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