Počet záznamů: 1
Cambro–Ordovician anatexis and magmatic recycling at the thinned Gondwana margin: new constraints from the Kouřim Unit, Bohemian Massif
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SYSNO ASEP 0508957 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Cambro–Ordovician anatexis and magmatic recycling at the thinned Gondwana margin: new constraints from the Kouřim Unit, Bohemian Massif Tvůrce(i) Soejono, I. (CZ)
Machek, Matěj (GFU-E) ORCID, RID
Sláma, Jiří (GLU-S) SAI, RID, ORCID
Janoušek, V. (CZ)
Kohút, M. (SK)Zdroj.dok. Journal of the Geological Society. - : Geological Society Publishing House - ISSN 0016-7649
Roč. 177, č. 2 (2020), s. 325-341Poč.str. 17 s. Forma vydání Tištěná - P Jazyk dok. eng - angličtina Země vyd. GB - Velká Británie Klíč. slova Kouřim Unit ; Cambro-Ordovician ; lithospheric extension ; crustal anatexis ; Gondwana passive margin ; Bohemian Massif Vědní obor RIV DB - Geologie a mineralogie Obor OECD Geology Vědní obor RIV – spolupráce Geologický ústav - Geologie a mineralogie Způsob publikování Omezený přístup Institucionální podpora GFU-E - RVO:67985530 ; GLU-S - RVO:67985831 UT WOS 000537276100007 EID SCOPUS 85081136852 DOI 10.1144/jgs2019-037 Anotace The Kouřim Unit represents one of the largest pre-Variscan meta-igneous complexes in the Bohemian Massif and a geochronological, whole-rock geochemical and Sr-Nd isotopic study was conducted to better understand the magmatic evolution of the Early Paleozoic Gondwana margin. Five orthogneisses yield U-Pb zircon ages ranging from 492 +/- 4 to 484 +/- 2 Ma. Two leucogranites give U-Pb zircon ages of 500 +/- 4 and 485 +/- 2 Ma, interpreted to be inherited from their orthogneiss host rock. Two samples from the metasedimentary host rock are dominated by Neoproterozoic-Cambrian detrital zircons. The abundance of zircon inheritance in the orthogneisses and whole-rock Sr-Nd isotopic composition imply an origin from relatively mature continental crustal material. The subalkaline, subaluminous-slightly peraluminous and high-K calc-alkaline arc-like geochemical signature of the orthogneisses is interpreted as inherited from the recycled Cadomian metasedimentary source and both the magmatic and metasedimentary rocks are correlated with similar occurrences in the adjacent Moldanubicum and Tepla-Barrandian Unit. The Late Cambrian-Early Ordovician magmatic activity is linked to crustal anatexis, which was probably initiated by thermal and gravitational relaxation of the thickened Cadomian arc-type crust, followed by lithospheric thinning assisted by far-field forces. The extensional event led to the formation of a passive margin associated with the opening of the Rheic Ocean. Pracoviště Geofyzikální ústav Kontakt Hana Krejzlíková, kniha@ig.cas.cz, Tel.: 267 103 028 Rok sběru 2021 Elektronická adresa https://jgs.lyellcollection.org/content/177/2/325.abstract
Počet záznamů: 1