The K-Ar age of biotite from the granodiorite stocks is 40.0 m.y., of muscovite from sulfide ore 34.5 m.y., and of adularia from late hydrothermal veins 38.0 m.y., all + or -2 m.y. Rb-Sr values lie on a single isochron with an age of 41.0 m.y. These results suggest a maximum interval of 3 m.y. between granodiorite emplacement and mineralization. Initial value of Sr-87/Sr-86 is 0.705+ or -0.001 for granodiorite stocks, muscovite from sulfide ore, and late albite-adularia mixtures. A genetic association between intrusive rocks and hydrothermal minerals is inferred.

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