40Ar/39Ar ages from the Tyonek D-6 quadrangle and parts of Tyonek D-7, Tyonek D-5 and Tyonek C-6 quadrangles, Alaska
40Ar/39Ar data from plutonic and volcanic samples collected during preliminary mapping of the Tyonek D-6 and parts of Tyonek D-5, D-7 and C-6 quadrangles yield results indicating three discrete igneous events at about 55, 60 and 68 Ma. Igneous clasts from a boulder conglomerate retain Early Cretaceous ages.