Minerály řady baryt-celestin z vápencového lomu u Nectavy (nectavské krystalinikum, Česká republika)Článek v PDF
Minerals of the baryte-celestine series from the limestone quarry near Nectava (Nectava Crystalline Complex, Czech Republic)
The second occurrence of celestine in Moravia, which was discovered in an abandoned limestone quarry near Nectava, is described in this contribution. The accessory minute inclusions of celestine and ba ryte are present in a calcite vein cutting host (Devonian?) limestone, which belongs to (para)autochthon of the Nectava Crystalline Complex. The chemical composition of sulphate inclu sions varies widely (Brt0.6–97.2Clt1.2–97.6Anh1.6–7.8). The source of Ba and Sr is supposed in the host limestones, whereas the available results suggest episodic remobilization of both metals into the fluids during hydrothermal process. The observed elevated contents of Ca in minerals of the baryte-celestine series are uncommon. They cannot be explained by topomineral influence of host limestones only. Instead, the important role of some genetic parameters (e.g., temperature, pressure, and/or fluid composition) is suggested. The primary Ba mineralization of limestones of (para)autochthon of the Nectava Crystalline Complex could represent an alternative source of Ba for formation of Ba-enriched white micas, which were in places detected during previous research in basal parts of the superposed Nectava orthogneisses.
Zdeněk Dolníček, Department of Mineralogy and Petrology, National Museum, Cirkusová 1740, 193 00 Prague 9-Horní Počernice, e-mail: email@example.com
Michaela Krejčí Kotlánová, Research Institute for Building Materials, Hněvkovského 30/65, 617 00 Brno; Institute of Geological Sciences, Masaryk University, Kotlářská 267/2, 611 37 Brno