Mineralogy, fluid inclusion, and stable isotope constraints on the genesis of the Roudny Au-Ag deposit, Bohemian Massif

Abstract

Geochemical and mineralogical study of ore and gangue minerals from the Roudny Au-Ag deposit identified three main mineralization stages differing in temperatures (400-330, 350-250, 250-70 °C) and in composition of parental fluids (from early low-salinity H2O-CO2 +/- CH4-N2 fluids with isotopic signature of metamorphic fluids to low-salinity aqueous fluids with significant admixture of meteoric fluids. Possible ages of electrum mineralization (cca 300 to 275 Ma) and Ag-Pb-Zn vein-type mineralization (cca 275 to 265 Ma) are discussed.

Overall, the Roudny deposit shows striking similarities with 300 Ma gold deposits of the French Massif Central.

Keywords

• fluid inclusions
• stable isotopes
• Au-Ag
• orogenic gold deposit
• Bohemian Massif
• electrum
• arsenopyprit