Source of mineralizing components in hydrothermal ore fluids as evidenced by ⁸⁷ Sr/ ⁸⁶ Sr and stable isotope data from the Pasto Bueno deposit, Peru Available to Purchase

Wolframite, tetrahedrite, and base metal sulfides in quartz veins associated with a 10-m.y.-old quartz monzonite stock. ⁸⁷ Sr/ ⁸⁶ Sr of fluid inclusion waters in the host minerals ranges from 0.7058 to 0.7239 with Rb/Sr < or = 0.027. The independent variables delta D and ⁸⁷ Sr/ ⁸⁶ Sr clearly indicate the following: (1) that delineation of the three recognized waters involved in the mineralization process is possible; (2) that wolframite was deposited from magma-derived tungsten in solution when a large (30-50%) meteoric water influx caused precipitation by a concurrent drop in fluid temperature, a decrease in salinity, and an increase in pH and f _O2 of the fluid; (3) that sulfide mineralization was from mixed derivation ore fluids, even though a magmatic source of sulfur is indicated; and (4) that fluorite exclusively is related to fluids deriving both water and solutes from the stock.--Modified journal abstract.