Dykes and small stocks of alaskite intrude the Nelson granodiorite and quartz diorite (Cretaceous). The Nelson intrusives are also cut by granite porphyries of the Valhalla Complex. These rocks are cut by younger (Eocene/Oligocene) andesitic and dioritic intrusives. Argentiferous and auriferous pyrite, galena, sphalerite, hematite, magnetite, malachite, azuirte, chalcopyrite and fluorite occur in various combinations in quartz veins or silicified zones.