Record details

    Geology and genesis of Variscan porphyry-style gold mineralization, Petráčkova hora deposit, Boheian Massif, Czech Republic
Other titles
    Intrusion-Related Gold Systems (Variant.)
    Markey, Richard
    Pertold, Zdeněk
    Pertoldová, Jaroslava
    Pudilová, Marta
    Stein, Holly
    Zachariáš, Jiří
    Žák, Karel, 1957-
Source title - serial
    Mineralium Deposita
    Vol. 36, no. 6
    p. 517-541
    14 obr., 4 fot., 8 tab., 3 s.bibl.
    Zkr. název ser.: Mineralium Depos. (Berlin).
Subject group
    datování Re/Os
    geneze ložiska
    hydrotermální alterace
    inkluze fluidní
    izotopy stabilní
    ložisko porfyrového typu
    rudy Au
    středočeská ostrovní zóna
    středočeský pluton
    vrásnění variské
Geographical name
    Vacíkov-Petráčkova hora (Příbram)
Abstract (in english)
   large numberr of Variscan mesothermal g old deposits are located in the central part of the Bohemian Massif, close to the Central Bohemian Plutonic Complex. The Petráčkova hora deposit has many features that distinguish it from other deposits in the region and suggest its mineralization is closely related to the late magmatic processes associated with the Petráčkova hora granodiorite. The gold ores occur as sheeted arrays of quartz veins and veinlets hosted by the small Petráčkova hora granodiorite stock. Gold is found mainly as free grains of 900 fineness, and is accompanied by abundant pyrrhotite and chalcopyrite, anbd accessory pyrite, arsenopyrite, loellingite, and molybdenite. Molybdenite from the Petráčkova hora deposit has been dated by the Re-Os method at 344.4˝2.8 Ma. Hydrothermal alteration in the Petráčkova hora deposit exhibits a distinct temporal paragenesis. Selectively pervasive, early K-alteration and silicification are the oldest hydrothermal phases.
   These were followed by early quartz veins (Q1 to Q4) that contain most of the gold mineralization. Late quartz veins (Q5) and fracture-controlled silicification are gold-poor or barren. Barren calcite veins are the youngest hydrothermal product. extensive low-temperature meteoric-water dominated alteration, as is typical of classic porphyry deposits, is absent. However, the lower Ű18O whole rock values for Petráčkova hora granodiorite and aplite (+2.4 to +5.1%. SMOW) compared to other intrusions in the region reflect either interaction
    Česká geologická služba
Contributor code
    ČGS (UNM)
Source format
Entered date
    31. 8. 2007
Import date
    8. 8. 2012