Golden Horn

Mine, Active

Commodities and mineralogy

Main commodities Au; W
Other commodities Ag; As; Hg; Sb
Ore minerals arsenopyrite; chalcopyrite; cinnabar; gold; lead-antimony sulfosalts; scheelite; sphalerite; stibnite
Gangue minerals dolomite; quartz; tourmaline

Geographic location

Quadrangle map, 1:250,000-scale ID
Quadrangle map, 1:63,360-scale B-4
Latitude 62.44718
Longitude -157.92242
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Golden Horn Mine is at an elevation of about 450 feet, about 0.5 mile southeast of Discovery Camp on Otter Creek. It is about 0.6 mile west-northwest of the center of section 12, T. 27 N., R. 47 W., of the Seward Meridian. The location is accurate. Cobb included the Golden Horn with other nearby lode prospects as locality 11 of Cobb (1972 [MF 363]); also described in Cobb (1976 [OFR 76-576]).

Geologic setting

Geologic description

The Golden Horn deposit consists of a set of quartz-sulfide veins that contain free gold, arsenopyrite, chalcopyrite, cinnabar, lead-antimony sulfosalts, stibnite, sphalerite, and scheelite. The veins are in a zone that strikes N20-35E and dips steeply to vertically. The veins occur in irregularly distributed, quartz-filled shear zones in the Black Creek monzodiorite near its contact with shale and sandstone of the Upper Cretaceous, Kuskokwim Group (Mertie, 1936; Bull, 1988; Bundtzen and others, 1992). Secondary biotite in the Black Creek pluton has been dated at 63.0 Ma; this may also be the age of the hydrothermal mineralization as well as the age of emplacement of the intrusion (Bundtzen and others, 1992; Bundtzen and Miller, 1997; Miller, Bundtzen, and Gray, 2005). The system of veins varies from 10 to 100 feet thick and can be traced for about 650 feet along strikes. There are several other similar veins nearby including the Minnie Gulch and Mohawk prospects (Bundtzen and others, 1992).
The Golden Horn deposit was discovered in 1921 by Rasmus Nielson; he sank a 50-foot shaft and drove 200 feet of drifts. Later, John Warren drove a 130-foot shaft. The deposit was mined by the Golden Horn Mining Company of W.E. Dunkle and Pardners Mines of New York in late 1934 and 1935. By 1938, the underground workings totaled about 1,800 feet in four levels of drifts, two shafts, and several crosscuts (Bundtzen and others, 1992). From 1977 to 1981, WGM, Inc., Union Carbide, and others drilled several diamond core and RC holes at the mine (but the total footage is not available). In 1984, Bull (1988) completed a University of Alaska masters thesis on the property based partly on studies of core from previous exploration work. During the 1980s to early 1990s, John Miscovich sluiced the upper zone of the vein system using hydraulic mining techniques and recovered free gold and gold-bearing, sulfide-scheelite concentrates. In 1988, Bundtzen and Miller produced a detailed geologic sketch of the Golden Horn prospect, which had been stripped by John Miscovich for mining purposes, and collected a number of chip-channel samples (Bundtzen and others, 1992). From 1997 to 2000, WGM Inc. carried out exploration work on the property.
From 1922 to 1937, about 2,707 ounces of gold, 2,620 ounces of silver, 9,337 pounds of lead and 518 pounds of zinc were produced from the Golden Horn Mine. Based on examination of published and unpublished surface and subsurface exploration data, Bundtzen and others (1992) estimated that the Gold Horn deposit contained a minimum, inferred resource of 148,000 tons of material that contains 0.35 ounces of gold per ton and 75 ounces of silver per ton.
Geologic map unit (-157.92482196174, 62.4464954759611)
Mineral deposit model Polymetallic vein or Porphyry Au-Cu (Cox and Singer, 1986; models 22c and 20a).
Mineral deposit model number 22c or 20a
Age of mineralization Secondary biotite in the host pluton is 63.0 Ma; this is possibly the age of the mineralization.
Alteration of deposit The alteration in and near the veins is marked by tourmaline and chlorite; abundant secondary biotite in host pluton.

Production and reserves

Workings or exploration
The Golden Horn deposit was discovered in 1921 by Rasmus Nielson; he sank a 50-foot shaft and drove 200 feet of drifts. Later, John Warren drove a 130-foot shaft. The deposit was mined by the Golden Horn Mining Company of W.E. Dunkle and Pardners Mines of New York in late 1934 and 1935. The principal vein averaged about 12 inches thick; it had sufficient grade to sustain a mining width of about 5 feet. The wall rocks of the veins were gold bearing, probably averaging about 0.2 ounce of gold per ton. Some narrow zones contained as much as 45 ounces of gold per ton and hand sorted material shipped to the U.S. Mint contained about 6 ounces of gold per ton. Mining conditions were, however, difficult and the operation did not remain profitable, especially since a 25 percent royalty had to be paid to the owners of the mine (John Miscovich, oral communication, 2002). The ore was not milled before shipping and a stockpile of probably several thousand tons of material remain that contain about an ounce of gold per ton. By 1938, the underground workings totaled about 1,800 feet in four levels of drifts, two shafts, and several crosscuts (Bundtzen and others, 1992).
From 1977 to 1981, WGM, Inc., Union Carbide, and others drilled several diamond core and RC holes at the mine (but the total footage is not available). In 1984, Bull (1988) completed a University of Alaska masters thesis on the property based partly on studies of core from previous exploration work. During the 1980s to early 1990s, John Miscovich sluiced the upper zone of the vein system using hydraulic mining techniques and recovered free gold and gold-bearing, sulfide-scheelite concentrates. In 1988, Bundtzen and Miller produced a detailed geologic sketch of the Golden Horn prospect, which had been stripped by John Miscovich for mining purposes, and collected a number of chip-channel samples (Bundtzen and others, 1992). From 1997 to 2000, WGM Inc. carried out exploration work on the property.
Indication of production Yes
Reserve estimates Based on examination of published and unpublished surface and subsurface exploration data, Bundtzen and others (1992) estimated that the Gold Horn deposit contained a minimum, inferred resource of 148,000 tons of material that contains 0.35 ounces of gold per ton and 75 ounces of silver per ton.
Production notes The richest ore was mined on several underground levels beginning in 1922 and continued intermittently until about 1937. The main period of mining was in 1934 and 1935 by the Golden Horn Mining Co. The last ore shipment was in late 1937 (Maloney, 1962). From 1922 to 1937, about 2,707 ounces of gold, 2,620 ounces of silver, 9,337 pounds of lead and 518 pounds of zinc were produced from the Golden Horn Mine (Bundtzen and others, 1992). Free gold, and auriferous sulfide and scheelite concentrates were recovered and shipped to buyers intermittently from the 1980s to early 1990s by Miscovich Mining Company (John Miscovich oral communication, 1992).

References

References

Bull, K.F., 1988, Genesis of the Golden Horn and related mineralization in the Flat Creek area, Alaska: Fairbanks, University of Alaska M.Sc. thesis, 300 p.
Bundtzen, T.K., Cox, B.C., and Veach, N.C., 1987, Heavy mineral provenance studies in the Iditarod and Innoko districts, western Alaska: Process Mineralogy VII, The Metallurgical Society, p. 221-246.
Reporters T.K. Bundtzen (Pacific Rim Geological Consulting, Inc.), M.L. Miller (U.S. Geological Survey); and C.C. Hawley (Hawley Resource Group)
Last report date 5/21/2003