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 "carbon isotopes" wg kryterium: Temat

  Lista filtrów
Wyrównaj
Wyświetlanie 1-15 z 53
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:
Origin and maturity of oils in the Ukrainian Carpathians and their Mesozoic basement
Autorzy:
Więcław, D.
Kotarba, M. J.
Kowalski, A.
Koltun, Y. V.
Powiązania:
https://bibliotekanauki.pl/articles/2058970.pdf
Data publikacji:
2012
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Ukrainian Carpathians
Carpathian Foredeep
biomarkers
stable carbon isotopes
Opis:
Geochemical characteristics of 25 oils collected from Skiba Unit of the Outer Carpathians, Boryslav-Pokuttya Unit of the Carpathian Foredeep and their Mesozoic basement in the western Ukraine are presented in the paper. The first recognised oil family consists of almost all oils accumulated in the flysch sequence of the Outer Carpathians and the Carpathian Foredeep which have very similar geochemical characteristics. These oils were generated from Type II or II/III kerogen deposited in clastic sediments. They are low-sulphur and migrated short distances. Slight biodegradation processes are visible only in oils accumulated in shallow deposits in the Skiba Unit. Their source rocks are the Oligocene Menilite Shales from the Boryslav-Pokuttya Unit. Oils from the Kokhanivka and Orkhovychi deposits (the Mesozoic basement of the Carpathian Foredeep) constitute the second family. These oils are extremely heavy, high-sulphur and were generated from high-sulphur Type IIS kerogen deposited in the carbonate environment. The most probable source rocks for these oils are the Upper Jurassic strata. Oil collected from the Vola Blazhivska deposit (the Boryslav-Pokuttya Unit) shows intermediate parameters between the oil families described above. It is characterized by the presence of oleanane and high sulphur content. It was generated from the Menilite Shales containing high-sulphur kerogen. All oils were generated at an early stage or the peak of oil window.
Źródło:
Geological Quarterly; 2012, 56, 1; 158-168
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:
Depth of the water column in relation to carbon isotope ratios in methane in fresh water sediments
Autorzy:
Jędrysek, M. O.
Powiązania:
https://bibliotekanauki.pl/articles/2058951.pdf
Data publikacji:
2005
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
stable carbon isotopes
methane
fresh water sediments
diagenesis
environmental record
Opis:
Methane was collected from the surficial sedimentary layer (0 to about 20 cm) in 45 fresh water lakes in Poland. Sampling was also carried out at various depths of the over lying water column (0.15 to 12 m) between noon and early after noon, on a seasonal basis, between 1992 and 1996. A positive correlation between the depth of the lake water, the δ13 C (CH4) value (from ca. -l.4 to -2.3% per l m depth) and the wider δ13 C (CH4) variation over the thermocline are probably due to: the time of sinking of organic particles resulting in more in tense acetate fermentation in shallower portions of the lake; the temperature variation; differences in the precursors of methane, the diffusion effect, and an increase of bioavailable DIC (dissolved inorganic carbon) at greater depths. Non-seasonal variation of isotope ratios in methane and the depth-isotope ratio correlation show that the lake system is in dynamic equilibrium on a scale of hours and days. Therefore, earlier models of methanogenesis relating and the atmospheric methane isotopic budget, proposed by other authors and based on sampling of methane from sediments, need to be revised. More over, δ13 C (CH4) values higher during seasonal over turn (mixing of benthic and surface waters) than during stagnation, have been observed. This is probably due to the fact that during over turn periods some organic compounds (methane precursors) and methane in the surficial part of sediments, are oxidized with a resalting kinetic isotope effect. It is proposed that oxidation of methane and other organic compounds during seasonal over turn may be responsible for post-depositional lamination observed as pale (autumn over turn) and dark (summer organic-rich unoxic stagnation) millimetres-thick layers in fresh water lake sediments.
Źródło:
Geological Quarterly; 2005, 49, 2; 151-164
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stable carbon and nitrogen isotopes and elemental composition and origin of organic matter from the Neogene Euphrates, Injana and Dibdibba formations in Iraq : discrimination between marine and terrestrial environments
Autorzy:
Awadh, S. M.
Powiązania:
https://bibliotekanauki.pl/articles/2060490.pdf
Data publikacji:
2014
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
stable carbon isotopes
stable nitrogen isotopes
organic matter
marine environment
terrestrial environment
palaeoenvironment
Iraq
Opis:
Three Neogene sedimentary formations reflecting different depositional environments have been investigated for the purpose of diagnosing the isotopic source of the sedimentary organic matter and their palaeoenvironmental significance in discriminating between marine and terrestrial environments. One of these formations is composed of carbonate and marl of a shallow-marine environment (Euphrates Formation), and the other formations are composed of a clastic terrestrial (fluviatile) deposits with some differences in the depositional conditions (Injana and Dibdibba formations). The isotopic δ13C%, δ15N% values, organic carbon (OC) and total nitrogen contents, and atomic C/N ratios are used as evidence of depositional environment. Average δ13C values (in ‰) for the Dibdiba, Injana and Euphrates formations are –25.4, –25.7 and –24.5, respectively; average δ15N values (in ‰) are 4.44, 5.24 and 7.24 and average OC (in wt.%) is 0.13, 0.3 and 1.1, respectively. A significant variation in the stable carbon and nitrogen isotope compositions between fluvial and marine deposits was recorded. The δC, δ15N and C/N values indicate that the organic matter in the Euphrates Formation is of marine origin, whereas it is of terrestrial origin (fluviatile) in the Injana and Dibdibba formations. The C/Natomic values are mostly high in the Injana (37) and Dibddiba formations (51), suggesting greater input and/or preservation of terrestrial organic matter derived from land plants; the shallow-marine environment (Euphrates Formation) was characterized by a low C/N ratio (9) due to the algal-derived organic matter with limited input of terrestrial organic matter.
Źródło:
Geological Quarterly; 2014, 58, 4; 729--736
1641-7291
Pojawia się w:
Geological Quarterly
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:
Origin of natural gases in the autochthonous Miocene strata of the Ukrainian Carpathian Foredeep and its Mesozoic basement
Autorzy:
Kotarba, M. J.
Koltun, Y. V.
Powiązania:
https://bibliotekanauki.pl/articles/191381.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Geologiczne
Tematy:
microbial gases
thermogenic gases
stable carbon isotopes
stable hydrogen isotopes
carbon dioxide
nitrogen
Miocene strata
Mesozoic strata
Opis:
Methane concentrations in natural gases accumulated in the Lower and Upper Badenian and Lower Sarmatian reservoirs of the Bilche-Volytsia Unit in the western part of the Ukrainian Carpathian Foredeep usually exceed 96 vol%. Methane was generated by microbial reduction of carbon dioxide in the marine environment. Microbial methane and ethane were produced mainly during sedimentation of Miocene clays and muds. It is possible that this microbial process continues today. Higher light hydrocarbons (ethane in part, and mainly propane, butanes and pentanes) were generated during the diagenesis and the initial stage of the low-temperature, thermogenic processes from Type III and III/II kerogen deposited in Miocene strata and/or Middle and Upper Jurassic basement rocks. Limited variations in the values of geochemical hydrocarbon indices and stable isotope ratios of methane, ethane and propane with the depth indicate similar gas generation conditions within the whole Miocene succession. The microbial gases (methane and partly ethane) generated during microbial processes within the Miocene strata later migrated to the Upper Jurassic and the Upper Cretaceous (Cenomanian) reservoirs of the Mesozoic basement, and to the bottommost Lower Badenian reservoirs of the analysed Letnia, Orkhovychi, Rudky and Vereshchytsia fields. The low hydrogen concentrations within the Miocene strata as well as within the Upper Jurassic and the Upper Cretaceous (Cenomanian) reservoirs of the Mesozoic basement, and within the bottommost Lower Badenian reservoirs are also related to microbial processes. Carbon dioxide and nitrogen, which are common minor constituents, were generated by both microbial and low-temperature thermogenic processes. Moreover, CO2 also underwent secondary processes, mainly dissolution in water, during migration. At least part of the nitrogen accumulated in the Rudky field, which is remarkably high in N2 (96.9 vol%), is probably of atmospheric origin and was introduced to the reservoir by secondary recovery methods.
Źródło:
Annales Societatis Geologorum Poloniae; 2011, 81, No 3; 425-441
0208-9068
Pojawia się w:
Annales Societatis Geologorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 53

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