Geologic description
The country rocks in the area of this prospect are pelitic metasedimentary and subordinate andesitic (greenstone) metavolcanic strata of the Jurassic or older Mesozoic Hazelton Group, which is underlain and locally intruded by the Triassic Texas Creek Granodiorite; the Eocene Hyder Quartz Monzonite, which intrudes the Hazelton and Texas Creek rocks; and still-younger Tertiary lamprophyre dikes, which cut all the other rocks (Smith, 1973, 1977; Koch, 1996).
The deposit (Buddington, 1925, p. 74; 1929, p. 72-74; Elliott and Koch, 1981, loc. 77) is in Hazelton Group greenstone and slate cut by Triassic and Eocene porphyry dikes. Most of the work (about 550 feet of adit and crosscuts) was done to prospect quartz veins up to 2 feet thick in a sheared and altered porphyry dike with many included layers of slate and greenstone. The shear zone was traced in outcrop for about 750 feet. The porphyry near the veins is impregnated with pyrite, and the quartz contains disseminated sphalerite and lesser amounts of galena, pyrite, and chalcopyrite. Picked surface samples of this lode reportedly were high in Au and Ag; samples from underground were leaner. In the early 1920s (Buddington, 1925, p. 74), one of the owners described this deposit as a quartz body 12 feet wide carrying about 0.19 oz Au and 6 oz Ag per ton. Selected samples of rich stringers in porphyry were said to assay as much as 4.5 oz Au per ton.
Elsewhere on this property a sheared 7- to 10-foot-thick quartz vein in greenstone (?) is cut by a granodiorite porphyry dike. Local shoots in the walls of this vein carry a little disseminated galena, sphalerite, pyrite, and chalcopyrite. Another shear zone in greenstone carried considerable arsenopyrite and a little galena. Despite fairly extensive underground workings on this property, there is no public record of any production. |
