Iron No. 1-4; Shaft Creek Copper Prospects, Hyder Mining District, Prince of Wales-Hyder Census Area, Alaska, USAi

Regional Level Types
Iron No. 1-4; Shaft Creek Copper Prospects	Group of Prospects
Hyder Mining District	Mining District
Prince of Wales-Hyder Census Area	Census Area
Alaska	State
USA	Country

Location: This site consists of a 0.6-mile-long, north-northeast-trending line of prospects in Section 1 between elevations 2600-3250 feet on the divide between Skookum and Fish Creeks (Maas and others, 1995, p. 252 and fig. 66). The above coordinates are for the approximate center of this line of prospects, all of which are within a half-mile of the map location.
Geology: The country rocks in the general area of this site are pelitic metasedimentary and subordinate andesitic metavolcanic (greenstone) strata of the Jurassic or older Mesozoic Hazelton Group; the Triassic Texas Creek Granodiorite, which underlies and locally intrudes the Hazelton; 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). Maas and others (1995, p. 252, 260) describe the deposits as veins, disseminations, and masses of gold-bearing pyrrhotite with associated chalcopyrite and arsenopyrite, and local sphalerite and galena. Individual mineralized zones range from about 60-450 feet wide and are located near or in shears in Hazelton volcanic rocks (greenstone). The prospects roughly align with the contact between Hazelton volcanics and Texas Creek Granodiorite, and are never more than about 1300 feet in lateral distance from the surface exposure of that contact. Maas and others (p. 252) suggest that the age of the deposits is Jurassic, based on similarities in mineralogy, structural setting, and hostrock, with isotopically-dated Jurassic deposits nearby in the Hyder district (for example, see BC065, 067), and at the Scottie gold mine nearby in British Columbia (Alldrick, 1993). If so, the deposits are contemporaneous, at least in part, with island-arc volcanism in Hazelton time (Alldrick, 1993).
Workings: The prospects have been explored by small pits and trenches; there is a flooded shaft on Shaft Creek Copper prospect. Various samples of the deposits collected by the U. S. Bureau of Mines in 1992 or 1993 (Maas and others, 1995. p. 260) contain up to 14.74 ppm Au (Iron No. 2), 64.11 ppm Ag (Iron No. 4), 17.3% Cu (Shaft Creek Copper), 6370 ppm Pb (Iron No. 4), and 6840 ppm Zn (Iron No. 4).
Age: Maas and others (1995, p. 252) suggest that the age of the deposits is Jurassic, based on similarities in mineralogy, structural setting, and hostrock, with isotopically-dated Jurassic deposits nearby in the Hyder district (for example, see BC065, 067), and at the Scottie gold mine nearby in British Columbia (Alldrick, 1993). If so, the deposits are contemporaneous, at least in part, with island-arc volcanism in Hazelton time (Alldrick, 1993).
Alteration: Volcanic (greenstone) hostrocks are impregnated with sulfide minerals.
Production: Small amount of ore stored at Shaft Creek Copper prospect.

Commodities (Major) - Ag, Au, Cu
Development Status: Yes; small
Deposit Model: Polymetallic veins

Other Databases

Link to USGS - Alaska:	BC087

Other Regions, Features and Areas containing this locality

References