Pioneer Mine, Fairbanks Mining District, Fairbanks North Star Borough, Alaska, USAi

Regional Level Types
Pioneer Mine	Mine
Fairbanks Mining District	Mining District
Fairbanks North Star Borough	Borough
Alaska	State
USA	Country

Angus McDougall conducted the first exploration in the vicinity of the Pioneer mine beginning in 1904 (Times Publishing Company, 1912). He and his partners Julius Hoffman, Mr. McGowan and Mr. Clark, eventually staked the Pioneer group which consisted of the War Eagle, Leroy, Pioneer, Iron Mask and Black Warrior claims (Times Publishing Company, 1912). The adjacent Willie claim was staked in 1909 by Lawrence J. McCarty. By 1910 the Willie claim was owned by Frank Lawson and Lawrence McCarty and an unspecified amount of ore had been custom milled from the prospect (Brooks, 1910). In the winter of 1910, shaft sinking was begun on the Willie claim by Lawrence McCarty's sons, Lawrence Junior, age 9 and Willie, age 7. The two boys were assisted by their older sister who acted as surface superintendent (Times Publishing Company, 1912).
Location: The Pioneer mine is located on the divide between Fairbanks Creek and Wolf Creek along the old Circle-Fairbanks trail; SE1/4SW1/4 sec. 21, T. 3 N., R. 2 E., of the Fairbanks Meridian. This site consists of several claims: War Eagle, Leroy, Pioneer, Iron Mask, Black Warrior and Willie. Most production came from the Pioneer claim.
Geology: This site consists of several claims containing gold-bearing quartz shear zones; these are the Pioneer, Willie, Iron Mask, War Eagle, Leroy and Black Warrior claims. Most production came from the Pioneer claim. The Pioneer shaft and prospect pits exposed a shear zone of over 800 feet in strike length. By 1912, $22,000 worth of gold (1,064 ounces) of ore had been mined; the average width of the vein was 34 inches, and the average grade was 2.2 ounces of gold per ton. The highest value was obtained from a 22 ton shipment to the Chena mill which returned an average of $180 gold per ton (8.7 ounces of gold per ton) (Times Publishing Company, 1912). By 1916, two shafts had been sunk on the Pioneer claim on an 18-inch-thick antimony-bearing shear zone oriented N 85 E, 80 N. (Mertie, 1918). Five hundred feet west of the antimony-bearing zone, three gold-bearing quartz stockwork shears were exposed. Two of these zones ranged from 12- to 14-inches-thick and were oriented N 35-45 E, 60-80 NW. The third zone had an east-west strike and a dip of 45 S. These exposures averaged about $10 gold per ton or 0.5 ounces of gold per ton (Mertie, 1918). The Willie claim contained a 4- to 5-foot-wide iron-oxide-stained quartz stockwork zone oriented N 50 E, 80 SE (Prindle, 1910). Free gold could be panned from its 1,000 foot strike length. Shaft sinking in 1910 revealed a 10-inch-thick high grade portion of the shear zone. The Iron Mask claim contained an eight-foot-wide mineralized shear zone oriented east-west and dipping 65 S. A 50-foot shaft had been sunk on this claim by late 1912 and the ore averaged $25 gold per ton or 1.2 ounces of gold per ton (Times Publishing Company, 1912). A three-foot-wide, high grade zone was also exposed on the Iron Mask claim. This zone has a hanging wall consisting of a bleached white decomposed rock believed to be a fine-grained intrusive (Smith, 1913; B 525). The gold-bearing portion of the lode is in fault contact with the decomposed intrusive rock. On the Iron Mask claim, an 8-inch-thick stibnite-bearing shear had been exposed which strikes N 80 W and dips 75 SW. Farther to the east but still on the Iron Mask claim, a 4-foot-thick shear zone carrying low grade gold and stibnite mineralization was exposed and traced into Fairbanks Creek. At the War Eagle claim, visible gold was found in two separate zones which average 1 to 2 feet wide (Smith, 1913; B 525). In the Leroy claim, the high grade portion of the shear averaged 1 foot wide (Smith, 1913; B 525). The farthest east claim, the Black Warrior, contained test pits that exposed high grade gold-quartz shear zones which averaged 8 to 10 inches wide. The average fineness of the Pioneer group gold through 1912 was 814.5 (Smith, 1913; B 525).
Workings: Exploration began in 1904, and the Pioneer group of claims were eventually staked; these included the War Eagle, Leroy, Pioneer, Iron Mask and Black Warrior claims (Times Publishing Company, 1912). The adjacent Willie claim was staked in 1909. In the winter of 1910, shaft sinking was begun on the Willie claim. By 1912, the Pioneer shaft had been sunk to a depth of 120 feet and two other shafts sunk to depths of 49 and 85 feet. Additional prospect pits have exposed the shear zone over 800 feet along strike. In early 1912, a 50-foot-shaft was sunk on the Iron Mask claim. By mid-1912, the western-most claim of the Pioneer group, the War Eagle claim, had been traced in several 8- to 10-foot deep pits (Smith, 1913; B 525). On the Leroy claim, two shafts were sunk on one of the leads that was exposed on the War Eagle claim. Development work on the Pioneer claim included about 200 feet of drifts to the east and west at the 110 foot level (Smith, 1913; B 525). Fifty feet of drift had been completed from the 75-foot level in the next shaft to the east and still further east, a 38-foot-deep shaft had been sunk. The farthest east claim of the Pioneer group, the Black Warrior claim, contained test pits 12- to 15-feet deep every 50 feet over 400 to 500 feet along strike. By 1916, two shafts had been sunk on the Pioneer claim on an inch-thick antimony-bearing shear zone (Mertie, 1918). In 1951, dozer trenching at the Pioneer Group exposed the tops of the old drifts on the antimony shear zone (Saunders, 1960; ATDM MR 49-4, p.2). A shaft was sunk an additional 20 feet to determine if high grade stibnite mineralization was present (Saunders, 1960; ATDM MR 49-4, p.2). In 1969, the Pioneer group of claims were examined by dozer trenching and rotary dirlling. Active exploration of the Pioneer mine area was conducted by Placid Oil in 1984 and 1985 when 2,154.7 feet of diamond core hole was drilled in 13 holes in the Pioneer and Pennsylvania mine site areas (Porterfield and Croff, 1986). In 1988, BP Minerals conducted reverse circulation drilling in the Pioneer mine area (Freeman, 1992).
Alteration: Yellowish oxidation products of stibnite common in quartz.
Production: Production from the Pioneer mine through 1931 was estimated at $14,000 (677 ounces). This production was primarily derived from above the 50-foot level of the main shaft (Hill, 1933).

Commodities (Major) - Au; (Minor) - Sb
Development Status: Yes; small
Deposit Model: Gold and stibnite in quartz shear zones.

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Link to USGS - Alaska:	LG155

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References