Publication details
Metamorphosed gold deposit from Orlik near Humpolec, Czech Republic
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| Year of publication | 2015 |
| Type | Appeared in Conference without Proceedings |
| MU Faculty or unit | |
| Citation | |
| Description | The paper presents mineralogic considerations about gold ores in the Orlik deposit (Czech Republic). Data have been obtained on samples coming from medieval pit. Studies of sulfidic ores revealed typical pyrrhotite-löllingite-arsenopyrite and gold textures. These aggregates were recently linked to certain conditions of LP/MP-HT metamorphic evolution. Documented textures confirm the premetamorphic origin of gold-bearing ores and serious remobilisation of gold. The conditions of older (~329 Ma) migmatite metamorphism with temperatures up to 730 oC and pressure about 6 kbar were sufficient to decompose premetamorphic gold bearing arsenopyrite and form löllingite-pyrrhotite assemblages with the younger generation of arsenopyrite and gold. Also significant remobilisation of gold and sulfides into wall rock was observed. Consequent periplutonic metamorphosis (~327 Ma) with only 500 oC and 2,5 kbars was too weak to significantly affect sulphidic textures, but might be connected with the the decomposition of maldonite into the gold-bismuth myrmekite structures and secondary Bi-minerals. |