Crest (ARDF #BC072) Au, Cu, Pb

Crest

Prospect, Inactive

Commodities and mineralogy

Main commodities	Au; Cu; Pb
Ore minerals	chalcopyrite; galena; pyrite
Gangue minerals	quartz

Geographic location

Quadrangle map, 1:250,000-scale	BC
Quadrangle map, 1:63,360-scale	A-1
Latitude	56.0167
Longitude	-130.063
Nearby scientific data	Find additional scientific data near this location
Location and accuracy	The Crest prospect is in Section 35 at an elevation of about 1150 feet on a west-facing mountainside overlooking Salmon River about 0.5 mile below its confluence with Texas Creek. It is about 0.5 mile southeast of the ruins at Ninemile (Elliott and Koch, 1981, p. 18, loc. 72). The location is accurate within about 0.2 mile. Also see Additional Comments field, below.

Geologic setting

Geologic description The country rock in the area of the Crest prospect is the Triassic Texas Creek Granodiorite, which underlies and locally intrudes pelitic metasedimentary and subordinate andesitic (greenstone) strata of the Jurassic or older Mesozoic Hazelton Group (Smith, 1977; Koch, 1996). The deposit (Buddington, 1929, p. 81-82) is in a thin but persistent fissure zone in granodiorite that has been traced for about 350 feet in opencuts and strippings. The zone contains quartz veins or stringers as much as 3 feet in aggregate thickness that contain shoots of relatively massive galena, accompanied by pyrite and a little chalcopyrite. The granodiorite country rock adjacent to the veins is impregnated with pyrite, which also occurs with galena on fracture surfaces. Some small quartz stringers assayed as much as 5 oz Au per ton, but most are much leaner.
Geologic map unit	(-130.064704431155, 56.0164040497721)
Mineral deposit model	Polymetallic veins (Cox and Singer, 1986; model 22c).
Mineral deposit model number	22c
Alteration of deposit	Granodiorite country rock adjacent to veins is impregnated with sulfides.

Production and reserves

Workings or exploration	Prospect was explored in 1920s by open cuts and stripping. Some sulfide-bearing quartz stringers assayed as high as 5 oz Au per ton, but most are much leaner.
Indication of production	None
Additional comments Property probably originally staked in early 1920s. The Crest (?) claims staked in 1978 (?) are not on the old Crest property (Elliott and Koch, 1981, loc. 72).

References

MRDS Number	A010232
References Smith, J.G., 1977, Geology of the Ketchikan D-1 and Bradfield Canal A-1 quadrangles, Alaska: U.S. Geological Survey Bulletin 1425, 49 p., 1 plate.
Reporters	H. C. Berg (Fullerton, California)
Last report date	5/17/1998