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 "geochemistry" wg kryterium: Temat

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-6 z 6
    Tytuł:
    Palaeofacies and biomarker characteristics of Paleogene to Neogene rocks in the Makassar Straits, Indonesia
    Autorzy:
    Sutadiwiria, Yarra
    Hamdani, Ahmad Helman
    Sendjaja, Yoga Andriana
    Haryanto, Iyan
    Siahaan, Yeftamikha
    Siahaan, Mordekhai
    Powiązania:
    https://bibliotekanauki.pl/articles/94325.pdf
    Data publikacji:
    2019
    Wydawca:
    Uniwersytet im. Adama Mickiewicza w Poznaniu
    Tematy:
    geochemistry
    palaeoenvironment
    taraxastane
    oleanane
    geochemia
    paleośrodowisko
    Indonezja
    Opis:
    Borehole K-1 is an exploratory well that was drilled in the North Makassar Basin (West Sulawesi) in 2011. Gas chromatography (GC) and gas chromatography-mass chromatography (GC-MS) analyses have been conducted on extracts from well cuttings from the Paleogene to Neogene interval in order to investigate the characteristics of biomarkers present. Although the well was drilled with oil-based mud and gas chromatographic analysis reveals that the alkane fractions are heavily contaminated, detailed investigation of biomarkers in these rock extracts and comparison with biomarkers in the oil-based mud has revealed that, while there are hopane and sterane biomarkers in the mud, there are also a discrete set of biomarkers that are indigenous to the rocks. These include oleanane, bicadinanes, taraxastane and other higher-plant-derived triterpanes. The presence of these compounds in environments that range from bathyal to marginal marine and even to lacustrine, shows the extent of reworking of terrestrial material into aquatic settings in this region during the Paleogene and Neogene and provides further evidence of a predominance of terrestrial material, even in deep-marine settings, with little ‘in-situ’ material noted. These findings have important implications for the use of biomarkers as indicators of palaeoenvironment in both source rocks and oils.
    Źródło:
    Geologos; 2019, 25, 1; 75-90
    1426-8981
    2080-6574
    Pojawia się w:
    Geologos
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Calibrated geochemical ages of the Baltic Artesian Basin groundwater
    Autorzy:
    Samalavičius, Vytautas
    Arustienė, Jurga
    Powiązania:
    https://bibliotekanauki.pl/articles/2204366.pdf
    Data publikacji:
    2022
    Wydawca:
    Uniwersytet im. Adama Mickiewicza w Poznaniu
    Tematy:
    groundwater dating
    isotope geochemistry
    radiocarbon
    radiokrypton
    datowanie wód podziemnych
    geochemia izotopowa
    radiowęgiel
    Opis:
    For the present study, geochemical ages were derived from radiocarbon and radiokrypton age calibration with ground-water chemical contents (Na+, K+, Mg2+, Ca2+, Cl−, SO42−, HCO3−). Geochemical ages may fill the dating gap (40–150 ka) between the isotope techniques mentioned. A case study of groundwater in the Baltic Artesian Basin has involved geochemical age calibration, data filtering (such as regional subdivision of the basin for more accurate results) and geochemical dating of groundwater of unknown age. Various approaches to interpretations of geochemical age results could be used. Bicarbonate and sulphate are sensitive to the hydrochemical environment and should be omitted from geochemical age calculations. Modern fresh groundwater samples should also be excluded from calibration in order to obtain more reliable trend lines. Calcium-sodium cation exchange occurs in deep aquifers and may be used for geo- chemical age determination of fossil groundwater.
    Źródło:
    Geologos; 2022, 28, 3; 179--189
    1426-8981
    2080-6574
    Pojawia się w:
    Geologos
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Characteristics of the Ahmadabad hematite/barite deposit, Iran – studies of mineralogy, geochemistry and fluid inclusions
    Autorzy:
    Babaei, A. H.
    Ganji, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/94546.pdf
    Data publikacji:
    2018
    Wydawca:
    Uniwersytet im. Adama Mickiewicza w Poznaniu
    Tematy:
    geochemistry
    trace elements
    rare earth elements
    Semnan
    geochemia
    pierwiastki śladowe
    pierwiastki ziem rzadkich
    REE
    Opis:
    The Ahmadabad hematite/barite deposit is located to the northeast of the city of Semnan, Iran. Geostructurally, this deposit lies between the Alborz and the Central Iran zones in the Semnan Subzone. Hematite-barite mineralisation occurs in the form of a vein along a local fault within Eocene volcanic host rocks. The Ahmadabad deposit has a simple mineralogy, of which hematite and barite are the main constituents, followed by pyrite and Fe-oxyhydroxides such as limonite and goethite. Based on textural relationships between the above-mentioned principal minerals, it could be deduced that there are three hydrothermal mineralisation stages in which pyrite, hematite and barite with primary open space filling textures formed under different hydrothermal conditions. Subsequently, in the supergene stage, goethite and limonite minerals with secondary replacement textures formed under oxidation surficial conditions. Microthermometric studies on barite samples show that homogenisation temperatures (TH) for primary fluid inclusions range from 142 to 256°C with a temperature peak between 200 and 220°C. Salinities vary from 3.62 to 16.70 NaCl wt% with two different peaks, including one of 6 to 8 NaCl wt% and another of 12 to 14 NaCl wt%. This indicates that two different hydrothermal waters, including basinal and sea waters, could have been involved in barite mineralisation. The geochemistry of the major and trace elements in the samples studied indicate a hydrothermal origin for hematite and barite mineralisation. Moreover, the Fe/Mn ratio (>10) and plots of hematite samples of Ahmadabad ores on Al-Fe-Mn, Fe-Mn-(Ni+Co+ Cu)×10, Fe-Mn-SiX2 and MnO/TiO2 – Fe2O3/TiO2 diagrams indicate that hematite mineralisation in the Ahmadabad deposit occurred under hydrothermal conditions. Furthermore, Ba and Sr enrichment, along with Pb, Zn, Hg, Cu and Sb depletion, in the barite samples of Ahmadabad ores are indicative of a low temperature hydrothermal origin for the deposit. A comparison of the ratios of LaN/YbN, CeN/YbN, TbN/LaN, SmN/NdN and parameters of Ce/Ce* and La/La* anomalies of the hematite, barite, host volcanic rocks and quartz latite samples to each other elucidate two important points: 1) the barite could have originated from volcanic host rocks, 2) the hematite could have originated from a quartz latite lithological unit. The chondrite normalised REE patterns of samples of hematite barite, volcanic host rocks and quartz latite imply that two different hydrothermal fluids could be proposed for hematite and barite mineralisation. The comparison between chondrite normalised REE patterns of Ahmadabad barite with oceanic origin barite and low temperature hydrothermal barite shows close similarities to the low temperature hydrothermal barite deposits.
    Źródło:
    Geologos; 2018, 24, 1; 55-68
    1426-8981
    2080-6574
    Pojawia się w:
    Geologos
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Factors influencing temporal changes in chemical composition of biogenic deposits in the middle Tążyna River Valley (Kuyavian Lakeland, central Poland)
    Autorzy:
    Okupny, D.
    Rzepecki, S.
    Borówka, R. K.
    Forysiak, J.
    Twardy, J.
    Fortuniak, A.
    Tomkowiak, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/94501.pdf
    Data publikacji:
    2016
    Wydawca:
    Uniwersytet im. Adama Mickiewicza w Poznaniu
    Tematy:
    lake sediments
    peat
    geochemistry
    human activity
    Central Europe
    osady jeziorne
    torf
    geochemia
    aktywność ludzka
    centralna Europa
    Opis:
    The present paper discusses the influence of geochemical properties on biogenic deposits in the Wilkostowo mire near Toruń, central Poland. The analysed core has allowed the documentation of environmental changes between the older part of the Atlantic Period and the present day (probably interrupted at the turn of the Meso- and Neoholocene). In order to reconstruct the main stages in the sedimentation of biogenic deposits, we have used stratigraphic variability of selected litho-geochemical elements (organic matter, calcium carbonate, biogenic and terrigenous silica, macro- and micro-elements: Na, K, Mg, Ca, Fe, Mn, Cu, Zn, Pb, Cr and Ni). The main litho-geochemical component is CaCO3; its content ranges from 4.1 per cent to 92 per cent. The variability of CaCO3 content reflects mainly changes in hydrological and geomorphological conditions within the catchment area. The effects of prehistoric anthropogenic activities in the catchment of the River Tążyna, e.g., the use of saline water for economic purposes, are recorded in a change from calcareous gyttja into detritus-calcareous gyttja sedimentation and an increased content of lithophilous elements (Na, K, Mg and Ni) in the sediments. Principal component analysis (PCA) has enabled the distinction the most important factors that affected the chemical composition of sediments at the Wilkostowo site, i.e., mechanical and chemical denudation processes in the catchment, changes in redox conditions, bioaccumulation of selected elements and human activity. Sediments of the Wilkostowo mire are located in the direct vicinity of an archaeological site, where traces of intensive settlement dating back to the Neolithic have been documented. The settlement phase is recorded both in lithology and geochemical properties of biogenic deposits which fill the reservoir formed at the bottom of the Parchania Canal Valley.
    Źródło:
    Geologos; 2016, 22, 2; 121-136
    1426-8981
    2080-6574
    Pojawia się w:
    Geologos
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Geochemistry and ore potential of the Almoughlagh batholith, western Iran
    Autorzy:
    Zamanian, Hassan
    Asadollahi, Behrooz
    Powiązania:
    https://bibliotekanauki.pl/articles/94586.pdf
    Data publikacji:
    2013
    Wydawca:
    Uniwersytet im. Adama Mickiewicza w Poznaniu
    Tematy:
    Fe-skarn mineralisation
    Almoughlagh batholith
    metaluminous
    geochemistry
    skarn ore potential
    Baba Ali pluton
    geochemia
    Baba Ali
    Almoughlagh
    Opis:
    The Almoughlagh batholith intruded the dioritic Baba Ali pluton during the Oligo-Miocene; the pluton and is now exposed as a big enclave within the batholith. The pluton intruded the Songhor Series during the Late Kimmeridgian (~136 Ma) orogeny. The intrusion by the batholith transformed the diorite to metadiorite and the impure carbonate units of the Songhor Series. The batholith consists of rock types such as quartz syenite and syenogranite, which have a low average quartz content, and which are metaluminous to peraluminous and calc-alkaline in composition. Comparison of the compositions of the Almoughlagh batholith and the pluton with its Cu, Mo, Fe, Sn, W, Au, and Zn skarn deposits, indicates that the Baba Ali diorite geochemically shows much resemblance with those which could bring about Fe-Cu skarn mineralization, whereas the compositions of the Almoughlagh granitoids resembles those of the plutons associated with Mo and Zn skarn deposits. The associated hydrothermal activity related to the Almoughlagh batholith culminated in magnetite mineralisation in the Baba Ali and the Chenar mines in which copper mineralisation also is considerable.
    Źródło:
    Geologos; 2013, 19, 3; 229-242
    1426-8981
    2080-6574
    Pojawia się w:
    Geologos
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Geochemistry and fluid-inclusion microthermometry of the Farsesh barite deposit, Iran
    Autorzy:
    Zarasvandi, A.
    Zaheri, N.
    Pourkaseb, H.
    Chrachi, A.
    Bagheri, H.
    Powiązania:
    https://bibliotekanauki.pl/articles/94476.pdf
    Data publikacji:
    2014
    Wydawca:
    Uniwersytet im. Adama Mickiewicza w Poznaniu
    Tematy:
    hydrothermal barite
    ICP-MS analysis
    geochemistry
    fluid inclusions
    Sanandaj-Sirjan zone
    Iran
    hydrotermalny baryt
    ICP-MS
    geochemia
    inkluzje fluidalne
    Opis:
    The Permian carbonate-hosted Farsesh barite deposit is located southeast of the City of Aligudarz in the prov-ince of Lorestan, Iran. Structurally, this deposit lies in the Zagros metallogenic belt and the Sanandaj-Sirjan Zone. Barite mineralisations occur as open-space filling veins, and as massive and replacement ores along fractures, faults and shear zones of the Permian carbonate host rocks. In order to determine the structure, in addition to pe-trographic and fluid-inclusions studies, an ICP-MS analysis was carried out in order to measure the major as well as the trace and rare earth elements. The Farsesh barite deposit has a simple mineralogy, of which barite is the main mineral, followed by calcite, dolomite, quartz, and opaque minerals such as Fe-oxides. Replacement of bar-ite by calcite is common and is more frequent than space-filling mineralisation. Sulphide minerals are minor and mainly consist of chalcopyrite and pyrite, which are altered by weathering to covellite, malachite and azurite. Petrographic analysis and micro-thermometry were carried out on the two-phase liquid/vapour inclu-sions in ellipsoidal or irregularly shaped minerals ranging in size from 5–10 μm. The measurements were conducted on fluid inclusions during the heating and subsequent homogenisation in the liquid phase. The low homogenisation temperatures (200–125°C) and low to moderate salinity (4.2–20 eq wt% NaCl) in-dicate that the barite had precipitated from hydrothermal basinal water with low to moderate salinity. It appears from the major and trace elements that geochemical features such as Ba and Sr enrichment in the barite samples was accompanied by depletion of Pb, Zn, Hg, Cu and Sb. The geochemistry of the rare earth elements, such as low ΣREE concentrations, LREE-enrichment chondrite-normalised REE patterns, the negative Ce and positive Eu anomalies, the low Ce/La ratio and the positive La and Gd anomalies, suggest that the Farsesh barite was deposited from hydrothermally influenced sea water. The Farsesh deposit contains low-temperature hydrothermal barite. The scatter plots of the barite (close to sea water) in different areas on the CeN/SmN versus CeN/YbN diagram support the possibility that the barite was formed from seawater-bearing hydrothermal fluids.
    Źródło:
    Geologos; 2014, 20, 3; 201-214
    1426-8981
    2080-6574
    Pojawia się w:
    Geologos
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-6 z 6

      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