Publisher © Czech Geological Survey, ISSN: 2336-5757 (online), 0514-8057 (print)
Melanite Ti-garnets of the North-Bohemian Cenozoic volcanics
AbstractNorth Bohemian Cenozoic volcanics locally contain garnet as a minor constituent. These volcanics occur in three areas: the central part of the Krušné hory Mts., the surroundings of Ústí nad Labem and the Česká Lípa district, while western as well as eastern flanks of the Cenozoic volcanic strip are entirely devoid of them. Majority of these garnet-bearing rocks corresponds to phonolites but some more mafic rocks (trachybasalt and nephelinite) are also present. In all cases, the garnet has a high Ti-content classifying it as Ti-andradite to schorlomite. Physical parameters (refractive index, density and unit-cell parameter) and major, minor and trace element compositions are given and the origin of garnets is discussed.