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    Wyświetlanie 1-36 z 36
    Tytuł:
    U-Pb and K-Ar geochronology of the subvolcanic rock pebbles from the Cretaceous and Paleogene gravelstones and conglomerates of the Pieniny Klippen Belt (Carpathians; Poland, Slovakia) – relevance for tectonic evolution and palaeogeography
    Autorzy:
    Poprawa, Paweł
    Krobicki, Michał
    Nejbert, Krzysztof
    Krzemińska, Ewa
    Armstrong, Richard
    Pecskay, Zoltan
    Powiązania:
    https://bibliotekanauki.pl/articles/24202117.pdf
    Data publikacji:
    2023
    Wydawca:
    Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
    Tematy:
    Pieniny Klippen Belt
    geochronology
    palaeogeography
    Opis:
    In the Pieniny Klippen Belt (PKB), the Cretaceous and Paleogene conglomerates and cohesive debrites commonly contain pebbles and blocks of the subvolcanic rocks among other, mainly sedimentary rocks (e.g. multicoloured sandstones, oolitic limestones, dark bivalve coquinas, dolostones, etc.). This detritus was interpreted as derived from the Andrusov Ridge located south of the PKB basin (Birkenmajer, 1988). Age of these subvolcanic rocks, regarded to represent subduction-related igneous activity, was previously constrained by K-Ar whole rock dating as c. 140–90 Ma, leading to suggestion that during Late Jurassic to Early Cretaceous PKB basin developed on oceanic lithosphere, subducted during at the end of Early Cretaceous (Birkenmajer, 1988). Within this study, the geochemical composition, the K-Ar whole rock age and the U-Pb zircon ages of the above mentioned subvolcanic rocks were studied. The pebbles are well rounded. They are represented by granitic and subvolcanic andesitic-type rocks (mainly andesite, basaltic andesite, basaltic trachyandesite, trachyandesite and rhyolitic pebbles, and rare dacite, tephrite, trachybasaltic and basaltic pebbles). Domination of andesitic pebbles, bimodal spectrum of volcanic rocks with high content of SiO2 (rhyolites, dacites) and Na2O and K2O within mafic and transitional ones is observed. Their petrographic character and geochemical analysis of concentration of rare elements with MgO > 2% ratio and La/Yb 4–35, Sc/Ni < 1.5, Sr/Y < 20, Ta/Yb > 0.1, Th/Yb > 1 values, indicate magmatic island arc of active continental margin similar to Andean-type subduction regime. The K-Ar whole rock dating was performed for 17 samples. The obtained ages cover mainly the Early Cretaceous time span, with the most data representing the Barremian-Albian, therefore are coherent with Birkenmajer (1988) results. However, the U-Pb SHRIMP zircon dating reveled different results. Most of the analyzed subvolcanic rock samples (9) give ages in the narrow range of c. 270–266 Ma. The ages are based on concordant data with amount of measured point in a range of 20–30, and are characterized by low error bars, usually lower than ±2 Ma. In addition, one sample of subvolcanic rock gave lower quality results, with a few youngest, partly concordant, zircons grains giving the age of 251.0 Ma ±8.5 Ma. Moreover, one sample of orthogenesis was analyzed, which is regarded to represent crust on which the volcanic arc developed. In this case the U-Pb SHRIMP zircon dating result is 493.9 Ma ±4.1 Ma. We regard these pebbles/blocks to be derived from the Inner Carpathians, assuming therefore lack of the Andrusov Ridge located south of the PKB basin (comp. Plašienka, 2018). The results of K-Ar whole rock dating is representative for intensive diagenetic overprint, rather than age of the rock. The U-Pb data clearly indicate, that subduction-related magmatic arc developed during the middle Permian (Guadalupian). This follows, that the oceanic crust was of the middle Permian or older age, and thus cannot be related to the Jurassic-Early Cretaceous development of the PKB basin. The magmatic arc was presumably connected with southern margin of Laurusia and subduction of oceanic crust of the Paleotethys (proto-Vardar Ocean?).
    Źródło:
    Geotourism / Geoturystyka; 2023, 1-2 (72-73); 58--58
    1731-0830
    Pojawia się w:
    Geotourism / Geoturystyka
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Early Carboniferous (~337 Ma) granite intrusion in Devonian (~400 Ma) ophiolite of the Central-European Variscides
    Autorzy:
    Kryza, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059145.pdf
    Data publikacji:
    2011
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Variscides
    ophiolites
    SHRIMP zircon geochronology
    Opis:
    The Central-Sudetic ophiolites comprise mafic-ultramafic complexes around the E and S edges of the Góry Sowie Massif in SW Poland and are recognized as fragments of Devonian (~400 Ma old) oceanic crust. They contain small rodingite bodies and tectonized granite dykes that potentially can highlight the igneous, metamorphic and structural development of the ophiolitic suites. The granite dykes have been tentatively correlated with the Variscan granitoids of the Strzegom-Sobótka Massif to the north. However, new U-Pb SHRIMP zircon data for granites from the serpentinite quarry at Jordanów show a concordia age of 337 š4 Ma for the main zircon population, and of 386 š10 Ma for minor inheritance. Thus, the age of the granite is considerably older than the ages of the Strzegom-Sobótka granitoids, dated at ~310-294 Ma. The granite dyke has a similar age as some other granitoids found near the ophiolitic fragments, e.g., the Niemcza granitoids to the south, dated at 338 +2/-3 Ma; these older granitoids all represents a relatively early stage of granitoid magmatism recorded in that part of the Variscan Orogen. The age of the granitoid dyke within serpentinites confirms that the Paleozoic ophiolites were incorporated into the continental crust already in early Visean times.
    Źródło:
    Geological Quarterly; 2011, 55, 3; 213-222
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Neoproterozoic pegmatite from Skoddefjellet, Wedel Jarlsberg Land, Spitsbergen: Additional evidence for c. 640 Ma tectonothermal event in the Caledonides of Svalbard
    Autorzy:
    Majka, Jarosław
    Larionov, Alexander N.
    Gee, David G.
    Czerny, Jerzy
    Pršek, Jaroslav
    Powiązania:
    https://bibliotekanauki.pl/articles/2051474.pdf
    Data publikacji:
    2012
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Arctic
    Svalbard
    zircon
    monazite
    uraninite
    geochronology
    Źródło:
    Polish Polar Research; 2012, 1; 1-17
    0138-0338
    2081-8262
    Pojawia się w:
    Polish Polar Research
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    K/Ar geochronology of igneous amphibole phenocrysts in Miocene to Pliocene volcaniclastics, Styrian Basin, Austria
    Autorzy:
    Bojar, H. P.
    Bojar, A. V.
    Hałas, S.
    Wójtowicz, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/2060550.pdf
    Data publikacji:
    2013
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    geochronology
    igneous amphibole
    volcanic tuffs
    Styrian Basin
    Opis:
    We present fifteen new K/Ar ages on amphibole phenocrysts of Neogene volcaniclastic rocks from the Styrian Basin, Austria. The westernmost sub-basin of the Pannonian Basin is the Styrian Basin, which hosts a large number of phreatomagmatic tuff occurrences beside Middle Miocene shield volcanoes and Pliocene effusive alkaline volcanic rocks. The investigated tuffs contain the well-known mantle xenoliths and frequent amphibole and pyroxene phenocrysts. The new K/Ar ages indicate that the Late Miocene phreatomagmatic volcanism started in Pontian (7.51 Ma) and ended in Romanian (2.73 Ma) times. The complete interval of the youngest volcanism in the Styrian Basin covers 5.8 Ma, similar to the volcanism of the western part of the Pannonian Basin and the Nógrád/Novohrad area (West Carpathians). The dated volcanic occurrences display NNW–SSE oriented arrays which are approximately parallel to the Auersbach basinal high zone. The new data indicate that the Late Miocene to Pliocene volcanism of the Styrian Basin is synchronous with the onset of a regional compressional event and eastward tilting of the Styrian basin fill.
    Źródło:
    Geological Quarterly; 2013, 57, 3; 405--416
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Zircon U-Pb ages of granitoid apophyses in the western part of the Kłodzko–Złoty Stok Granite Pluton (SW Poland)
    Autorzy:
    Mikulski, S.Z.
    Williams, I. S.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059727.pdf
    Data publikacji:
    2014
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Variscan granitoids
    apophyses
    zircon
    SHRIMP geochronology
    Sudetes
    Opis:
    Granitoids from the Graniec–Bardo and Myszak apophyses of the Kłodzko–Złoty Stok (KZS) Granite Pluton that intrude the Upper Paleozoic flysch of the Bardo Unit have zircon U-Pb ages, measured by SHRIMP, of 341.6 ± 2.8 Ma and 341.4 ± 2.2 Ma, respectively. These results augment our previous dating that recorded a short period of Middle Mississippian (Visean) hypabyssal magmatism that produced a variety of KZS igneous rocks of different compositions between ca. 341 and 331 Ma. The Graniec–Bardo and Myszak apophyses belong to the earliest stage of the pluton emplacement. Geochemical and petrographic studies of the dated samples indicate that they are biotite- and hornblende-rich tonalite and syenogabbro of diverse composition and typical of rocks originating from hybrid magmas formed in the geotectonic transition from an early stage collisional granitoid emplacement to its fast orogenic uplift. The polymetallic auriferous ore mineralisation of contact metasomatic type found in intimate contact with the Graniec–Bardo apophysis near Bardo Śląskie may also be of Visean age.
    Źródło:
    Geological Quarterly; 2014, 58, 2; 251--262
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Geochemistry and geochronology of the Jawornik granitoids, Orlica–Śnieżnik Dome, Sudetes, Poland
    Autorzy:
    Białek, Dawid
    Powiązania:
    https://bibliotekanauki.pl/articles/2060123.pdf
    Data publikacji:
    2020
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Jawornik granitoids
    geochemistry
    geochronology
    Sudetes
    Variscan
    granitoids
    Opis:
    The Jawornik granitoids intrude, in vein-like form, a sequence of a polymetamorphic metavolcanic and metapelitic rocks of the Orlica-Śnieżnik Dome, Sudetes, Poland. This paper provides whole-rock geochemical data, sensitive high-resolution ion microprobe (SHRIMP) U-Pb zircon geochronological data as well as 40Ar-39Ar age determinations to constrain the genetic and temporal relationships of the different rock types forming these veins. Based on macroscopically visible features of the granitoids and their relationship with tectonic structures visible in the country rocks, four varieties of the Jawornik granitoids have been distinguished: amphibole- and biotite-bearing granites (HBG), biotite-bearing granites (BG), biotite- and muscovite-bearing granites (BMG) and muscovite-bearlng granites (MG). The Jawornik granitoids as a whole show a limited but significant variation in major element chemical composition, with SiO2 ranging from 65 to 76 wt.% (average 69.16 wt.%, n = 24). They are subalkalic, peraluminous and calc-alkaline [average A/CNK = 1.07, average (Na2O + K2O) = 7.75, average (Fe2O3t/(Fe2O3t + MgO) = 0.59]. Close inspection of their geochemical parameters showed that the samples investigated can be subdivided into two groups. The first group, the HBG, BG, and BMG varieties, comprising most of the granitoids in the Złoty Stok-Skrzynka Tectonic Zone, were formed by melting of greywackes or/and amphibolites. The MG, belonging to the second group, were formed by partial melting of a more felsic source. The HBG yielded a zircon U-Pb age of 351 ±1.3 Ma and well-defined Ar-399Ar plateau ages for hornblende (351.1 ±3.9 Ma) and coexisting biotite (349.6 ±3.8 Ma), indicating probably the oldest magmatic event in this region. Zircons from the MG, the youngest rock variety on the basis of their relationship with the tectonic structures in the host rocks yielded a U-Pb age of 336.3 ±2.4 Ma, though based on three points only. The biotites and muscovites from the BMG have Ar-39Ar plateau ages of 344.1 ±4.7 Ma and 344.6 ±3.8 Ma, respectively. These data, in combination with already published isotopic ages, suggest that the Jawornik granitoids intruded host rocks of the Orlica-Śnieżnik Dome in three stages, at ~350, ~344 and ~335 Ma.
    Źródło:
    Geological Quarterly; 2020, 64, 4; 942--957
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    New 40Ar-39Ar age constrains for magmatic and hydrothermal activity in the Holy Cross Mts. (southern Poland)
    Autorzy:
    Nawrocki, J.
    Salwa, S.
    Pańczyk, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/2060553.pdf
    Data publikacji:
    2013
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Ar-Ar geochronology
    diabases
    mineralization
    Holy Cross Mountains
    Opis:
    New 40Ar-39Ar isotope ages of diabase intrusions from the Holy Cross Mountains (Poland) confirm the presence of at least two events of Paleozoic magmatic activity in the study area. The oldest, latest Silurian/earliest Devonian (ca. 424–416 Ma) episode is recorded by a diabase from the Bardo Syncline (Zarobiny PIG-1 borehole) in the Kielce Region. A younger, Serpukhovian (ca. 331–323 Ma) event is documented by a diabase from the Milejowice-1 borehole drilled in the Łysogóry Region. The diabase intrusion penetrated by the Wzorki-1 borehole, also located in the Łysogóry Region, is most probably of the same age. It provided, however, consistent mid-Triassic (243 Ma) 40Ar-39Ar isotopic age reflecting its pervasive hydrothermal alteration. The first stage of the post-Caledonian hydrothermal activity in the Holy Cross Mts. which produced polymetallic copper and iron-bearing mineralisation may be linked with the younger magmatic phase defined here. The second stage of post-Caledonian hydrothermal activity in the Holy Cross Mts., associated with the lead-zinc mineralisation, may be correlated with the Middle Triassic hydrothermal event recorded in the Wzorki diabase. Suggestions of temporal relationships between magmatic/hydrothermal activities and mineralisation events should, however, be constrained by further detailed geochemical and mineralogical studies.
    Źródło:
    Geological Quarterly; 2013, 57, 3; 551--560
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    SHRIMP U-Pb zircon chronology of the Polish Western Outer Carpathians source areas
    Autorzy:
    Budzyń, B.
    Dunkley, D. J.
    Kusiak, M. A.
    Poprawa, P.
    Malata, T.
    Skiba, M.
    Paszkowski, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/191475.pdf
    Data publikacji:
    2011
    Wydawca:
    Polskie Towarzystwo Geologiczne
    Tematy:
    zircon
    U-Pb geochronology
    ion microprobe
    provenance
    Carpathians
    Opis:
    The Western Outer Carpathians flysch of Poland comprises clasts of crystalline rocks representing source areas that supplied sedimentary basins with clastic material. Zircon from quartz syenite and granite cobbles representing the Silesian Ridge, the currently unexposed source area located at the southern margin of the Silesian Basin, yielded uniform U-Pb dates of 604š6 Ma and 599š6 Ma. These are interpreted as the age of igneous crystallization. Similarly, zircon from a gneiss cobble derived from the northern source terrain gave 610š6 Ma date, which is interpreted as the age of crystallization of the granitic protolith to the gneiss. The Neoproterozoic magmatism is interpreted to have occurred at the Gondwana active margin.
    Źródło:
    Annales Societatis Geologorum Poloniae; 2011, 81, No 2; 161-171
    0208-9068
    Pojawia się w:
    Annales Societatis Geologorum Poloniae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Zircon U-Pb dating of igneous rocks in the Radzimowice and Wielisław Złotoryjski auriferous polymetallic deposits, Sudetes, SW Poland
    Autorzy:
    Mikulski, S. Z.
    Williams, I. S.
    Powiązania:
    https://bibliotekanauki.pl/articles/191720.pdf
    Data publikacji:
    2014
    Wydawca:
    Polskie Towarzystwo Geologiczne
    Tematy:
    zircon
    SHRIMP geochronology
    gold deposit
    porphyries
    Variscides
    Sudetes
    Opis:
    A rhyolite porphyry in the Radzimowice deposit at Bukowinka Hill has a SHRIMP zircon U-Pb age of 314.9 ± 3.1 Ma. This is consistent with previous zircon dating of a monzogranite and a rhyodacite (ca. 315 Ma) in the Żeleźniak sub-volcanic intrusion (ZI), considered to be the igneous rocks, representing the oldest magmatic pulses in the region. First-stage mesothermal auriferous sulphide mineralization in the deposit was connected to hydrothermal processes, associated with the rhyodacite intrusions. This was followed by tectonic activity and younger alkaline magmatism in a post-collisional geotectonic setting. The first-stage Au-bearing sulphide mineralization was cataclased and overprinted by younger epithermal base-metal sulphides with microscopic Au, associated with Bi-Te-Ag minerals. The younger magmatic pulses are represented by porphyritic andesites and lamprophyric dykes, which cut the ZI. Zircon from these dykes yielded ages of 312.8 ± 2.8 Ma for an andesite porphyry and 312.4 ± 4 Ma for a lamprophyre. All these magmatic pulses, evidenced in the Radzimowice deposit, are considered to be the oldest post-orogenic sub-volcanic magmatism cutting the basement of the intramontane basins in the Sudetes, on the NE margin of the Bohemian Massif. A rhyolite porphyry in the famous 'Organy' exposure at Wielisław Złotoryjski (WZ) on the SE margin of the North-Sudetic Basin is younger, 297.5 ± 2.8 Ma. Vein-type auriferous ore mineralization, hosted by Early Palaeozoic graphitic schists in intimate contact with rhyolite porphyry in WZ, is also correlated with this magmatism. The auriferous ore mineralization at Radzimowice and Wielisław Złotoryjski formed at different times, during different magmatic pulses and successive hydrothermal stages, despite several similarities in geologic setting and country- and host-rock compositions. There was a transition from a post-collisional to a within-plate setting over about 20 Ma in Late Carboniferous-Early Permian times, with the older Żeleźniak and Bukowinka sub-volcanic intrusions in the uplifted part of the Kaczawa Metamorphic Complex (ZI) and the younger Wielisław Złotoryjski sub-volcanic intrusion in the metamorphic basement of an intramontane basin.
    Źródło:
    Annales Societatis Geologorum Poloniae; 2014, 84, 3; 213-233
    0208-9068
    Pojawia się w:
    Annales Societatis Geologorum Poloniae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    40Ar-39 Ar ages of selected rocks and minerals from the Kraków-Lubliniec Fault Zone, and their relation to the Paleozoic structural evolution of the Malopolska and Brunovistulian terranes (S Poland)
    Autorzy:
    Nawrocki, J.
    Krzemiński, L.
    Pańczyk, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059087.pdf
    Data publikacji:
    2010
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    S Poland
    late Paleozoic
    palaeogeography
    Ar-Ar geochronology
    Opis:
    New 40Ar-39 Ar isotope ages of mafic and felsic rocks from the contact zone of the Malopolska and Brunovistulian terranes are presented and discussed. A 40Ar-39 Ar age estimation of detrital muscovite from a Lower Devonian "old red" type sandstone drilled on the Malopolska side of this zone was also done. Our studies reveal that three events of Paleozoic magmatic activity took place in the study area. The oldest, late Emsian episode is recorded by a diorite from the core part of an intrusion penetrated by the Sosnowiec IG 1 borehole. A younger, Visean event is documented by a diabase cored in the borehole WB-137. Diabases from Niedwiedzia Góra and from borehole PZ-10, and a rhyodacite from borehole 16-WB gave early Permian (Artinskian-early Sakmarian) ages. The youngest, middle Sakmarian age was obtained for a diabase forming the external parts of the Sosnowiec IG 1 polycyclic intrusion. A diorite penetrated by the Sosnowiec IG 1 borehole was emplaced during the late Emsian extension that preceded the Lochkovian-Pragian? transpression related to the final docking and amalgamation of the Brunovistulian Terrane.
    Źródło:
    Geological Quarterly; 2010, 54, 3; 289-300
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Late Svecofennian sedimentary basins in the crystalline basement of NE Poland and adjacent area of Lithuania: ages, major sources of detritus, and correlations
    Autorzy:
    Krzeminska, E.
    Wiszniewska, J.
    Skridlaite, G.
    Williams, I. S.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059225.pdf
    Data publikacji:
    2009
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Fennoscandia
    Sarmatia
    Greenland
    Svecofennian basin
    detrital zircon
    geochronology
    Opis:
    The Pre cam brian base ment of Lith u a nia and NE Po land, much of which is metasedimentary paragneiss, can be ac cessed only by cores from deep bore holes. Ion microprobe dat ing of de tri tal zir cons from sam ples of these meta sedi ments and the geo chem i cal sig na tures of the rocks pro vide new in sights into their age and prov e nance. De tri tal zir cons from meta sedi ments from Jastrzebna and Monki have Pb iso to pic ages in the ranges 3.14–1.83 and 3.53–1.82 Ga, re spec tively. Sim i lar re sults have been ob tained from the Lith u a nian Lazdijai and Bliudziai paragneisses. About 30% of the ana lysed Pol ish de tri tal zir con cores are of Late Archaean age (2.90–2.60 Ga) and about 70% are Palaeoproterozoic (2.10–1.90 Ga), sim i lar to the age dis tri bu tions of de tri tal zir con from Svecofennian meta sedi ments ex posed in Cen tral Swe den and South ern Fin land. The youn gest de tri tal zir con sub-groups in di cate max i mum de po si tion ages of about 1.86 Ga, sim i lar to the ages of ex posed Svecofennian sed i men tary bas ins. Pos si ble source rocks of com pa ra ble ages and af fin i ties can be found within Fennoscandia, Green land and Sarmatia.
    Źródło:
    Geological Quarterly; 2009, 53, 3; 255-272
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A reappraisal of K-Ar and new U-Pb age data for felsic rocks in the vicinity of the Kraków-Lubliniec Fault Zone (southern Poland)
    Autorzy:
    Jarmołowicz-Szulc, Katarzyna
    Powiązania:
    https://bibliotekanauki.pl/articles/2060264.pdf
    Data publikacji:
    2020
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    magmatic rocks
    zircon
    geochronology
    Kraków-Lubliniec Fault Zone
    Opis:
    New U-Pb zircon SHRIMP determinations from magmatic silicic rocks adjacent to the NE part of the Upper Silesia Coal Basin (USB) are provided and compared with earlier data obtained by K-Ar dating. The zircon samples studied came from the same boreholes and depth intervals previously sampled for K-Ar datings. Recalculations of the earlier K-Ar values for biotites yielded isochron ages in the range of 297-309 Ma. The zircon U-Pb SHRIMP values gave more precise ages between 300.1 ±1.2 Ma and 292.6 ±1.3 Ma (1б) consistent with U-Pb and Re-Os determinations. In two cases, the recalculated results of K-Ar dates were nearly identical with those obtained from the SHRIMP isotopic analyses. In this context, the granitoids and porphyries of the USB area, once assigned to the Carboniferous-Permian based on the older K-Ar studies, actually are of the same age as other felsic igneous rocks from the vicinity of the Kraków-Lubliniec Fault Zone, with a higher dating precision, however. The new data underline the importance of Late Carboniferous-Early Permian felsic magmatism at the SW margin of the Trans-European Suture Zone in southern Poland. In the zircon populations dated, besides the dominant Late Paleozoic ages, there are some inherited zircon cores, likely remnant detrital grains from a sediment component in the source rocks, that reveal much older ages which range from ~2051 to 569 Ma.
    Źródło:
    Geological Quarterly; 2020, 64, 3; 754--765
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Karst processes and time
    Procesy krasowe a czas
    Autorzy:
    Bosak, Pavel
    Powiązania:
    https://bibliotekanauki.pl/articles/94511.pdf
    Data publikacji:
    2008
    Wydawca:
    Uniwersytet im. Adama Mickiewicza w Poznaniu
    Tematy:
    kras
    speleogeneza
    geochronologia
    niezgodności
    karst
    speleogenesis
    geochronology
    unconformities
    Opis:
    Karst evolution depends particularly on the time available for process evolution and on the geographical and geological conditions of the exposure of the rock. The longer the time, the higher the hydraulic gradient and the larger the amount of solvent water entering the karst system, the more evolved is the karst. In general, stratigraphic discontinuities directly influence the intensity and extent of karstification. Unconformities influence the stratigraphy of the karst through the time-span that is available for subaerial processes. The end of karstification can also be viewed from various perspectives. The definite end occurs at the moment when the host rock, together with its karst phenomena, has completely been eroded/denuded. Karst forms of individual evolution stages (cycles) can also be destroyed by erosion, denudation and abrasion without the necessity of the destruction of the whole succession of karst rocks. Temporary and/or final interruption of the karstification process can be caused by the “fossilisation” of the existing karst phenomena due to loss of hydrological activity. The shorter the time available for karstification, the greater is the likelihood that karst phenomena are pre-served in the stratigraphic record. While products of short-lived karstification on shallow carbonate platforms can be preserved by deposition during a immediately succeeding sea-level rise, products of more pronounced karstification can be destroyed by various geomorphological processes. The longer the duration of subaerial exposure, the more complex these geomorphological agents are.
    Rozwój procesów krasowych jest funkcją czasu oraz geograficznych i geologicznych warunków odsłonięcia skał. Im dłuższy czas ekspozycji skał na czynniki meteorologiczne, większy gradient hydrauliczny, większa ilość wody w układzie krasowym, tym bardziej zaawansowana jest ewolucja krasu. Intensywność i zasięg krasowienia zależą też od niezgodności stratygraficznych, czyli przerw w sedymentacji. Zakończenie rozwoju procesów krasowych rozpatrywać można w różnych kategoriach. Za definitywny koniec należy uznać czas, gdy skały podlegające krasowieniu ulegną całkowitej denudacji/erozji. O wiele częściej bywa, że zniszczeniu ulegają tylko formy krasowe, natomiast niżej położone skały systemu krasowego pozostają zachowane. Okresowe lub całkowite przerwanie procesów krasowych może być spowodowane przez fosylizację systemu krasowego, która zachodzi w efekcie zaniku aktywności hydrologicznej. Taka fosylizacja może być spowodowana przez metamorfizm, transgresję morską, pogrzebanie osadami kontynentalnymi lub skałami wulkanicznymi, w wyniku np. ruchów tektonicznych, zmiany klimatu, itp. Im krótszy jest czas krasowienia, tym większe jest prawdopodobieństwo zachowania śladów procesów krasowych. I tak, produkty krótkookresowej karstyfikacji na płytkich, okresowo wynurzanych platformach węglanowych mogą ulegać łatwemu zachowaniu poprzez pogrzebanie osadami deponowanymi podczas podniesienia poziomu morza. Natomiast efekty długotrwałego krasowienia bywają często niszczone przez późniejsze degradacyjne procesy geomorfologiczne. Charakter tych ostatnich jest tym bardziej skomplikowany, im dłużej trwa subaeralna ekspozycja skrasowiałych skał.
    Źródło:
    Geologos; 2008, 14, 1; 19-36
    1426-8981
    2080-6574
    Pojawia się w:
    Geologos
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Tournaisian 40Ar/39Ar age for alkaline basalts from the Lublin Basin (SE Poland)
    Autorzy:
    Pańczyk, M.
    Nawrocki, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059639.pdf
    Data publikacji:
    2015
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    alkaline basaltic rocks
    Ar-Ar geochronology
    Carboniferous
    Lublin Basin
    Opis:
    The main aim of this study is to define precisely the age of the alkaline basalts occurring within the lowermost part of Carboniferous succession in the northeastern part of LublinBasin(drill core Parczew IG-7 and IG-9; SE Poland). The new, whole-rocks 40Ar/39Ar data constrain the age of volcanic activity and emplacement of alkaline basalts to the Late Tournaisian (348 ± 0.8 Ma) with possible prolongation to the Middle Visean (338.5 ± 0.7 Ma). The younger age is however of evidently poorer quality than the older one. The new data caused to correlate the volcanic processes occurring within the Lublin Basin with alkaline intrusions drilled inNE Poland inside the Paleozoic cover of the East European Platform. They also correspond to the volcanoclastic levels defined in different parts of the Trans European Suture Zone in Poland.
    Źródło:
    Geological Quarterly; 2015, 59, 3; 473--478
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Badania geochronologiczne skał podłoża krystalicznego na obszarze północno-wschodniej Polski : przegląd i podsumowanie
    Geochronological studies on the crystalline bedrock from NE Poland : an overview and summary
    Autorzy:
    Jarmołowicz-Szulc, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/2075683.pdf
    Data publikacji:
    2017
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    podłoże krystaliczne
    NE Poland
    odwierty
    geochronologia
    crystalline basement
    boreholes
    geochronology
    Opis:
    Since the mid-1950s, when Jerzy Znosko started his huge contribution to the recognition of the crystalline basement of NE Poland, many different studies have followed the planned and implemented drilling projects. The drillings, conducted in the first decade under the leadership of Professor Znosko and under his description of the results, were further worked out by other researchers. Studies concerned petrological, geochemical and miner- alogical aspects. In that fan of methods applied, geochronological data started to be introduced to the bibliography of the area in the early 1960s. Geochronological methods that time mean mostly K-Ar and some Rb-Sr values. These materials are gathered in the paper aiming at its presentation, re-valuation and interpretation in terms of the significance of such data for further development of knowledge.
    Źródło:
    Przegląd Geologiczny; 2017, 65, 12; 1536--1539
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    How to resolve Pleistocene stratigraphic problems by different methods? A case study from eastern Poland
    Autorzy:
    Terpiłowski, S.
    Zieliński, T.
    Kusiak, J.
    Pidek, I.A.
    Czubla, P.
    Hrynowiecka, A.
    Godlewska, A.
    Zieliński, P.
    Małek, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059725.pdf
    Data publikacji:
    2014
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    chronostratigraphy
    geochronology
    interglacial meandering river
    Pleistocene
    Mazovian/Holsteinian
    Eastern Poland
    Opis:
    Different methods have been used to determine the stratigraphic position of Pleistocene alluvial deposits, particularly fluvial interglacial deposits. Near-surface deposits of a meandering river, developed in point-bar and oxbow lake facies, in the Samica River valley (near Łuków, eastern Poland) have been investigated. The fossil valley is incised into the till plain and the outwash. The fluvial succession is locally overlain by solifluction deposits. All the deposits underwent sedimentological analysis. The petrographic composition of basal till occurring in the vicinity of a fossil valley was determined with the method of indicator erratics. Fluvial deposits were examined by pollen analysis and plant macrofossil analysis of oxbow lake facies. Absolute dating methods were applied to the deposits (thermoluminescence methods: TL and additionally IRSL). Lithological differences between fluvial and the surrounding glaciofluvial deposits were identified and their lithostratigraphic position assigned. Petrographic analysis of till and palaeobotanical analyses of oxbow lake facies gave compatible results. Fluvial deposits were formed after the Sanian 2/Elsterian Glaciation, during the Mazovian/Holsteinian Interglacial. Luminescence dating of the fluvial deposits by the TLMAX method yielded the most relevant results (412-445 ka), which indicate that these deposits were formed during the end of the MIS 12 and beginning of the MIS 11 stage.
    Źródło:
    Geological Quarterly; 2014, 58, 2; 235--250
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Variscan granitoid plutonism in the Strzelin Massif (SW Poland) : petrology and age of the composite Strzelin granite intrusion
    Autorzy:
    Oberc-Dziedzic, T.
    Kryza, R.
    Pin, C.
    Madej, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059728.pdf
    Data publikacji:
    2013
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    zircon SHRIMP geochronology
    composite granitoid plutons
    Variscan granitoids
    Strzelin Massif
    Opis:
    Petrological data and recently published U/Pb zircon SHRIMP ages reveal a protracted Variscan magmatic evolution in the Strzelin Massif (SW Poland), with three main stages of granitoid plutonism: 1 – tonalitic I, 2 – granodioritic and 3 – tonalitic II/granitic. The granitoids of the second and third stages form the Strzelin intrusion that is composed of three varieties: medium-grained biotite granite, fine-grained biotite granite and fine-grained biotite-muscovite granite. New SHRIMP data show that the medium-grained and fine-grained biotite granites comprise different zircon populations that reflect complex and prolonged plutonic processes. Two distinct magmatic events seem to be represented by well-defined zircon populations with apparent 206Pb/238U ages of 303 ± 2 Ma in the medium-grained biotite granite, and 283 ± 8 Ma in the fine-grained biotite granite. These dates, however, do not necessarily reflect the true magmatic ages, possibly being “rejuvenated” by radiogenic lead loss in zircons (impossible to resolve based on routine SHRIMP data). Based on field evidence, the third variety, the biotite-muscovite granite, postdates both types of biotite granites. The petrographic and geochemical features, including Nd isotope signature, along with various zircon inheritance patterns and ages, suggest that the parental magmas of the three granites originated from different crustal sources and were emplaced during three successive magmatic pulses.
    Źródło:
    Geological Quarterly; 2013, 57, 2; 269--288
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Stability of monazite and disturbance of the Th-U-Pb system under experimental conditions of 250–350 °C and 200–400 MPa
    Autorzy:
    Budzyń, B.
    Konečný, P.
    Kozub-Budzyń, G. A.
    Powiązania:
    https://bibliotekanauki.pl/articles/191272.pdf
    Data publikacji:
    2015
    Wydawca:
    Polskie Towarzystwo Geologiczne
    Tematy:
    monazite
    apatite
    steacyite
    rare earth elements (REE)
    geochronology
    experimental petrology
    Opis:
    This experimental study provides important data filling the gap in our knowledge on monazite stability under conditions of fluid-mediated low-temperature metamorphic alteration and post-magmatic hydrothermal alterations. The stability of monazite and maintenance of original Th-U-total Pb ages were tested experimentally under P-T conditions of 250–350 °C and 200–400 MPa over 20–40 days. The starting materials included the Burnet monazite + K-feldspar ± albite ± labradorite + muscovite + biotite + SiO2 + CaF2 and 2M Ca(OH)2 or Na2Si2O5 + H2O fluid. In the runs with 2M Ca(OH)2, monazite was unaltered. REE-enriched apatite formed at 350 °C and 400 MPa. The presence of the Na2Si2O5 + H2O fluid promoted the strong alteration of monazite, the formation of secondary REE-enriched apatite to fluorcalciobritholite, and the formation of REE-rich steacyite. Monazite alteration included the newly developed porosity, patchy zoning, and partial replacement by REE-rich steacyite. The unaltered domains of monazite maintained the composition of the Burnet monazite and its age of (or close to) ca. 1072 Ma, while the altered domains showed random dates in the intervals of 375–771 Ma (250 °C, 200 MPa run), 82–253 Ma (350 °C, 200 MPa), and 95–635 Ma (350 °C, 400 MPa). The compositional alteration and disturbance of the Th-U-Pb system resulted from fluid-mediated coupled dissolution-reprecipitation. In nature, such age disturbance in monazite can be attributed to post-magmatic alteration in granitic rocks or to metasomatic alteration during metamorphism. Recognition of potentially altered domains (dark patches in high-contrast BSE-imaging, developed porosity or inclusions of secondary minerals) is crucial to the application of Th-U-Pb geochronology.
    Źródło:
    Annales Societatis Geologorum Poloniae; 2015, 85, 2; 405-425
    0208-9068
    Pojawia się w:
    Annales Societatis Geologorum Poloniae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Strontium isotope dating of bivalve faunas from the Upper Miocene Cacela Formation, eastern Algarve, Portugal: evidence from Messinian bivalve fauna
    Autorzy:
    Studencka, B.
    Zieliński, G.
    Powiązania:
    https://bibliotekanauki.pl/articles/2060317.pdf
    Data publikacji:
    2013
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Bivalvia
    Cacela Formation
    87Sr/86Sr geochronology
    Messinian
    Portugal
    Opis:
    The study is focused on the determination of the geological age of bivalve fauna recovered from four fossiliferous sequences in the Cacela Formation of Algarve, southern Portugal, by means of the strontium isotope stratigraphy. Forty two analyses of bivalve samples from Barroquinha, Cabanas, the Cacela River and Lacem were performed. The estimated age based on the 87Sr/86Sr ratios in bivalve shell samples from the Cacela River (a reference section for the Cacela Formation) is 7.6 ± 0.4 Ma and is consistent with a late Tortonian age suggested by micropalaeontological data (calcareous nannofossils and planktonic foraminifers). Moreover, strontium isotopic data record that the oldest age of the bivalves of the Cacela Formation (Lacem site) is at least 8.9 ± 0.4 Ma whilst the age of about 7.0 ± 0.5 Ma can be inferred for bivalves from Barroquinha. An intriguing new datum comes, however, from the bivalve strontium isotopic data of the Cabanas section which records the estimated age of about 6.7 ± 0.4 Ma and, therefore, an early Messinian age. This is the first report of the early Messinian marine bivalve fauna in Portugal. Sixty one bivalve species have been recovered in the Messinian of Cabanas. Four of them: Pseudopythina macandrewi (P. Fischer), Coripia corbis (Philippi), Glossus (Glossus) humanus (Linnaeus) and Cyathodonta dollfusi (Cossmann et Peyrot) have previously not been reported from the Miocene of southern Portugal.
    Źródło:
    Geological Quarterly; 2013, 57, 4; 665--686
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Geological development of the Nemunas River Delta and adjacent areas, West Lithuania
    Autorzy:
    Bitinas, A.
    Damusyte, A.
    Stančikaite, M.
    Aleksa, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059891.pdf
    Data publikacji:
    2002
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Lithuania
    Lithuanian Maritime region
    Nemunas Delta
    Late Glacial
    Holocene
    geochronology
    palaeogeography
    Opis:
    Geological mapping at a scale of 1:50 000 of the Lithuanian Maritime region has recently been focused on the delta of the Nemunas River and its surroundings. Pollen, diatom and mollusc analyses, lithological investigations, and radiocarbon and optically stimulated luminescence dates have enabled stratigraphic correlation of the Late Glacial and Holocene deposits which make up this delta. Palaeogeographical reconstructions of the southern part of the Lithuanian Maritime region during the maximum extent of the Baltic Ice Lake (~12 000-11 200 years BP), the Ancylus Lake (~8 700-8 500 years BP), the Litorina Sea (~6 100 years BP) and the Post-Litorina Sea (~4 000 years BP) have been made. A geological and geomorphological model of the Nemunas River Delta and its adjacent areas has been constructed. Our results suggest that that part of Nemunas River Delta in Lithuania is very young, having formed during the last 1 000-1 100 years.
    Źródło:
    Geological Quarterly; 2002, 46, 4; 375-390
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Age constraints on the Pre-Variscan and Variscan thermal events in the Kamieniec Ząbkowicki Metamorphic belt (the Fore-Sudetic Block, SW Poland)
    Autorzy:
    Jastrzębski, Mirosław
    Żelaźniewicz, Andrzej
    Budzyń, Bartosz
    Sláma, Jiří
    Konečny, Patrik
    Powiązania:
    https://bibliotekanauki.pl/articles/1836361.pdf
    Data publikacji:
    2020
    Wydawca:
    Polskie Towarzystwo Geologiczne
    Tematy:
    U-Pb geochronology
    LA-ICP-MS dating
    U-Th-total Pb geochronology
    EPMA dating
    microplates of the Bohemian Massif
    Kamieniec Ząbkowicki Metamorphic Belt
    Variscan metamorphism
    Opis:
    The Kamieniec Ząbkowicki Metamorphic Belt (KZMB) is a narrow zone of mainly mica schists, subordinate acid metavolcanics and scarce eclogites, sandwiched between Brunovistulia and the northern tip of the Teplá-Barrandia microplates. Locally occurring high-pressure relics indicate subduction of the metasedimentary succession of the KZMB, the origin and provenance of which remain unclear. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) investigations of detrital zircons show that the metapelites represent an Ediacaran-Cambrian sedimentary basin, with a maximum depositional age of 561±9 Ma. This basin was filled with detritus from a source or sources, composed of rocks containing zircons that are mainly Cryogenian-Ediacaran and Palaeoproterozoic in age. No younger component was found in the zircon population studied. The isotopic U-Pb LA-ICP-MS and chemical U-Th-total Pb electron probe microanalysis (EPMA) monazite geochronology data indicate an important regional tectono-metamorphic event at ca. 330 Ma. Though these data do not permit determination of the peak pressure from the peak temperature stages, the event was part of a complex collision of the Saxothuringian plate with Brunovistulia.
    Źródło:
    Annales Societatis Geologorum Poloniae; 2020, 90, 1; 27-49
    0208-9068
    Pojawia się w:
    Annales Societatis Geologorum Poloniae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Possible pitfalls in the procedure for paleobiodiversity-dynamics analysis
    Pułapki analizy paleo-bioróżnorodności
    Autorzy:
    Ruban, Dmitry A.
    Loon, A. J. (Tom)
    Powiązania:
    https://bibliotekanauki.pl/articles/94348.pdf
    Data publikacji:
    2008
    Wydawca:
    Uniwersytet im. Adama Mickiewicza w Poznaniu
    Tematy:
    biodiversity
    taxonomy
    biostratigraphy
    geochronology
    Lazarus taxa
    bioróżnorodność
    taksonomia
    biostratygrafia
    geochronologia
    taksony Łazarza
    Opis:
    The changes in the diversity of specific taxa during certain parts of the geological past (paleobiodiversity dynamics) can, in principle, be established by counting the number of the fossil taxa present (worldwide or in a specific study area) in rocks dated for the time interval under study. Numerous obstacles are present, however, for instance in the form of lacking field data, disappeared collections, ambiguous identifications, temporary ‘disappearence’ of taxa, and dating problems. One major problem is the fact that, particularly in regional studies in some countries, a local, regional or national chronostratigraphic terminology is used rather than the chronostratigraphy recommended by the International Stratigraphic Commision of the International Union of Geological Sciences. This hampers international correlation and makes precise global paleodiversity-dynamics analyses extremely difficult. A reliable insight into the true paleodiversity dynamics requires not only that the various problems are recognized, but also that their consequences are eliminated or, if this is impossible, minimized. This is particularly important if the effects of mass extinctions on fauna and flora are investigated. Each analysis of paleobiodiversity-dynamics analysis of phenomena related to mass extinctions should therefore try to quantify the impact that missing data or inaccuracies of any kind may have on the final results; such an analysis should, in addition, try to find a solution for the major problems, so as to avoid significant inaccuracies of the calculated values. Large electronic databases can help, since about a decade, to diminish possible errors in diversity estimates. Paleobiodiversity should preferably be expressed in the form of values with a certain band with, indicating the inaccuracy, rather than in the form of exact values.
    Zmiany w zróżnicowaniu gatunków w pewnych przedziałach czasu przeszłości geologicznej (dynamika paleo-bioróżnorodności) są z zasady ustalane poprzez zliczanie liczby taksonów skamieniałości (na świecie lub na wybranym obszarze) w skałach datowanych na badany interwał czasowy. Tym niemniej procedura ta napotyka wiele przeszkód, np. w postaci braku danych z jakiegoś obszaru, zagubionych kolekcji, niejednoznacznych identyfikacji, czasowego „zaniku” taksonów czy problemów datowania. Jednym z głównych problemów, zwłaszcza w badaniach regionalnych w niektórych krajach, jest stosowanie lokalnej, regionalnej lub krajowej terminologii chronostratygraficznej, a nie chronostratygrafii rekomendowanej przez Międzynarodową Komisję Stratygraficzną przy Międzynarodowej Unii Nauk Geologicznych. Utrudnia to międzynarodowe korelacje i czyni niezwykle trudnym przeprowadzenie precyzyjnej globalnej analizy dynamiki paleo-bioróżnorodności. Wiarygodny wgląd w prawdziwą dynamikę paleo-bioróżnorodności wymaga nie tylko rozpoznania różnych problemów, ale również wyeliminowania ich konsekwencji, a gdy to niemożliwe, zminimalizowania ich. Jest to szczególnie ważne w przypadku, gdy badane są następstwa masowego wymierania fauny i flory. Dlatego każda analiza dynamiki paleo-bioróżnorodności zjawisk związanych z masowym wymieraniem powinna zawierać próbę ilościowego oszacowania wpływu, jakie brakujące dane lub niedokładności jakiegokolwiek rodzaju mogą wywierać na końcowe wnioski. Taka analiza powinna próbować znaleźć rozwiązanie dla głównych problemów, ażeby uniknąć znaczących niedokładności w obliczonych wartościach. Duże elektroniczne bazy danych, dostępne od około 10 lat, mogą pomóc w zmniejszeniu możliwych błędów przy szacowaniu różnorodności. Najlepiej, gdyby paleo-bioróżnorodność była wyrażana w formie wartości w pewnym zakresie, wskazującym na niedokładność, a nie w formie precyzyjnej wartości.
    Źródło:
    Geologos; 2008, 14, 1; 37-50
    1426-8981
    2080-6574
    Pojawia się w:
    Geologos
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Chronostratygrafia późnoczwartorzędowych klastycznych osadów jaskiniowych w Polsce w XIX i w XXI wieku - ile się zmieniło?
    Chronostratigraphy of Late Quaternary clastic cave sediments in Poland in 19th and 21st centuries - what has changed?
    Autorzy:
    Krajcarz, M. T.
    Powiązania:
    https://bibliotekanauki.pl/articles/2074926.pdf
    Data publikacji:
    2012
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Edouard Lartet
    stratygrafia
    geochronologia
    czwartorzęd
    osady jaskiniowe
    stratigraphy
    geochronology
    Quaternary
    cave filling
    Opis:
    In 21st century the chronostratigraphy of cave sediments is built on the basis of modern methods: sedimentological analysis, statistical analysis of palaeozoological data, radiometric and luminescence dating and many others. For the time of last 50 000 years the four geochronological units (or appropriate chronostratigraphic units) are usually proposed in Poland in the researches of cave sediments. They are: Interpleniglacial, Upper/Younger Pleniglacial, Late Glacial and Holocene. That scheme has over 150 years of evolution, and its origin was tied with biostratigraphical scheme built by Edouard Lartet in a middle of 19th century. Lartet's stratigraphy for the same period was also made of four units: Cave Bear Epoch, Mammoth and Wooly Rhinoceros Epoch, Reindeer Epoch and Auroch Epoch. Although basing on different methods and using different terminology, the two schemes – from the 19th and from 21st centuries – are similar and correlatabl
    Źródło:
    Przegląd Geologiczny; 2012, 60, 2; 85-88
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Tadeusz Depciuch : pionier badań geochronologicznych w Polsce
    Tadeusz Depciuch : pioneer of geochronological studies in Poland
    Autorzy:
    Miecznik, J. B.
    Powiązania:
    https://bibliotekanauki.pl/articles/2075103.pdf
    Data publikacji:
    2014
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    K-Ar geochronology
    Sudetes
    NE Poland
    uranium deposits
    geochronologia
    Sudety
    Polska
    złoża uranu
    Opis:
    Dr Tadeusz Depciuch (1928–2007), geochemist, mineralogist and economic geologist, longtime employee of the Polish Geological Institute in Warsaw, as the first scientist in Poland who conducted a systematic study on isotopic age of crystalline rocks. In 1966, after preliminary age determinations by Dr Jerzy Borucki, he undertook research of crystalline rocks of the Lower Silesian Block, mainly granites, and subsequently of rocks of the basement of the Polish part of the East European Precambrian Platform penetrated in the 1960s and 1970s, as well as igneous rocks of its cover. He used the K-Ar method, applying its volumetric variety on own-designed equipment. Age determinations allowed identifying the magmatic and metamorphic stages of the development of the crystalline basement evolution, and establishing the stratigraphy. They also played an important role in the research on Variscan plutonism in Lower Silesia. Tadeusz Depciuch participated in prospecting for uranium deposits in the Sudetes, using geochemical methods, and studied the origin of some deposits. In 1974–1984, he worked in Africa (Benin) as a UN expert in the field of geochemistry and economic geology.
    Źródło:
    Przegląd Geologiczny; 2014, 62, 10/1; 503--509
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Detrital zircon U-Pb geochronology of a metasomatic calc-silicate in the Tsäkkok Lens, Scandinavian Caledonides
    Autorzy:
    Barnes, Cristopher J.
    Majka, Jarosław
    Bukała, Michał
    Nääs, Erika
    Rousku, Sabine
    Powiązania:
    https://bibliotekanauki.pl/articles/1841761.pdf
    Data publikacji:
    2021
    Wydawca:
    Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
    Tematy:
    Scandinavian Caledonides
    Seve Nappe Complex
    Tsäkkok Lens
    metasomatism
    detrital zircon U-Pb geochronology
    Opis:
    The Tsäkkok Lens of the Seve Nappe Complex in the Scandinavian Caledonides comprises eclogite bodies hosted within metasedimentary rocks. These rocks are thought to be derived from the outermost margin of Baltica along the periphery of the Iapetus Ocean, but detrital records from the sedimentary rocks are lacking. Many metasedimentary outcrops within the lens expose both well-foliated metapelitic rocks and massive calc-silicates. The contacts between these two lithologies are irregular and are observed to trend at all angles to the high-pressure foliation in the metapelites. Where folding is present in the metapelites, the calc-silicate rocks are also locally folded. These relationships suggest metasomatism of the metapelites during the Caledonian orogenesis. Zircon U-Pb geochronology was conducted on sixty-one zircon grains from a calc-silicate sample to investigate if they recorded the metasomatic event and to assess the detrital zircon populations. Zircon grains predominantly show oscillatory zoning, sometimes with thin, homogeneous rims that have embayed contacts with the oscillatory-zoned cores. The zircon cores yielded prominent early Stenian, Calymmian, and Statherian populations with a subordinate number of Tonian grains. The zircon rims exhibit dissolution-reprecipitation of the cores or new growth and provide ages that span similar time frames, indicating overprinting of successive tectonic events. Altogether, the zircon record of the calc-silicate suggests that the Tsäkkok Lens may be correlated to Neoproterozoic basins that are preserved in allochthonous positions within the northern extents of the Caledonian Orogen.
    Źródło:
    Geology, Geophysics and Environment; 2021, 47, 1; 21-31
    2299-8004
    2353-0790
    Pojawia się w:
    Geology, Geophysics and Environment
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Wiek izotopowy Re-Os siarczkowej mineralizacji Cu-Ag oraz jej charakterystyka mineralogiczna i geochemiczna z obszaru złożowego Lubin–Polkowice (SW Polska)
    Re-Os isotopic age of the Cu-Ag sulphide ore and its mineralogical and geochemical characteristic from the Lubin–Polkowice mining area (SW Poland)
    Autorzy:
    Mikulski, S. Z.
    Stein, H.J.
    Powiązania:
    https://bibliotekanauki.pl/articles/2061706.pdf
    Data publikacji:
    2017
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    geochronologia Re-Os
    bornit
    chalkopiryt
    łupek miedzionośny
    Re-Os geochronology
    bornite
    chalcopyrite
    Kupferschiefer
    Opis:
    W artykule przedstawiono wyniki badań izotopowych Re-Os oraz charakterystykę mineralogiczno-geochemiczną mineralizacji bornitowej i chalkopirytowej występujących w postaci żyłkowo-impregnacyjnej w czarnych łupkach miedzionośnych formacji cechsztyńskiej z obszaru złożowego Lubin i Polkowice. Zbadane próbki reprezentują rudę siarczkową Cu-Ag o zawartościach miedzi od ok. 2,5 do 14,2% ze zróżnicowaną domieszką Ag (40–900 ppm) oraz zawartością substancji organicznej na poziomie ok. 6%. Wartości stosunków chemicznych, takich jak: Co/Ni = 0,1–0,7, V/Cr = 4–17 czy Fe2O3/Corg. = 0,6–1,9 i in., są w zakresach typowych dla czarnych łupków miedzionośnych z formacji cechsztyńskiej. Oprócz siarczków miedzi, które zawierają stałą domieszkę Ag (np. chalkozyn – 0,44–5,03% wag., bornit – 0,33–0,77% wag., chalkopiryt 0,09–0,20% wag.), obecne są również podrzędnie galena, sfaleryt, minerały Ag oraz powszechnie piryt framboidalny. W zbadanych izotopowo próbkach bornitu i chalkopirytu, występujących w postaci żyłek zgodnych z laminacją w łupku, zmierzone zawartości renu wahają się od 5,7 do 12 ppb, a całkowita zawartość osmu – od 27 do 50 ppt. W siarczkach tych jest wysoki udział zwykłego osmu. Stosunki izotopowe: 187Re/188Os są bardzo wysokie, w zakresie od 2269 do 2942, a 187Os/188Os – od ok. 9,8 do ok. 12,4. Obliczony dla tych wartości wiek modelowy Re-Os krystalizacji siarczków miedzi mieści się w zakresie od 268 do 256 mln lat oraz dla jednej próbki żyłki chalkopirytowej – 217 ±2 mln lat. Biorąc pod uwagę wartości stosunków izotopowych 187Re/188Os, możliwe było wyliczenie czteropunktowej izochrony wieku modelowego Re-Os (wiek modelowy 1), który wyniósł 212 ±7 mln lat przy założeniu stosunku inicjalnego 187Os/188Os = 2,13 ±0,31 (MSWD = 1,3; n = 4). Uzyskany wiek modelowy 1 wskazuje na krystalizację bornitu i chalkopirytu, występujących w czarnych łupkach cechsztyńskich w postaci żyłek równoległych do laminacji, w późnym triasie (noryku).
    In the paper we present the results of Re-Os isotopic studies as well as the mineralogical and geochemical characteristic of bornite veinlets with chalcopyrite ± chalcocite margins and chalcopyrite veinlets that are parallel to sub-parallel to bedding in the Kupferschiefer from the underground workings of the Lubin and Polkowice mines in SW Poland. Kupferschiefer samples are of grade from 2.5 to 14.2% Cu and with silver admixtures from 40 to 900 ppm and organic matter contents ca. 6%. The ratios of Co/Ni = 0.1–0.7, V/Cr = 4–17 and Fe2O3/Corg = 0.6–1.9 are in the range of values typical for the Kupferschiefer. Besides, copper sulphides, which commonly contain silver admixtures (e.g., chalcocite – 0.44–5.03 wt.%, bornite – 0.33–0.77 wt.%, chalcopyrite 0.09–0.20 wt.%) are associated with minor galena, sphalerite, Ag-minerals and common pyrite framboids. In the isotopically analysed bornite and chalcopyrite samples Re concentrations ranging from 5.7 to 12 ppb, and total Os concentrations ranging from 27 to 52 ppt. Significant common Os is present in all of the analysed sulphides. The isotopic ratios of 187Re/188Os are very high (range: 2269–2942), and of 187Os/188Os from 9.8 to ca. 12.4. Re-Os model ages calculated for these isotopic ratios are in the range from 256 to 268 Ma and for one of the chalcopyrite veinlet was 217 ±2 Ma. Taking into the account the values of the isotopic ratios of 187Re/188Os, it was possible to construct the Re-Os isochrone age for A Model 1regression based on four different samples. They yields age of 212 ±7 Ma, with an initial 187Os/188Os ratio of 2.13 ±0.31 (MSWD = 1.3). Re-Os isochrone age indicates for bornite and chalcopyrite crystallization event of the Ag-bearing Cu sulphide mineralization within the Kupferschiefer in the Late Triassic (Norian), ca. 212 ±7 Ma.
    Źródło:
    Biuletyn Państwowego Instytutu Geologicznego; 2017, 468; 79--96
    0867-6143
    Pojawia się w:
    Biuletyn Państwowego Instytutu Geologicznego
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    New data on the age of the sedimentary infill of the Orava-Nowy Targ Basin : a case study of the Bystry Stream succession (Middle/Upper Miocene, Western Carpathians)
    Autorzy:
    Wysocka, A.
    Łoziński, M.
    Śmigielski, M.
    Czarniecka, U.
    Bojanowski, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/2059754.pdf
    Data publikacji:
    2018
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    tuffite
    terrestrial facies
    U-Pb geochronology
    strike-slip faulting
    Miocene
    Orava-Nowy Targ Basin
    Opis:
    The Neogene sedimentary succession of the Orava-Nowy Targ Basin directly overlies the Central Carpathian Paleogene Basin deposits, the Magura Unit, and the Pieniny Klippen Belt. It provides an excellent geological record that postdates the main Mesoalpine structural and geomorphological processes in the Western Carpathians. Sedimentological, petrographical and geochronological investigations have allowed forthe re-examination of pyroclastic material, zircon dating, and a discussion on the relation of the Orava-Nowy Targ Basin to the exhumation of the Tatra Massif. The Bystry Stream succession is composed of NNW-inclined freshwater siltstones, sandstones and conglomerates. A few small, sometimes discontinuous, light grey intercalations of pyroclastic deposits and a single 1-2 m thick tuffite layer occur in the upper part of the succession. The tuffite contains an admixture of organic matter and siliciclastic grains (e.g., mica), suggesting that the volcanic ash fall was accompanied by normal deposition from weak currents. Sedimentation of deposits of the Bystry Stream succession took place in terrestrial settings, predominantly on floodplains and in rivers, in the vicinity of a hilly area supplying the basin with eroded material. The age of the tuffite layer from the Bystry Stream succession was determined at 11.87 +0.12/-0.24 Ma. The source of volcanogenic material in the tuffite was probably volcanic activity in the Inner Carpathians-Pannonian region, where effusive and volcanoclastic sillca-rich rocks were being produced by extrusive and explosive activity ~12 Ma. Obtained result connects the development of the Orava-Nowy Targ Basin at ~12 Ma with the late stage of the main episode of the Tatra Massif exhumation between ~22-10 Ma.
    Źródło:
    Geological Quarterly; 2018, 62, 2; 327--343
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Wczesnokarboński wiek intruzji platformowych w podłożu krystalicznym NE Polski
    Early Carboniferous age of the cratonic intrusions in the crystalline basement of NE Poland
    Autorzy:
    Krzemińska, E.
    Wiszniewska, J.
    Williams, I.S.
    Powiązania:
    https://bibliotekanauki.pl/articles/2074482.pdf
    Data publikacji:
    2006
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    zircon
    U-Pb SHRIMP geochronology
    closure temperature
    mafic-alkaline magmatism
    Early Carboniferous
    NE Poland
    Opis:
    Three mafic-alkaline intrusive bodies in NE Poland: Ełk, Pisz and Tajno, have been dated recently with U-Pb SHRIMP method. An earlier Rb-Sr whole rock isochron of Ełk syenites pointed to an age 355š4 Ma, while K-Ar age estimates suggested a Late Paleozoic age of Pisz and Tajno rocks, however, in a wide range between 349-291 Ma and 327-289 Ma, respectively. In the paper, we present new geochronological results and discuss the problem of the closure temperatures for different minerals and different isotopic systems used in previous age determinations. Much of the early dating works has been done using K-Ar method. Biotite and K-feldspar retain radiogenic Ar quantitatively below 280 -200şC. Only if magmatic bodies cooled quickly and remained unmetamorphosed, K-Ar and Rb-Sr ages estimate accurately the intrusion emplacement. Zircon used for U-Pb datings has a closure temperature over 800şC, that is comparable to the temperature of magma’s solidus. Therefore U-Pb magmatic zircons dates could be interpreted as an intrusion emplacement ages. The obtained U-Pb results of 347.7 š8 Ma (Ełk) and 345.5š5 Ma (Pisz) have shown very consistent Early Carboniferous age of platform mafic-alkaline magmatic activity. This new U-Pb SHRIMP dating indicates that Ełk and Pisz intrusions are coeval and together with the Tajno alkaline-carbonatite massif could be affined with the Late Devonian Kola Alkaline Carbonatite Province (KACP).
    Źródło:
    Przegląd Geologiczny; 2006, 54, 12; 1093-1098
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Remarks on the Tithonian-Berriasian ammonite biostratigraphy of west central Argentina
    Autorzy:
    Riccardi, A. C.
    Powiązania:
    https://bibliotekanauki.pl/articles/2077329.pdf
    Data publikacji:
    2015
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    Tithonian-Berriasian
    ammonites
    west central Argentina
    calpionellids
    nannofossils
    radiolarians
    geochronology
    tyton
    Berrias
    amonity
    Argentyna
    promienice
    geochronologia
    Opis:
    Status and correlation of Andean ammonite biozones are reviewed. Available calpionellid, nannofossil, and radiolarian data, as well as radioisotopic ages, are also considered, especially when directly related to ammonite zones. There is no attempt to deal with the definition of the Jurassic–Cretaceous limit. Correlation of the V. mendozanum Zone with the Semiforme Zone is ratified, but it is open to question if its lower part should be correlated with the upper part of the Darwini Zone. The Pseudolissoceras zitteli Zone is characterized by an assemblage also recorded from Mexico, Cuba and the Betic Ranges of Spain, indicative of the Semiforme–Fallauxi standard zones. The Aulacosphinctes proximus Zone, which is correlated with the Ponti Standard Zone, appears to be closely related to the overlying Windhauseniceras internispinosum Zone, although its biostratigraphic status needs to be reconsidered. On the basis of ammonites, radiolarians and calpionellids the Windhauseniceras internispinosum Assemblage Zone is approximately equivalent to the Suarites bituberculatum Zone of Mexico, the Paralytohoplites caribbeanus Zone of Cuba and the Simplisphinctes/Microcanthum Zone of the Standard Zonation. The C. alternans Zone could be correlated with the uppermost Microcanthum and “Durangites” zones, although in west central Argentina it could be mostly restricted to levels equivalent to the “Durangites Zone”. The Substeueroceras koeneni Zone ranges into the Occitanica Zone, Subalpina and Privasensis subzones, the A. noduliferum Zone could be equivalent to the Dalmasi Subzone, Occitanica Zone, to lower part of the Boissieri Zone, and the S. damesi Zone could range through the upper part of the Boissieri Zone to the lower part of the Pertransiens Zone. Division of the Substeueroceras koeneni Zone and a precise correlation between the Andean ammonite zones and the international standard require new systematic and stratigraphic studies.
    Źródło:
    Volumina Jurassica; 2015, 13, 2; 23--52
    1896-7876
    1731-3708
    Pojawia się w:
    Volumina Jurassica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    How many extensional stages marked the Variscan gravitational collapse in the Bohemian Massif?
    Autorzy:
    Bárta, Ondřej
    Melichar, Rastislav
    Černý, Jan
    Powiązania:
    https://bibliotekanauki.pl/articles/1836681.pdf
    Data publikacji:
    2021
    Wydawca:
    Polskie Towarzystwo Geologiczne
    Tematy:
    gravitational collapse
    anisotropy of magnetic susceptibility
    U-Pb zircon geochronology
    Variscan orogen
    Central Bohemian plutonic complex
    Opis:
    Tectonic development of the Variscan belt in Central Europe included, besides important compression, also an extensional phase related to gravitational collapse, which governed the origin of many sedimentary basins and magmatic bodies. One of these bodies is the Benešov pluton, featuring primary magmatic fabrics as well as deformational fabrics, related to subsequent extensional stages. Recognition of these fabrics and their links to other significant extension-induced structures in the Bohemicum and Moldanubicum not only sheds new light on the pluton itself but also extends a general knowledge of deformational stages, accompanying gravitational collapse of the Variscan orogen. The authors found that this pluton was strongly strained in a normal-faulting regime under brittle-ductile conditions. The age of deformation is constrained by a magmatic age of 347 ±3 Ma and by the age of Carboniferous sedimentary cover. New data indicate a three-stage extensional history during the phase of gravitational collapse: (1) Tournaisian extension (~350–345 Ma) within arc-related tonalitic intrusions; (2) late Viséan to Serpukhovian extension (~332–320 Ma), connected to the brittle-ductile unroofing and origin of a NE–SW basin system; and (3) Gzhelian to Cisuralian extension (~303–280 Ma), related to normal faulting and sedimentation in “Permo-Carboniferous” troughs, elongated NNE–SSW. Consequently, the gravitational collapse studied involved a complex succession of individual extensional stages, rather than a simple process.
    Źródło:
    Annales Societatis Geologorum Poloniae; 2021, 91, 2; 121-136
    0208-9068
    Pojawia się w:
    Annales Societatis Geologorum Poloniae
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Early Devonian sinistral shearing recorded by retrograde monazite-(Ce) in Oscar II Land, Svalbard
    Autorzy:
    Ziemniak, Grzegorz
    Manecki, Maciej
    Jeanneret, Pauline
    Walczak, Katarzyna
    Kośmińska, Karolina
    Powiązania:
    https://bibliotekanauki.pl/articles/2202387.pdf
    Data publikacji:
    2022
    Wydawca:
    Polskie Towarzystwo Mineralogiczne
    Tematy:
    Retrograde monazite-(Ce)
    Svalbard’s Southwestern Basement Province
    U-Th-total Pb geochronology
    Müllerneset Formation
    Caledonian orogeny
    Opis:
    The Southwestern Basement Province of Svalbard extends northward from Sørkapp Land in the south to Oscar II Land. In the north, the Müllerneset Formation characterized by polymetamorphosed Proterozoic sedimentary rocks crops out. In this study we used an integrated tectonic and petrochronological approach to gain an insight into the structural and metamorphic evolution of the unit and surrounding basement. The Müllerneset Formation consists of two separate tectonic blocks. NNW-SSE trending retrograde foliation is associated with mineral and stretching lineation and kinematic indicators consistent with left-lateral to oblique sinistral shearing in the western block. The eastern block is characterized by the opposite sense of shear that was overturned during the Eurekan event as evidenced by unconformably overlaying Carboniferous sedimentary rocks. Conventional geothermobarometry yields the prograde peak pressure metamorphic conditions of 6.6 - 7.1 kbar at 480 - 520°C followed by peak temperature at 5.1 - 5.9 kbar and 530 - 560°C. Subsequent retrograde greenschist facies overprint is related to left-lateral NNW-SSE trending shearing. Tiny monazite occurs within foliation or overgrows allanite-(Ce), thus is interpreted as growth along a retrograde path. Th-U-total Pb dating of monazite-(Ce) provided an early Caledonian age (ca. 450 Ma) and younger population of ca. 410 ± 8 Ma. This age is consistent with previously reported 40Ar/39Ar cooling ages (410 ± 2 Ma) of muscovite supporting a retrograde growth of monazite. Petrochronological evidence combined with structural observations suggests that the Müllerneset Formation has been tectonically exhumed in the Early Devonian due to the NNW-SSE trending left-lateral shearing. Coeval folding and thrusting in the remaining basement of Oscar II Land to the east indicate a transpressional regime of the deformation in the Early Devonian. Similarly oriented contemporaneous tectonic zones within the Southwestern Basement Province of Svalbard may account for the same set of shear zones dispersing the Ordovician subduction complexes along western Spitsbergen.
    Źródło:
    Mineralogia; 2022, 53, 1; 82--108
    1899-8291
    1899-8526
    Pojawia się w:
    Mineralogia
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Mezoproterozoiczne złoże rud tytanomagnetytowych w suwalskim masywie anortozytowym i jego środowisko geologiczne
    A mesoproterozoic titanomagnetite ore deposit in the suwałki anorthosite massif and its geological environment
    Autorzy:
    Wiszniewska, J.
    Petecki, Z.
    Powiązania:
    https://bibliotekanauki.pl/articles/169985.pdf
    Data publikacji:
    2014
    Wydawca:
    Poltegor-Instytut Instytut Górnictwa Odkrywkowego
    Tematy:
    suwalski masyw anortozytowy
    SMA
    rudy Fe-Ti-V
    geochronologia
    Suwałki Anorthosite Massif
    SAM
    Fe-Ti-V ores
    geochronology
    Opis:
    Rudonośny suwalski masyw anortozytowy (SAM) razem z anortozytowym masywem Kętrzyna i norytową intruzją Sep, występują w obrębie 200 km długości magmowego terenu zwanego kompleksem mazurskim (NE Polska). Rozciągający się pasmowo w kierunku W-E proterozoiczny kompleks mazurski jest zbudowany z różnorodnych skał o składzie od kwaśnych przez pośrednie do zasadowych. Kwarcowe monzonity i granodioryty są najbardziej rozpowszechnionym typem skał w obrębie facji. Kompleks mazurski przecina kilka kompleksów metamorficznej facji granulitowej i amfibolitowej np. kompleks pomorski, dobrzyński, ciechanowski i mazowiecki. Złoża rud Fe-Ti-(V) w anortozytowym masywie suwalskim zostały odkryte we wczesnych latach 60-tych XX wieku, pod miąższym nadkładem fanerozoicznych skał osadowych w obrębie małych dodatnich anomalii magnetycznych, w rejonie Krzemionki, Udryna, Jeleniewa i Jeziora Okrągłego. Złoża te zostały udokumentowane przy pomocy ok. 100 głębokich otworom wiertniczych, do głębokości 2300 m, a zasoby oszacowane w kat. C1 i C2 na ok. 1,5 mld ton rudy tytanomagnetytowej z wanadem, głównie w polu rudnym Krzemionka i Udryn.
    The ore-bearing Suwałki Anorthosite Massif (SAM) together with the Kętrzyn Anorthosite Massif and Sejny norite intrusion are located within 200 km long magmatic terrane called Mazury Complex (NE Poland). The beltiform Proterozoic Mazury Complex is made up of a variety of rocks from felsic and intermidiate to the basic ones. The quartz monzonites and granodiorites are the most widespread rock type within the suite. The belt crosscuts several metamorphic granulite and amphibolite fades units, including Pomorian, Dobrzyń, Ciechanów and Mazovian. Large Fe-Ti-(V) ore deposits of Krzemionka, Udryń, Jeleniewo and Jezioro Okragle have been discovered in early 60-ties, within the small positive magnetic anomalies in the Suwałki Massif and evaluated down to the depth of 2300 m by over 100 boreholes yielding of about 1.5 bilion tons of economic reserves, mostly at Krzemionka and Udryn ore fields.
    Źródło:
    Górnictwo Odkrywkowe; 2014, 55, 2-3; 44-51
    0043-2075
    Pojawia się w:
    Górnictwo Odkrywkowe
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    U-Pb zircon geochronology of high-grade charnockites - exploration of pre-Mesoproterozoic crust in the Mazury Complex area
    Autorzy:
    Krzemińska, Ewa
    Łukawska, Aleksandra
    Bagiński, Bogusław
    Powiązania:
    https://bibliotekanauki.pl/articles/139214.pdf
    Data publikacji:
    2019
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    magmatic protolith
    U-Pb geochronology
    dry metamorphism
    continental margin
    protolit magmowy
    geochronologia U-Pb
    metamorfizm suchy
    margines kontynentalny
    Opis:
    Charnockites – i.e., orthopyroxene-bearing felsic rocks – were formed in a deep-seated dry environment, either under plutonic or high-grade metamorphic conditions. Most charnockites known from the crystalline basement of Poland appear to be of Mesoproterozoic age (1.50–1.54 Ga), cogenetic with the Suwałki Anorthosite Massif, and associated with mangerite and granite members forming the AMCG suite of the Mazury Complex. Genetically distinct rocks, characterised by the presence of anhydrous minerals, e.g., orthopyroxene and garnet, were also recognised along 592 m of the Łanowicze PIG-1 borehole section, within the AMCG suite. U-Pb geochronology by sensitive high resolution ion microprobe (SHRIMP) was used to date the complexly zoned zircons. The ages of crystallisation of the charnockite protoliths from various depths at 1837 ± 7, 1850 ± 9, 1842 ± 6, and 1881 ± 16 Ma makes these rocks the oldest dated crust within this part of the Polish basement. The Łanowicze PIG-1 borehole section bears components from neighbouring tectonic domains known from Lithuania: the West and Middle Lithuanian (WL/MLD) domains considered as a continental margin at 1.84–1.86 Ga and the fragmented Latvia-East Lithuania (LEL) domain, where the oldest continental crust was generated at c. 1.89–1.87 Ga. The metamorphic zircon overgrowths document a high-grade event at 1.79 Ga and then constrained at 1.5 Ga. Dating of pre-Mesoproterozoic crust cryptic within the AMCG Mazury Complex provides valuable information on the nature of the pre-existing blocks formed during the long lasting Svecofennian orogeny.
    Źródło:
    Acta Geologica Polonica; 2019, 69, 4; 489-511
    0001-5709
    Pojawia się w:
    Acta Geologica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Rewizja wieku "najstarszych" skał w podłożu krystalicznym północno-wschodniej Polski
    Revision of the "oldest" rocks age in the crystalline basement of NE Poland
    Autorzy:
    Krzemińska, E.
    Wiszniewska, J.
    Williams, I.S.
    Powiązania:
    https://bibliotekanauki.pl/articles/2074437.pdf
    Data publikacji:
    2006
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    pegmatyt
    monacyt
    ziarna cyrkonu
    mikroskopia elektronowa
    wysokopróżniowy mikroskop skaningowy
    zircon
    monazite
    U-Pb SHRIMP geochronology
    Late Paleoproterozoic
    NE Poland
    Opis:
    The oldest geochronological results between 2.69–2.57 Ga was previously obtained by using K–Ar method on biotite from pegmatite from Jastrzębna IG–1 borehole. In consequence, in many published reports up to 1998, the Mazowsze (or Masovian) granitoid massif has been regarded as Archean age structure. Therewithal, other rocks in the area, e.g. Bargłów gneiss sequence traditionally were described as Archean in age. In the paper we present new U–Pb SHRIMP zircon and monazite results for above mentioned rocks which have been considered as Archean. Cathodoluminescence images and SHRIMP analysis were carried out for zircons and monazites from Jastrzebna IG–1 pegmatite of 514 m depth (a historical sample previously dated by K–Ar method) and for zircon magmatic cores from Bargłów IG–2 orthogneiss of the 708 m depth. The obtained U–Pb ages of 1826 š12 Ma (zircon) and 1789š34 Ma (monazite), and 1835š28 Ma (zircon) for two rock samples respectively have shown Paleoproterozoic origin. Only 4 of the 24 analysed zircons have clearly discordant results, which are all from the Jastrzebna pegmatite, where Pb–loss was possible (in partially metamict U–rich zircon grains). The new U–Pb SHRIMP dating indicates that Jastrzębna pegmatite and Bargłów magmatic protolith of the orthogneiss is only Late Paleoproterozoic in age and in general about 700 Ma younger than previously reported by K–Ar method. Therefore, there is no unequivocal evidence of the presence of Archean rocks in crystalline basement of NE Poland. This study has been undertaken as a part of a collaborative research agreement between the Polish Geological Institute and Geochronology and Isotope Geochemistry Research School of Earth Sciences of the Australian National University in Canberra.
    Źródło:
    Przegląd Geologiczny; 2006, 54, 11; 967-973
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Magmatic episodes in the Holy Cross Mountains, Poland – a new contribution from multi-age zircon populations
    Epizody magmowe w Górach Świętokrzyskich – nowe dane o populacjach cyrkonu różnego wieku
    Autorzy:
    Krzemińska, Ewa
    Krzemiński, Leszek
    Powiązania:
    https://bibliotekanauki.pl/articles/2061589.pdf
    Data publikacji:
    2019
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    U-Pb geochronology
    zircon
    antecrysts
    xenocrysts
    diabase
    lamprophyre
    tuff
    Łysogóry region
    Kielce Region
    geochronologia U-Pb
    cyrkon
    antekryształy
    ksenokryształy
    diabazy
    lamprofiry
    tuf
    region łysogórski
    region kielecki
    Opis:
    This contribution reports on new U-Pb zircon age data from magmatic rocks from the Holy Cross Mountains (HCM) of Poland. The analyzed samples were taken from lamprophyre and diabase veins of Podkranów and Janowice-2 as well as from tuff horizon of Kielce Beds (Ludlow). Internal morphologies have been investigated by SEM-BSE and cathodoluminescence images and they have been used as a guide for the selection of genetically various type of grains, e.g. potential auto-, ante- and xenocrysts, that were analyzed by ion microprobe. The U-Pb age of the magmatic events at 414.2 ±6.6 Ma (Kielce tuff), 322 ±12 Ma (Podkranów, lamprophyre), and 300±10 Ma (Janowice-2, diabase) confirmed the time frame of known magmatic activity reported within the HCM, as determined by 40Ar/39Ar geochronology in previous studies. The zircon investigation revealed also multiple populations with record of an earlier pulse of magma system (antecrysts), as well as abundant xenocrysts.
    W artykule przedstawiono nowe oznaczenia wieku U-Pb cyrkonu w skałach magmowych z obszaru Gór Świętokrzyskich (HCM). Próbki pobrano z żył lamprofiru i diabazu z Podkranowa i Janowic-2 oraz z poziomu tufu w warstwach kieleckich (ludlow). Morfologię i wewnętrzne cechy budowy ziaren zbadano za pomocą obrazów SEM-BSE i katodoluminescencji SEM, stosując je jako przewodnik do selekcji genetycznie różnych typów ziaren, potencjalnych auto-, ante- i ksenokryształów, które były analizowane na mikrosondzie jonowej. Wiek U-Pb epizodów magmowych, 414,2 ±6,6 Ma (Kielce, tuf), 322 ±12 Ma (Podkranów, lamprofir) i 300 ±10 Ma (Janowice-2, diabaz), potwierdza znane z wcześniejszych publikacji ramy czasowe aktywności magmowej na obszarze HCM oznaczone metodą 40Ar/39Ar. Badania wieku U-Pb cyrkonu ujawniły także szereg populacji z zapisem wcześniejszych impulsów magmowych (antekryształy) i licznych ksenokryształów.
    Źródło:
    Biuletyn Państwowego Instytutu Geologicznego; 2019, 474; 43--57
    0867-6143
    Pojawia się w:
    Biuletyn Państwowego Instytutu Geologicznego
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
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