New potassium-argon data on the age of mineralization and metamorphism in the Willow Creek mining district, southern Talkeetna Mountains, Alaska

The now largely abandoned Willow Creek mining district, southern Talkeetna Mountains, Alaska, produced nearly \$18,000,000 in gold and minor silver between 1909 and the early 1950's. Mineralized quartz veins, which contain gold and silver along with minor quantities of base metals (in pyrite, galena, chalcopyrite, sphalerite, molybdenite, and arsenopyrite), cut Late Cretaceous and early Tertiary tonalite and quartzmica schist of probable Jurassic age (Ray, 1954; Silberman and others, 1976; Bela Csejtey, Jr., unpub. data, 1978).