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Cabral Alexandre Raphael Tupinambá Miguel Zeh Armin Lehmann Bernd Wiedenbeck Michael Brauns Michael Kwitko-Ribeiro Rogerio 《Mineralogy and Petrology》2017,111(6):807-819
Mineralogy and Petrology - The platiniferous gold–palladium belt of Minas Gerais, Brazil, forms an approximately 240-km-long, roughly north–south-trending domain that includes numerous... 相似文献
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Alexandre Raphael Cabral Nikola Koglin Harald Strauss Helene Brätz Rogerio Kwitko-Ribeiro 《Mineralium Deposita》2013,48(7):805-816
The distribution of mineral deposits, characterised as barite deposits, hematite-rich auriferous deposits and auriferous tourmaline–sulfide deposits, displays a regional sulfate–hematite–sulfide zoning along the thrust-delineated limbs of the Mariana anticline, in the south-eastern part of the Quadrilátero Ferrífero of Minas Gerais, Brazil. Cross-cut relationships of barite veins and sulfide lodes indicate that sulfidation occurred in a late-tectonic context, which is here attributed to the collapse of the ~0.6-Ga Brasiliano thrust front. Reconnaissance S-isotopic data from barite and pyrite (Antônio Pereira barite deposit and its adjacent gold deposit, respectively), and arsenopyrite (Passagem de Mariana gold deposit), suggest a new interpretation for the hydrothermal fluid overprint in the Mariana anticline. The Antônio Pereira barite has Δ33S values that are near zero, constraining the sulfate source to rocks younger than 2.45 Ga. The barite-δ34S values are between +19.6 and +20.8?‰. The Passagem arsenopyrite and tourmaline have Co/Ni ratios that define a positive linear trend with the Antônio Pereira pyrite. The latter has homogenous δ34S values, between +8.8 and +8.9?‰, which are compatible with thermochemical reduction of aqueous sulfate with the S-isotopic composition of the Antônio Pereira barite. 相似文献
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