Podrobnosti záznamu

Název
    Gold-tourmaline assemblage in a Witwatersrand-like gold deposit, Ouro Fino, Quadrilátero Ferrífero of Minas Gerais, Brazil: the composition of gold and metallogenic implications
Autor
    Brunetto, Wilson
    Cabral, Alexandre
    Koglin, Nikola
    Vymazalová, Anna
Jazyk
    anglicky
Typ dokumentu
    článek v periodiku
Zdrojový dokument - seriál
    Neues Jahrbuch für Mineralogie. Abhandlungen
Svazek/č.
    Roč. 189, č. 3
Strany
    11
Rok
    2012
Výraz tezauru
    gold, tourmaline, mercury, Ouro Fino, Moeda Formation, Quadrilátero Ferrífero
Klíčové slovo
    Assemblage
    Brazil
    Composition
    Deposit
    Ferrífero
    Fino
    Gerais
    Gold
    Gold-tourmaline
    Implications
    Metallogenic
    Minas
    Ouro
    Quadrilátero
    Witwatersrand-like
Abstrakt (anglicky)
   Ouro Fino, a Witwatersrand-like gold deposit in the Moeda Formation of the Minas Supergroup, Quadrilátero Ferrífero of Minas Gerais, Brazil, has visible gold lacking coeval sulfi de minerals. The visible gold is characteristically intergrown with tourmaline. The gold-tourmaline aggregates truncate sub- to euhedral pyrite, which is epigenetic because it occurs as overgrowths on rounded pyrite that is regarded as detrital. Hence the gold is hydrothermal in origin. Compositionally, the gold is argentiferous, with mercury contents between about 2 and 6 wt.%. Palladium and platinum are insignifi cant (1 ?g/g) in the gold. The mercury component in the gold and the gold-tourmaline assemblage suggest precipitation from boron-rich brines poor in sulfi de sulfur. In the metallogenic context of the Quadrilátero Ferrífero, the gold-tourmaline assemblage of the Moeda Formation can be understood as a reducing equivalent of the mercury-bearing, sulfi de-poor hydrothermal overprint on relatively more
   oxidised rocks of the overlying Itabira Group.
Přispěvatel
    Česká geologická služba
Kód přispěvatele
    ČGS (RIV)
Zdrojový formát
    R
Datum importu
    15. 10. 2014