Počet záznamů: 1
Middle/Late Cambrian intracontinental rifting in the central West Sudetes, NE Bohemian Massif (Czech Republic): geochemistry and petrogenesis of the bimodal metavolcanic rocks
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SYSNO ASEP 0145353 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Middle/Late Cambrian intracontinental rifting in the central West Sudetes, NE Bohemian Massif (Czech Republic): geochemistry and petrogenesis of the bimodal metavolcanic rocks Tvůrce(i) Dostal, J. (CA)
Patočka, František (GLU-S) SAI
Pin, CH. (FR)Zdroj.dok. Geological Journal - ISSN 0072-1050
Roč. 36, č. 1 (2001), s. 1-17Poč.str. 17 s. Jazyk dok. eng - angličtina Země vyd. GB - Velká Británie Klíč. slova bimodal metavolcanics ; Early Palaeozoic ; northern Gondwana Vědní obor RIV DB - Geologie a mineralogie CEP GA205/93/0341 GA ČR - Grantová agentura ČR IAA3111102 GA AV ČR - Akademie věd CEZ AV0Z3013912 - GLU-S UT WOS 000168302400001 EID SCOPUS 0035050075 DOI 10.1002/gj.872 Anotace The Early Palaeozoic East Krkonoše Complex situated in the central West Sudetes, NE Bohemian Massif, is a volcano-sedimentary suite containing abundant mafic and felsic volcanics metamorphosed to greenschist facies.The trace element distribution patterns and Nd isotope signatures (ENd500 = +3.1 to +6.6) of the metabasalts indicate that they may be related to a rising mantle diapir associated with intracontinental rifting. At the early stage, limited melting of an upwelling asthenosphere produced alkali basalts and enriched tholeiites which compositionally resembled oceanic island basalts. A later stage of rifting larger degrees of melting at shallower depths generated tholeiitic basalts with E-MORB to N-MORB characteristics.The values of (87Sr/86Sr)i = 0.706 and ENd500 = -5,1 of the metarhyolites as well as the lack of rocks with intermediate composition suggest that the felsic rocks were formed by partial melting of continental crust triggered by mantle melts.The geochemistry of the bimodal metavolcanics and their association with abundant terrigenous metasediments suggest that the felsic-mafic volcanic suite was generated during an early stage of intracontinental rifting. This process, widespread in Western and Central Europe during the Early Palaeozoic, is an evidence of large-scale fragmentation of the northern margin of the Gondwana supercontinent. Pracoviště Geologický ústav Kontakt Jana Popelková, popelkova@gli.cas.cz, Sabina Janíčková, Tel.: 233 087 272 Rok sběru 2002
Počet záznamů: 1