Cenozoic Intraplate Alkaline Volcanism of Western Bohemia

• Published in: Studia geophysica et geodaetica Vol. 44; no. 2; pp. 346 - 351
• Main Authors: Ulrych, Jaromír, Cajz, Vladimír, Pivec, Edvin, Novák, Jirí Karel, Nekovarík, Cestmír, Balogh, Kadosa
• Format: Journal Article
• Language: English
• Published: Prague Springer Nature B.V 01-01-2000
• Subjects: Cenozoic; Graben; Magma; Plate tectonics; Rhyolite; Rhyolites; Seismology; Trachyte; Volcanic activity; Volcanism; Volcanoes
• ISSN: 0039-3169; 1573-1626
• DOI: 10.1023/A:1022131413783

Three independent volcanic suites have been recognised in W Bohemia: (i) the old unimodal alkaline ol. nephelinite-tephrite (29-19 Ma) in the Ohře Rift, (ii) two contemporaneous weakly (trachybasalt/trachyandesite-trachyte/rhyolite; 13-11 Ma) and strongly (ol. nephelinite-tephrite/basanite; 12-8 Ma) alkaline series in the flank of the Cheb-Domažlice Graben formed by the Teplá Highland and (iii) the young unimodal ol. melilitite/ol. nephelinite alkaline suite (2.0-0.12 Ma) at the intersection of the above mentioned structures in the Cheb Basin. The magmas of all the suites are mantle-derived and, in the case of the Cheb-Domažlice Graben series, associated with the AFC process. Two main fault systems: (i) ENE-WSW and (ii) NNW-SSE are developed in W Bohemia, corresponding to the directions of the two prominent taphrogenic structures. The southwesterly continuation of the Ohře Rift across the Mariánské Lázně Fault is marked by volcanics only.