Podrobnosti záznamu

Název
    The Variscan Kasperske Hory orogenic gold deposit, Bohemian Massif, Czech Republic
Autor
    Goliáš, Viktor
    Mihaljevič, Martin
    Pudilová, Marta
    Strnad, Ladislav
Jazyk
    anglicky
Typ dokumentu
    článek v periodiku
Zdrojový dokument - seriál
    Ore Geology Reviews
Svazek/č.
    Roč. 48, č. OCTOBER
Strany
    14
Rok
    2012
Výraz tezauru
    Bohemian Massif
    decompression
    Gold
    inclusion
    mineralisation
    vein
Klíčové slovo
    Bohemian
    Czech
    Deposit
    Gold
    Hory
    Kasperske
    Massif
    Orogenic
    Republic
    Variscan
Abstrakt (anglicky)
   Kasperske Hory, one of the largest gold deposits in the Bohemian Massif, is characterised by shear zone-related gold-bearing quartz veins at the tectonic boundary of the two metamorphic terranes of the Moldanubian Unit. Studies of the geology, mineral paragenesis, fluid inclusions and oxygen geothermometry have been carried out to determine the mineralisation events and alternative P-T-t model of this deposit. The pre-mineralisation stage is characterised by geochemical evidence of pegmatites (similar to 700 C and 1.1-0.45 GPa) and metamorphic structures resulting from deformation Dx+1 at the regional metamorphic peak (650 degrees C and 0.5 GPa). The mineralisation in Dx+2 began to develop from the formation of the Q(1) and Q(2) quartz veins (Stage I) under brittle-ductile conditions with the N-S extension; these quartz veins were filled mainly by apatite, plagioclase-1, muscovite and arsenopyrite-1. Revised and reinterpreted gechronological data indicate that the earliest quartz veins
    can be dated at 344 Ma. The Q(3) veins were formed later under brittle to brittle-ductile conditions with crystallisation of plagioclase-2, arsenopyrite-2, scheelite, chlorite, pyrite and calcite (Stage II). The corresponding fluids of Stages land II belong to the C-H-O-N system. The P-T conditions correspond to 590-520 degrees C and to 0.44-0.25 GPa for Stage I and 480-390 degrees C and similar to 0.2 GPa for Stage II. Stage III is characterised by the precipitation of younger quartz, chlorite, molybdenite, calcite, pyrrhotite-1, galena-1, native gold, bismuth, and other Bi-Te minerals; the associated aqueous fluids (salinity 1.5, 8 wt.% NaCI equiv.) follow fluid inclusion trails and were trapped at relatively low pressures and temperatures (290-180 degrees C and <0.1 GPa). Stage IV is mainly dominated by carbonate and fluorite fillings of the open fractures and cracks. Arsenopyrite-1 and -2 and molybdenite are the main gold-bearing and gold-carrying ore phases at this deposit.
Přispěvatel
    UK Praha, Přírodovědecká fakulta
Kód přispěvatele
    UK, PřF
Zdrojový formát
    R
Datum importu
    27. 4. 2014