Zircon U-Pb Dating of Magmatism and Mineralizing Hydrothermal Activity in the Variscan Karkonosze Massif and Its Eastern Metamorphic Cover (SW Poland)
| Autor: | Holly J. Stein, Stanisław Z. Mikulski, Ian S. Williams, Jan Wierchowiec |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Karkonosze Pluton
010506 paleontology Mineralization (geology) lcsh:QE351-399.2 Pluton Geochemistry 010502 geochemistry & geophysics 01 natural sciences SHRIMP U-Pb zircon geochronology Sudetes Metasomatism 0105 earth and related environmental sciences Variscan magmatism geography geography.geographical_feature_category Sensitive high-resolution ion microprobe lcsh:Mineralogy Geology Massif Geotechnical Engineering and Engineering Geology Re-Os geochronology Porphyritic Igneous rock intrusion related Mo-W-Sn- Fe-Cu-As-REE-Th-U mineralization Zircon |
| Zdroj: | Minerals, Vol 10, Iss 787, p 787 (2020) Minerals Volume 10 Issue 9 |
| Popis: | SHRIMP (Sensitive high resolution ion microprobe) zircon U-Pb dating of the two main igneous rocks types in the Karkonosze Pluton, porphyritic and equigranular monzogranite, yield 206Pb/238U ages between 312.0 ± 2.9 and 306.9 ± 3.0 Ma. These coincide, within uncertainty, with the majority of previous dates from the pluton, which indicate development of the main magmatic processes between ca. 315 and 303 Ma. They also coincide with molybdenite and sulfide Re-Os ages from ore deposits developed during magmatic and pneumatolitic-hydrothermal (e.g., Szklarska Poręba Huta and Michałowice) or/and metasomatic and hydrothermal (e.g., Kowary, Czarnó w and Miedzianka) processes forming Mo-W-Sn-Fe-Cu-As-REE-Y-Nb-Th-U mineralization. The 206Pb/238U zircon age of 300.7 ± 2.4 Ma from a rhyolite porphyry dyke (with disseminated base metal sulfide mineralization) in the Miedzianka Cu-(U) deposit coincides with the development of regional tectonic processes along the Intra-Sudetic Fault. Moreover, at the end-Carboniferous, transition from a collisional to within-plate tectonic setting in the central part of the European Variscides introduced volcanism in the Intra-Sudetic Basin. Together, these processes produced brecciation of older ore mineralization, as well as metal remobilization and deposition of younger medium- and low-temperature hydrothermal mineralization (mainly Cu-Fe-Zn-Pb-Ag-Au-Bi-Se, and Th-U), which became superimposed on earlier high-temperature Mo-W-Sn- Fe-As-Cu-REE mineralization. A few 206Pb/238U ages > 320 Ma remain to be reconciled, but might be due to the high U and Th contents of the zircon and the strong influence of overprinting pneumatolitic-hydrothermal processes. |
| Databáze: | OpenAIRE |
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