Harmotome from the Natural Monument Picrite Amygdaloid Rock near Kojetín (Moravia, Czech Republic)

Article PDF
Acta Mus. Moraviae, Sci. Geol. 100 (2015), issue 1, pages 17–22
Article
Authors:
Abstract:

Harmotome from the Natural Monument Picrite Amygdaloid Rock near Kojetín (Moravia, Czech Republic)

Natural Monument Picrite Amygdaloid Rock near Kojetín (4.5 km SSW from Nový Jičín) presents abandoned quarry and roadcut at the southern end of the village. Outcroping body of volcanic aglomerate is formed by fragments of amygdaloid picrites and trachytic rocks enclosed in younger lava. Xenolites of calcaeous pelites yielded dinoflagelate age of Early Barremian to Barremian/Aptian boundary, which is the age of enclosing sediment of the Silesian Unit of the Outer Western Carpathians. Calcite veinlet containing harmotome was found. Harmotome forms brownish red radial aggregate cca 4 mm in diameter. Its average chemical formula is (Ba1.80Na0.14Ca0.14K0.08Fe0.02)[Al4.75Si11.37Ti0.03O32.00] · 12 H2O. It belongs to the low temperature hydrothermal mineralization, typical for teschenite association rocks.

Contact:

Jakub Jirásek, Institute of Geological Engineering, Faculty of Mining and Geology, Vysoká škola báňská – Technical University of Ostrava, 17. listopadu 15/ 2172, 708 33 Ostrava-Poruba, Czech Republic, e-mail: jakub.jirasek@vsb.cz
Dalibor Matýsek, Institute of Geological Engineering, Faculty of Mining and Geology, Vysoká škola báňská – Technical University of Ostrava, 17. listopadu 15/ 2172, 708 33 Ostrava-Poruba, Czech Republic, e-mail: dalibor.matysek@vsb.cz

Citation:
Jirásek, J., Matýsek, D., 2015: Harmotom z přírodní památky Pikritové mandlovce u Kojetína (Moravia, Česká republika). – Acta Mus. Morav., Sci. Geol., 100, 1, 17–22 (with English summary)
ISSN: 1211–8796