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Abstract:The Proterozoic Vazante zinc silicate district in Minas Gerais, Brazil, hosts world-class hypogene willemite deposits in dolomitic rocks interbedded with siliciclastic rocks deposited in subtidal to supratidal environments. Willemite ore bodies are structurally controlled along regional NE-trending structures which are interpreted as being active during the Neoproterozoic Brasiliano orogeny. The hydrothermal alteration is characterized by an early stage of Fe-dolomite, which replaced the host dolomitic rocks, followed by precipitation of minor sphalerite and then hematite and willemite. Elements commonly enriched in the zinc ore include As, Ba, Be, Bi, Cd, Co, Fe, Ge, In, Mo, Ni, Sb, Se, U, V and W. Mineralogical, fluid inclusion and isotopic data indicates that mixing of S-poor metalliferous saline fluids with meteoric water favored the formation of willemite ore. Carbonaceous phyllites from the underlying thick siliciclastic sequence show evidence of early enrichment in zinc (and ore-related metals) and remobilization, respectively, prior to and during the Brasiliano orogenic event. This unit is interpreted as a possible source of ore-related elements. It is proposed that during the Brasiliano orogeny, hot (T > 170 • C) saline fluids (>15 wt % eq. NaCl) leached metals from siliciclastic source rocks and precipitated willemite ore in the overlying dolomitic sequence along structures that favored mixing with oxidizing meteoric water.

Brazil's beer industry has experienced a significant growth over the recent years, driving professionals to seek brewing beer focused on quality aspects. As a result of this movement, the consumer attention to products that highlight the national or local identity has rocketed in recent times, especially Brazilian types of beers, as Catharina Sour. Catharina Sour beer was produced using the traditional method to acidify the wort by lactic fermentation and using a bee pollen, as a newer source of microorganism to produce sour beers. For that, mango and passion fruit were used, including barley and wheat malt, yeast, and hop. Some physicochemical analyses were made according to EBC (European Brewery Convention) guidelines, to raise information about the process and final product. There were close correlations between the physic-chemical, sensory and liquid chromatography analysis, showing that the presence of pollen, and consequently the presence of yeast, acetic acid bacteria and fructophilic lactic acid bacteria (FLABs), can bring different aromas to Catharina Sour beers, showing an excellent potential to use this newer source of microorganisms to produce sour beers.