Metamorfní původ struktur pyrhotinu, arzenopyritu a löllingitu z Orlíku u Humpolce, Česká republika
Článek v PDFMetamorphic origin of textures of pyrrhotite, arsenopyrite and löllingite from Orlík near Humpolec, Czech Republic
Sulphidic ores with gold were studied at locality Orlík near Humpolec. Origin of typical arsenopyritelöllingite-pyrrhotite assemblages with invisible gold were previously described as result of LP-HT metamorphosis of older gold-bearing sulphidic ores on various localities worldwide. Results from Orlík show typical features of such assemblages and confirm premetamorphic origin of gold-bearing ores. The conditions of older migmatite metamorphism with temperatures up to 730 °C and pressure decreasing from 6 kbar to 2 kbar were sufficient to decompose premetamorphic arsenopyrite and form löllingite-pyrrhotite assemblages with younger generation of arsenopyrite. Subsequent periplutonic etamorphosis was too weak to significantly affect sulphidic textures.
Lenka Losertová, Zbyněk Buřival, Zdeněk Losos, Institute of Geological Sciences, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic. e-mail: lena.los@seznam.cz, zbynek@burival.com, losos@sci.muni.cz
Jiří Litochleb, National Museum – Natural History Museum, Cirkusová 1740, 193 00 Praha 9 – Horní Počernice, Czech Republic. e-mail: jiri_litochleb@nm.cz