Geochemical characteristics of the high- and low-Ti basaltic rocks from the uplifted shoulder of the Ohře (Eger) Rift, Western Bohemia

0350041 - GLÚ 2011 RIV DE eng J - Journal Article
Ulrych, Jaromír - Jelínek, E. - Řanda, Zdeněk - Lloyd, F. E. - Balogh, K. - Hegner, E. - Novák, Jiří Karel
Geochemical characteristics of the high- and low-Ti basaltic rocks from the uplifted shoulder of the Ohře (Eger) Rift, Western Bohemia.
Chemie der Erde-Geochemistry. Roč. 70, č. 4 (2010), s. 319-333. ISSN 0009-2819. E-ISSN 1611-5864
R&D Projects: GA AV ČR IAA300130706
Institutional research plan: CEZ:AV0Z30130516; CEZ:AV0Z10480505
Keywords : Bohemian Massif * Ohře Rift * Eger Rift * Krušné hory Mts. * Erzgebirge * Cenozoic volcanism * high-Ti basaltic rocks * geochemistry
Subject RIV: DB - Geology ; Mineralogy
Impact factor: 1.525, year: 2010

High-Ti melanephelinite, medium-(phono)tephrite, and low-Ti basanite are specific rock types in the Cenozoic Volcanic Province. A contrasting melanephelinite to (phono)tephrite series occurs in the Loučná–Oberwiesenthal Volcanic Centre associated with basanites on the SW periphery of the Krušné hory. The volcanic rocks intrude the Variscan basement of the uplifted shoulder of the Ohře/Eger Rift. Low Mg and Cr, Ni contents and enrichment of incompatible elements in the high-Ti melanephelinites contrast with the composition of primitive low-Ti basanites displaying high Mg and high contents of compatible elements. The large variation in initial strontium isotope ratios of high-Ti melanephelinites at similar epsilon Nd values is interpreted as evidence for melting of metasomatized lithospheric mantle sources comprising K-bearing phases with radiogenic Sr. The initial isotope ratios of all samples are consistent with HIMU-mantle sources and contributions from lithospheric mantle.
Permanent Link: http://hdl.handle.net/11104/0190141