Homestake

Mine, Inactive

Commodities and mineralogy

Main commodities Ag; Au; Cu; Pb; Zn
Ore minerals chalcopyrite; galena; pyrite; sphalerite; tetrahedrite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale BC
Quadrangle map, 1:63,360-scale A-1
Latitude 56.075
Longitude -130.169
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Homestake mine is in Section 7 at about 3500 feet elevation on a south-facing mountainside approximately 0.3 mile east of upper Ibex Creek (Elliott and Koch, 1981, p. 14, loc. 51). The location is probably accurate within a quarter of a mile.

Geologic setting

Geologic description

The country rock in the area of the Homestake mine is Triassic Texas Creek Granodiorite, which regionally underlies and locally intrudes pelitic metasedimentary and subordinate andesitic metavolcanic strata of the Jurassic or older Mesozoic Hazelton Group; and the Eocene Hyder Quartz Monzonite, which intrudes the Hazelton and Texas Creek rocks (Smith, 1977, Koch, 1996).
The deposit consists of a quartz fissure vein 4-5.5 feet thick in Texas Creek Granodiorite (Buddington, 1925, p. 88-89). The vein was traced in outcrop for about 250 feet. The mineralized parts of the vein contain bands of solid sulfide up to 4 feet thick consisting mainly of argentiferous 'steel' galena, accompanied by pyrite, chalcopyrite, and a little sphalerite. The granodiorite hanging wall of the vein contains stringers of tetrahedrite. So-called 'steel' galena resembles augen gneiss with eyes of granulated pyrite in flow-banded galena; this texture indicates that the mineral deposit was subjected to intense stress since its formation (Buddington and Chapin, 1929, p. 320).
A 9.5-ton test shipment of sorted ore sent to a smelter in 1925 contained 50 percent Pb, 0.7 percent Zn, 22.87 oz Ag per ton, and 0.29 oz Au per ton (Buddington, 1929, p. 95; Cobb, 1978, p. 39).
Lead-isotope studies of galena from the Homestake mine (Maas and others, 1929, p. 229-248) indicate that the deposit is Eocene in age, contemporaneous with emplacement of the Hyder Quartz Monzonite.
Geologic map unit (-130.170705281994, 56.0746962901689)
Mineral deposit model Polymetallic veins (Cox and Singer, 1986; model 22c).
Mineral deposit model number 22c
Age of mineralization Lead-isotope studies of galena from the Homestake mine (Maas and others, 1929, p. 229-248) indicate that the deposit is Eocene in age, contemporaneous with emplacement of the Hyder Quartz Monzonite.

Production and reserves

Workings or exploration A 25-foot crosscut adit is reported to have cut the vein 35 feet below its outcrop (Buddington, 1926, p. 53).
Indication of production Yes; small

Additional comments

Property originally staked in 1923.

References