Introduction
Periodicals
Bulletin mineralogicko-petrologického oddělení Národního muzea v Praze
2011/19/2
Mladopaleozoické vulkanity Žatecka, sz. Čechy
Mladopaleozoické vulkanity Žatecka, sz. Čechy
Zdeněk Řanda, Ferry Fediuk
| Pages | 138-144 |
|---|---|
| Citation | ŘANDA, Zdeněk a FEDIUK, Ferry. Mladopaleozoické vulkanity Žatecka, sz. Čechy. Bulletin mineralogicko-petrologického oddělení Národního muzea v Praze. Prague: National Museum, 2011, 19(2), 138-144. ISSN 1211-0329 (print), 1804-6495 (online). Also available from: https://publikace.nm.cz/en/periodicals/bmpholnrhmvp/19-2/mladopaleozoicke-vulkanity-zatecka-sz-cechy |
A series of bore holes around the town of Žatec revealed a large complex of Permo-Carboniferous (Gzhelian - Asselian) mafic volcanics 150 to 400 m beneath the Tertiary and Cretaceous sedimentary cover. The extent of it is estimated to 80 km2 with the maximum thickness of 53 m consisting of several lava sheets. Peripheral volcanoclastic admixture in sediments enlarges the area to roughly 250 km2. The rocks show mostly basaltic trachyandesite and in the minority of cases basaltic andesite compositions. Their chemistry is A/SA transitional, high-K and metaluminous, Th highly prevails over U. Acid volcanics, occurring frequently in the vicinity of the area, are entirely absent here. Some trace elements signature indicates a destructive plate margin affinity of these within plate volcanics.
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