Top (ARDF #BC088) Ag, Au, Zn

Top

Prospect, Undetermined

Commodities and mineralogy

Main commodities	Ag; Au; Zn
Ore minerals	pyrite; sphalerite; tetrahedrite
Gangue minerals	quartz

Geographic location

Quadrangle map, 1:250,000-scale	BC
Quadrangle map, 1:63,360-scale	A-1
Latitude	56.047
Longitude	-130.06
Nearby scientific data	Find additional scientific data near this location
Location and accuracy	The Top prospect is in Section 23 at an elevation of about 1500 feet on the west side of Mineral Hill, 0.3 mile due west of its highest point (Maas and others, 1995, p. 254 and fig. 66). The location is accurate within about 0.1 mile.

Geologic setting

Geologic description The country rocks in the area of the Top prospect are pelitic metasedimentary and subordinate andesitic metavolcanic strata of the Jurassic or older Mesozoic Hazelton Group; the Triassic Texas Creek Granodiorite, which underlies and locally intrudes the Hazelton; and the Eocene Hyder Quartz Monzonite, which intrudes the Hazelton and Texas Creek rocks (Smith, 1977; Koch, 1996). According to Maas and others (1995, p. 254, 258), the deposit consists of disseminated and semi-massive pyrite, sphalerite, and tetrahedrite, and a quartz-sulfide vein. The deposit is hosted in Hazelton volcanic rocks and has been exposed for a length of about 450 feet. Maas and others (p. 254) suggest that this deposit is Jurassic in age, based on similarities in mineralogy, structural setting, and hostrock, to isotopically-dated Jurassic deposits elsewhere in the Hyder district (for example, see BC065, BC067). If so, the deposit is contemporaneous, at least in part, with island-arc volcanism in Hazelton time (Alldrick, 1993).
Geologic map unit	(-130.061704694651, 56.0467043555607)
Mineral deposit model	Polymetallic veins (Cox and Singer, 1986; model 22c).
Mineral deposit model number	22c
Age of mineralization	Maas and others (1995, p. 254) suggest that this deposit is Jurassic in age, based on similarities in mineralogy, structural setting, and hostrock, to isotopically-dated Jurassic deposits elsewhere in the Hyder district (for example, see BC065, BC067). If so, the deposit is contemporaneous, at least in part, with island-arc volcanism in Hazelton time (Alldrick, 1993).
Alteration of deposit	Volcanic hostrocks are impregnated with sulfide minerals.

Production and reserves

Workings or exploration	The deposit has been exposed by surface trenching for about 450 feet. Samples collected by the U.S. Bureau of Mines in 1992 or 1993 (Maas and others, 1995, p. 258) contain up to 48.03 ppm Au, 100.8 ppm Ag, and 10.3 percent Zn.
Indication of production	None

References

References Alldrick, D.J., 1993, Geology and metallogeny of the Stewart mining camp, northwestern British Columbia: British Columbia Department of Mines and Petroleum Resources Bulletin 85, 105 p., 2 plates, scale 1:50,000. 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