0145719 - GLU-S 20033090 RIV CZ eng J - Journal Article
Melka, Karel - Novák, Jiří Karel - Ulrych, Jaromír - Wiesner, T.
Celadonite and saponite nodules from Tertiary volcanic breccia of Račí vrch Hill, České středohoří Mts.
Acta Universitatis Carolinae. Geologica. Roč. 44, - (2000), s. 109-117. ISSN 0001-7132
R&D Projects: GA MK RK99P03OMG035
Institutional research plan: CEZ:AV0Z3013912
Keywords : celadonite * saponite * Ohře Rift
Subject RIV: DB - Geology ; Mineralogy

A small volcano of the Račí vrch Hill near Krásné Březno has erupted basaltic volcanic breccia and a columnar basanitic neck (26.7 Ma in age). This locality is attractive for conspicuous green-coloured clay mineral nodules, 1-7 cm in size, and for aragonite crystals hosting in volcanic breccia. Spongy textured celadonite (1M polytype with well ordered structure), Fe-rich saponite with a subordinate mixed-layer phase of the celadonite/smectite series were identified as replacements after mantle xenoliths containing altered olivine, ferromagnesian minerals, and volcanic glass. As concluded in the discussion, any geological environment cannot be the only criterion for the differentiation of celadonite, Al-rich celadonite and glauconite.
Permanent Link: http://hdl.handle.net/11104/0043274