Mesozoic magmatism and timing of epigenetic Pb-Zn-Ag mineralization in the western Fortymile mining district, east-central Alaska: Zircon U-Pb geochronology, whole-rock geochemistry, and Pb isotopes - Dusel-Bacon, Cynthia; Aleinkoff, J.N.; Day, W.; Mortensen, J.K. (Geosphere, 2015)