conglomerate, Early to Middle Permian), Prince Charles Mountains, East Antarctica
    Autorzy:
    Krajewski, Krzysztof P.
    Gonzhurov, Nikolai A.
    Laiba, Anatoly A.
    Tatur, Andrzej
    Powiązania:
    https://bibliotekanauki.pl/articles/2051608.pdf
    Data publikacji:
    2010
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Antarctica
    Prince Charles Mts
    Radok Conglomerate
    Permian
    siderite
    fresh−water environment
    Źródło:
    Polish Polar Research; 2010, 2; 169-194
    0138-0338
    2081-8262
    Pojawia się w:
    Polish Polar Research
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Unique siderite occurrence in Baltic Sea: a clue to siderite-water oxygen isotope fractionation at low temperatures
    Autorzy:
    Hałas, S.
    Chlebowski, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/2058799.pdf
    Data publikacji:
    2004
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Baltic Sea
    siderite
    oxygen isotopes
    isotope equilibrium
    low temperatures
    water
    Opis:
    electron microprobe (determination of major cation content) and mass spectrometry (delta13 C and delta18 O analysis). The siderite was interpreted as having formed from metallic iron partly protected from free oxygen access by wood tar with delta13 C = -24 0/00 and from biogenic CO2 produced from this organic matter. Inasmuch as the siderite has highly positive delta3 C values ranging from 8.05 to 15.41 0/00, we deduced that extremely isotopically heavy CO2 was generated in the process of biogenic decomposition of the organic matter. It was found that the delta18 O values of siderite (26.58 to 27.74‰ vs. VSMOW) fit very well to the recalculated curve of Becker (1971) [formula] and to published extrapolated experimental data.
    Źródło:
    Geological Quarterly; 2004, 48, 4; 317--322
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-13 z 13

      Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies