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Wyszukujesz frazę "Zircon" wg kryterium: Temat


Tytuł:
Zirconium silicates in a peralkaline granite: a record of the interplay of magmatic and hydrothermal processes (Ilímaussaq complex, Greenland)
Autorzy:
Cegiełka, Małgorzata
Bagiński, Bogusław
Macdonald, Ray
Belkin, Harvey E.
Kotowski, Jakub
Upton, Brian G. J.
Powiązania:
https://bibliotekanauki.pl/articles/2086665.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
peralkaline granite
Ilímaussaq complex
zircon
catapleiite
Elpidite
hydrothermal fluids
granit peralkaliczny
kompleks Ilimaussaq
cyrkon
płyny hydrotermalne
Opis:
Compositional and textural data are presented for zircon, secondary Zr-silicates, catapleiite and elpidite in a peralkaline granite from the Ilímaussaq complex, south Greenland. The zircon is essentially stoichiometric, with (Zr + Hf + Si) = 1.96–1.98 a.p.f.u. The secondary Zr-silicates show a wide range of Zr/Si atomic ratios (0.13–0.79). The catapleiite varies from close to stoichiometric to a Na-depleted type showing cation deficiency (5.2–5.8 a.p.f.u.). Elpidite shows similar variations (7.2–9.0 a.p.f.u.). Textural relationships between the Zr phases are interpreted to show that magmatic zircon interacted with hydrous fluids exsolved from the magma to form the secondary Zr-silicates. Formation of catapleiite was late-magmatic, in equilibrium with a Na-Si-bearing fluid. This was followed by the crystallization of elpidite, the fluid having a different Na/Si ratio. Both catapleiite and elpidite experienced Na-loss during late-stage hydrothermal alteration.
Źródło:
Acta Geologica Polonica; 2022, 72, 2; 235--245
0001-5709
Pojawia się w:
Acta Geologica Polonica
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:
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:
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:
W poszukiwaniu fragmentów najstarszej skorupy kontynentalnej na Labradorze
Searching for pieces of the oldest crust in Labrador
Autorzy:
Kusiak, M. A.
Sałacińska, A.
Powiązania:
https://bibliotekanauki.pl/articles/2075545.pdf
Data publikacji:
2016
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
młoda Ziemia
blok Saglek
Labrador
granitoid
cyrkon
early Earth
Saglek Block
granitoids
zircon
Opis:
There are few unresolved questions in the Earth Sciences which generate as much debate as the nature of the Hadean Earth: i.e. the rock record between the Earth’s formation and about 3.8 billion years ago. Current knowledge of the nature and origin of the earliest crust comes largely from studies of the mineral zircon (ZrSiO4). The oldest zircon grains on Earth (4.46 Ga) are found in Jack Hills, Australia. They represent a time capsule of what the Earth was like from ca. 4.4-4.0 Ga during the Hadean. The other ancien rocks (>3.8 Ga) are preserved in Antarctica, Canada, China, Greenland, Labrador, Western Australia and Swaziland, with the oldest known rochi on Earth from the Acasta gneiss in Northern Canada, dated at 4.03 Ga. Most likely, the second oldest rock record in the world (>3.9 Ga) may be derivedfrom the Nanok gneiss in the Nain Complex of the Saglek-Hebron area in the northern part of the Labrador Peninsula. Extensive investigation of these rocks will allowfurther characterizing the nature of the earliest preserved crust.
Źródło:
Przegląd Geologiczny; 2016, 64, 11; 896--901
0033-2151
Pojawia się w:
Przegląd Geologiczny
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:
Thorite inclusions in zircon of the monzogranite, Lower Nubia, SW Egypt
Autorzy:
Hassan, Kamaleldin M.
Brunarska, Irena
Powiązania:
https://bibliotekanauki.pl/articles/46220137.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Mineralogiczne
Tematy:
Zircon
thorite
syngenetic inclusions
accessory minerals
metaluminous granite
Nubian Desert
Opis:
This report presents the results of a petrographical and mineralogical (optical microscopy, BSE-EDS image analysis) study of zircon in samples from the Lower Nubian monzogranite. The mineral occurs as smaller grains (< 80 µm) in a finegrained quartz-feldspar-matrix, coexisting with other accessory minerals including biotite, clinochlore, titanite, and britholite-(Ce). Zircon is also present within biotite and britholite-(Ce), suggesting that it started crystallization at about the same time as these two minerals. Two types of thorite inclusions within zircon are reported in this study. Type 1 is widely distributed throughout the zircon grain, forming crystallites of which each is typically < 1 µm in size. Type 2 is relatively larger (5-15 µm) and occurs only in one part of the grain. For the thorite inclusions, three possible origins are briefly discussed: (1) exsolution of thorite from zircon; (2) dissolution/reprecipitation of zircon; and (3) growth syngenetically with zircon. Of these potential hypotheses, the syngenetic growth model seems more favorable for zircon-thorite intergrowths than the other two hypotheses. Thorite inclusions and their host zircons seem to have grown from magma rather than hydrothermal or supercritical solutions. Here, they have primary textures and consistent chemical compositions that are consistent with whole-rock geochemistry.
Źródło:
Mineralogia; 2023, 54, 1; 69-77
1899-8291
1899-8526
Pojawia się w:
Mineralogia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Saxothuringian Terrane affinity of the metamorphic Stachów Complex (Strzelin Massif, Fore-Sudetic Block, Poland) inferred from zircon ages
Autorzy:
Oberc-Dziedzic, T.
Kryza, R.
Madej, S.
Pin, C.
Powiązania:
https://bibliotekanauki.pl/articles/2059781.pdf
Data publikacji:
2018
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Stachów Complex
Saxothuringian Terrane
SHRIMP zircon ages
Strzelin Massif
Opis:
The Saxothuringian Terrane defined in the western part of the Bohemian Massif is regarded to have easterly continuations in the Karkonosze–Izera Massif, the Kamieniec Ząbkowicki Belt and the Orlica–Śnieżnik Dome. All these units comprise Early Ordovician (~500 Ma) metagranites associated with mica schists. Even more to the east, ~500 Ma metagranites and metasedimentary rocks occur also in the Strzelin Massif of the East Sudetes, where they are known as the pale and dark Stachów gneisses, respectively. Altogether, these rocks form the Stachów Complex which was thrust on the Strzelin Complex of the Brunovistulicum Terrane during the Variscan Orogeny. The contribution presents lines of evidence for a Saxothuringian affinity of the Stachów Complex rocks: (1) the new SHRIMP U-Pb age data of zircons from both the pale and dark Stachów gneisses; (2) the indication that the zircon age spectra from the ~500 Ma granitoids and their accompanying metasedimentary rocks are similar to those found in other parts of the Sudetes; (3) the “Armorican” age pattern of inherited zircons of the pale Stachów gneisses, as also observed in the Saxothuringian Terrane; (4) the similarity of trace elements and Sm-Nd isotope data of the Stachów gneisses and correlative rocks from the Karkonosze–Izera Massif and the Orlica–Śnieżnik Dome.
Źródło:
Geological Quarterly; 2018, 62, 2; 237--256
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and Characterization of New Refractory Coatings Based on Talc, Cordierite, Zircon and Mullite Fillers for Lost Foam Casting Process
Synteza i charakterystyka nowych powłok ogniotrwałych na bazie talku, kordierytu, cyrkonii i mulitu do odlewania metodą piany traconej
Autorzy:
Prstić, A.
Aćimović-Pavlović, Z.
Terzić, A.
Pavlović, L.
Powiązania:
https://bibliotekanauki.pl/articles/352726.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high-temperature materials
refractory coatings
talc
cordierite
zircon
mullite
lost foam casting
talk
materiały wysokotemperaturowe
kordieryt
cyrkonia
mulit
metoda piany traconej
Opis:
Refractory coatings based on different refractory fillers (talc, cordierite, zircon and mullite) for application in Lost Foam casting process were investigated. Design and optimization of the coatings composition with controlled, rheological properties included, and consequently synthesis were achieved by application of different coating components, namely different suspension agents and fillers and by alteration of the coating production procedure. Morphologic and microstructural analysis of fillers was carried out by means of scanning electronic microscope. X-ray diffraction analysis by means of X-ray diffractometer was applied in determination and monitoring the phase composition changes of the refractory fillers. An analysis of the particle size and shape was carried out by means of the PC software application package OZARIA 2.5. To assess the effects of application of individual refractory coatings, a detailed investigation of structural and mechanical properties of the moldings obtained was performed. Highlight was placed on revealing and analyzing surface and volume defects present on moldings. Radiographic molding tests were carried out by means of the X-ray device SAIFORT type-S200. Attained results are essential for the synthesis of refractory coatings based on high-temperature fillers and their applications in Lost Foam casting process for manufacturing of moldings with in-advance-set properties.
W pracy przedstawiono wyniki badań materiałów wysokotemperaturowych - powłok ogniotrwałych na bazie talku, kordierytu. cyrkonii i mulitu, które są stosowane w procesie odlewania metodą piany traconej. Projektowanie i optymalizację składu powłoki o kontrolowanych właściwościach teologicznych, a następnie syntezę osiągnięto poprzez zastosowanie różnych skład- ników powłok, tj. różnych stabilizatorów zawiesiny i wypełniaczy oraz poprzez zmiany w procesie produkcji powłok. Analizę morfologiczną i mikrostruktura!ną wypełniaczy przeprowadzono za pomocą elektronowego mikroskopu skaningowego. Analizę dyfrakcji promieni rentgenowskich zastosowano do określania i monitorowania zmian składu fazowego wypełniaczy ognio- trwałych. Analizę wielkości i kształtu cząstek przeprowadzono za pomocą pakietu oprogramowania użytkowego PC OZARIA 2.5. Żeby ocenić skutki stosowania poszczególnych powłok ogniotrwałych, przeprowadzono szczegółowe badania właściwości strukturalnych i mechanicznych otrzymanych form. Nacisk został położony na ujawnienie i analizę defektów powierzchni i objętości obecnych w formach. Radiograficzne testy formowania przeprowadzono za pomocą urządzenia SAJFORT typu S200. Uzyskane wyniki są niezbędne do syntezy powłok ogniotrwałych w oparciu o wysokotemperaturowe wypełniacze i ich zastosowań w procesie odlewania metodą piany traconej do produkcji form o z góry ustalonych właściwościach.
Źródło:
Archives of Metallurgy and Materials; 2014, 59, 1; 89-95
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Silesian Ridge in the light of petrological analyses and LA-ICP MS U-Pb analyses of the cohesive debrites from the Istebna Formation (Silesian Nappe, Outer Western Carpathians, Poland)
Autorzy:
Szczuka, Monika
Gawęda, Aleksandra
Waśkowska, Anna
Golonka, Jan
Szopa, Krzysztof
Chew, David
Drakou, Foteini
Powiązania:
https://bibliotekanauki.pl/articles/2187194.pdf
Data publikacji:
2022
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Outer Carpathians
Silesian Ridge
exotic clasts
U-Pb dating
zircon
rutile
Opis:
Exotic clasts present in flysch deposits of the Western Outer Carpathians enable investigation and reconstruction of the eroded crystalline basement of the Silesian Ridge. The flysch rocks of the Istebna Formation (Jasnowice Member: Paleocene) in the Silesian Nappe contain magmatic and metamorphic clasts derived from the Silesian Ridge basement. The crystalline rock fragments acquired from cohesive debrites were analyzed petrographically and geochemically, and zircon and rutile crystals were subject to LA-ICP-MS U-Pb dating. Granitoid clasts yielded Meso-Variscan U-Pb zircon ages (325.7 and 330.6 Ma), with older (Neoproterozoic to Paleoproterozoic) inherited cores and eNd330 = –12.0 (TDM age of 1.98 Ga). The orthogneiss clast yielded a protolith age of 1635 Ma and fingerprint of thermal reworking at ~288 Ma. Zircon crystals from the detrital clasts yielded similar U-Pb zircon ages to the granitoid clasts (311.5 to 391 and 331 Ma). The rutile crystals from sandstone yielded concordia age of 344.7 Ma. Zircon crystals from paragneiss, interpreted as a granitoid envelope, yielded 238U/206Pb ages between 557 and 686 Ma and include an inherited core of age ~1207.4 ±33.8 Ma. Age data from exotic clasts and the detrital zircon and rutile fraction suggest the core part of the Silesian Ridge was a Neoproterozoic to Mesoproterozoic envelope intruded by Meso-Variscan granitoid plutons.
Źródło:
Geological Quarterly; 2022, 66, 2; art. no. 20
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:
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:
Relacje metodyczne i wiekowe pomiędzy analizą trakową a potasowo-argonową na przykładzie masywu Karkonoszy i jego osłony
Methodology and age relations of the fission track and K-Ar methods : the case of the Karkonosze massif and its envelope
Autorzy:
Jarmołowicz-Szulc, K.
Powiązania:
https://bibliotekanauki.pl/articles/2061929.pdf
Data publikacji:
2014
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
traki
apatyt
cyrkon
metoda K-Ar
procedury analityczne
fission tracks
apatite
zircon
K-Ar method
analytical procedures
Opis:
W kontekście coraz większego znaczenia metod izotopowych w Polsce i zrozumienia ich możliwości interpretacyjnych, przedstawiono porównanie metodyczne i wiekowe analizy trakowej i oznaczeń metodą potasowo-argonową (K-Ar) w odniesieniu do minerałów budujących skały masywu Karkonoszy oraz jego północnej osłony. Prezentowane wyniki stanowią kompilację wcześniejszych oznaczeń trakowych z obszaru karkonosko-izerskiego (Jarmołowicz-Szulc, 1984), oznaczeń K-Ar z tego samego obszaru (Jarmołowicz-Szulc i in., 2009) oraz nowszych metodycznie danych literaturowych z masywu Karkonoszy (Danišik i in., 2010). Wykazano zaletę metody trakowej, którą są przede wszystkim możliwości interpretacyjne związane z datowaniem wypiętrzenia i/lub pogrzebania w historii geologicznej skał. Pokazano również walory metody K-Ar, umożliwiającej m.in. uzyskanie wartości wieku oziębiania np. po wypiętrzeniu plutonu.
Isotopic methods have been gaining their importance in Poland in last decades. The understanding on the interpretation potential of isotopic determinations of minerals has been growing up as well. In that context, age relations and methodology of the fission track and K-Ar methods have been presented based on the case of minerals forming rocks of the Karkonosze Massif and its northern metamorphic envelope. The presented results are the compilation of earlier fission track determinations from the Karkonosze-Izera Block (Jarmołowicz-Szulc, 1984), K-Ar data from the same area (Jarmołowicz-Szulc et al., 2009) and newer methodological data from the Karkonosze granitoid (Danišik et al., 2010). Advantages of the fission track method have been shown, i.e., interpretation possibilities of burial and exhumation in geological history of rocks. Importance of the K-Ar method has been presented, in that determination of a cooling age after the pluton uplift.
Źródło:
Biuletyn Państwowego Instytutu Geologicznego; 2014, 458; 31--37
0867-6143
Pojawia się w:
Biuletyn Państwowego Instytutu Geologicznego
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Provenance petrological study of the Upper Vendian and Cambrian clastic material; foreland of the Pomeranian Caledonides (northern Poland)
Autorzy:
Sikorska, M.
Powiązania:
https://bibliotekanauki.pl/articles/2059450.pdf
Data publikacji:
2000
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
northern Poland
Lower Cambrian
Upper Vendian
clastic material
zircon
Opis:
The provenance of clastic material in the oldest part of the sedimentary cover of the East European Craton, in northern Poland, is analysed. Analysis of the Żarnowiec Formation sandstones (Upper Vendian-lowest Cambrian) confirm earlier views of a local origin. The crystalline basement in the Kościerzyna IG 1 region mainly yielded enderbitic detritus while that in the Gdańsk IG 1 region provided migmatitic detritus. Triangle diagrams of the overlying, mature, sandy marine Cambrian show unequivocally that the detritus was transported from the craton interior. Analysis of mono- and polycrystalline quartz and cathodoluminescence (CL) analysis indicates erosion of metamorphic, magmatic and sedimentary rocks, and this is confirmed by CL observations of zircons. These results are consistent with the view that the Upper Vendian and Cambrian strata on the Pomeranian Caledonides foreland were formed on the passive margin of Baltica.
Źródło:
Geological Quarterly; 2000, 44, 3; 237-247
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Niemcza diorites and moznodiorites (Sudetes, SW Poland) : a record of changing geotectonic setting at ca. 340 Ma
Autorzy:
Pietranik, A.
Storey, C.
Kierczak, J.
Powiązania:
https://bibliotekanauki.pl/articles/2059736.pdf
Data publikacji:
2013
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Variscidies
Niemcza Zone
diorites
LA-ICP-MS zircon age
potassic magmatism
Opis:
Granites sensu lato in the Sudetes intruded in several episodes during the Variscan orogeny recording different stages of crust and mantle evolution. Correlating precise ages with geochemistry of the Variscan granites provides information on the evolution of these sources within the Variscan orogen. The Variscan intrusive rocks from the Niemcza Zone (Bohemian Massif, Sudetes, SW Poland) include undeformed dioritic to syenitic rocks and magmatically foliated granodiorites. In this study we analysed low SiO2 (48–53 wt.%) monzodioritic rocks from Przedborowa and Koźmice. The monzodiorites contain late-magmatic zircons with ages of 341.8 ± 1.9 Ma for Przedborowa and 335.6 ± 2.3 Ma for Koźmice, interpreted as emplacement ages of the dioritic magmas. Older Przedborowa rocks are lower in K, Mg, Rb and Ni than the Koźmice rocks and similar compositional trend is also observed in the Central Bohemian Plutonic Complex. The implication is that the mantle underlying the Niemcza Zone became more enriched from ca. 342 to ca. 336 Ma, probably following the collision of the Saxothuringian and Moldanubian/Lugian domains. The magmatism related to the collision occurred ca. 12 Ma later than that in the Central Bohemian Plutonic Complex, but was accompanied by a similar change in magma chemistry from high-K (Przedborowa) to shoshonitic (Koźmice, Kośmin enclaves) and probably to ultrapotassic (Wilków Wielki).
Źródło:
Geological Quarterly; 2013, 57, 2; 325--334
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł

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