The Permian-Triassic low sulfidation epithermal Au deposit of Don Sixto, Mendoza

MÁRQUEZ ZAVALÍA M. F.; GALLISKI M. A.; MUGAS LOBOS A. C.; WALLE M.

Revista de la Asociación Geológica Argentina

Imprenta Don Bosco

Lugar: Buenos Aires; Año: 2018 vol. 75 p. 441 - 456

1851-8249

Don Sixto is a 252.7±1.3 Ma low sulfidation epithermal Au deposit located in Mendoza, Argentina. The mineralization in this area (~4km2) reaches a gold resource of 1,258,000 ounces, occurring as Au-quartz veins and Au-dissemination in volcanic-pyroclastic unitsclosely related to the Choiyoi magmatism. Seven stages of mineralization were recognized, where quartz is the major gangue mineralwith lesser adularia and fluorite (± calcite). The most representative vein textures are massive, crustiform, and comb. Bladed quartztogether with adularia (± calcite) were recognized in the stages 2 and 4. Abundant pyrite and lesser arsenopyrite, chalcopyrite andsphalerite were recognized in most stages. Gold has variable fineness and occurs mainly in the stage 4, together with scarce uytenbogaardtite,acanthite and Se- and Te-bearing minerals. Microthermometry data indicate that mineralizing fluids were diluted (