Record details

    Epithermal gold mineralization in Costa Rica, Cordillera de Tilarán - exploration geochemistry and genesis of gold deposits
    Dobeš, Petr
    Lukeš, Petr
    Mixa, Petr
    Quintanilla, Enrique
    Žáček, Vladimír
Publication type
    článek v periodiku
Source title - serial
    Journal of Geosciences
    Roč. 56, č. Spec. iss
Thesaurus term
    gold, epithermal mineralization, fluid inclusion, alteration, Costa Rica, Cordillera de Tilarán
Abstract (in english)
   Epithermal gold mineralization in the NW of Costa Rica is confined to Miocene-Pliocene volcanic arc. Gold-bearing quartz veins are related to steep fracture zones affected by mylonitization and pronounced alteration. Native gold (electrum 30-42 wt. % Ag) occurs as inclusions mostly up to 25 ?m grown in quartz and pyrite. The mineral assemblage includes pyrite, sphalerite, chalcopyrite, arsenopyrite and marcasite. Acanthite, pyrargyrite, greenockite, covellite, bornite and cassiterite are scarce. Sb, As, Pb and Hg exhibit significant positive correlations with Au. Fluid inclusions of the H2O type were found in quartz and sphalerite. The older coarse-grained quartz contains primary H2O inclusions with homogenization temperatures between 182 and 276 °C and very low salinity. Primary H2O inclusions in fine-grained younger quartz exhibit homogenization temperatures from 154 to 220 °C and very low salinity up to 3 wt. % NaCl eq. The age of ore pulses is estimated in the period between c. 6.0
   -2.1 Ma.
    Česká geologická služba
Contributor code
    ČGS (RIV)
Source format
Import date
    15. 10. 2014