Pioneer

Mine, Active

Commodities and mineralogy

Main commodities Au
Other commodities Sb
Ore minerals gold; stibnite
Gangue minerals quartz

Geographic location

Quadrangle map, 1:250,000-scale LG
Quadrangle map, 1:63,360-scale A-1
Latitude 65.0676
Longitude -147.3573
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Pioneer Mine is on the divide between Fairbanks Creek and Wolf Creek along the old Circle-Fairbanks trail; it is in the SE1/4SW1/4 sec. 21, T. 3 N., R. 2 E., of the Fairbanks Meridian. The property consists of several claims: the War Eagle, Leroy, Pioneer, Iron Mask, Black Warrior and Willie. Most production came from the Pioneer claim.

Geologic setting

Geologic description

Note: As of 2008, this site and several others in the vicinity are being explored as a single entity by Freegold Ventures Inc. (Freeman, 2008) Considerable new mineralization has been discovered that indicates this is part of a larger mineralized system that is described as a separate ARDF site (LG206).
In 1904, Angus McDougall was the first to prospect in the vicinity of the Pioneer Mine (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 began 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).
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 exposed the shear zone along 800 feet along strike. In early 1912, a 50-foot-shaft was sunk on the Iron Mask claim. By mid-1912, the westernmost claim of the Pioneer group, the War Eagle claim was 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 lodes 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, 1913a). Fifty feet of drift was completed from the 75-foot level in the next shaft to the east, and still further east, a 38-foot-deep shaft was sunk. The farthest east claim of the Pioneer group, the Black Warrior claim was explored by test pits, 12- to 15-feet deep every 50 feet, along 400 to 500 feet of 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-bearing, shear zone (Saunders, 1960). A shaft was sunk an additional 20 feet to determine if high grade stibnite mineralization was present (Saunders, 1960). In 1969, the Pioneer group of claims were examined by dozer trenching and rotary drilling. Placid Oil Company was active in 1984 and 1985 they drilled 2,154.7 feet of core hole at 13 sites near the Pioneer and Pennsylvania mines (Porterfield and Croff, 1986). In 1988, BP Minerals did some reverse-circulation drilling in the Pioneer mine area (Freeman, 1992).
The Pioneer shafts and prospect pits exposed a shear zone that extends for over 800 feet along strike. By 1912, $22,000 worth of gold (1,064 ounces) 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 N85E, 80 N. (Mertie, 1918). Five hundred feet west of the antimony-bearing zone, three gold-bearing quartz stockworks along shear zones were exposed. Two of these zones were from 12- to 14-inches-thick and were oriented N35-45E, 60-80NW. The third zone had an east strike and a dip of 45S. These exposures averaged about $10 gold per ton or 0.5 ounces of gold per ton (Mertie, 1918).
The Willie claim had a 4- to 5-foot-wide iron-oxide-stained quartz stockwork zone oriented N50E, 80SE (Prindle, 1910). Free gold could be panned for 1,000 feet along its strike. 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 that dipped 65S. A 50-foot shaft was sunk on this claim by late 1912 and the ore averaged $25 gold per ton (about 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 of bleached, white, decomposed rock believed to be a fine-grained intrusive (Smith, 1913, B 525, Smith, 1913, B 542). 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 zone was exposed which strikes N80W and dips 75SW. 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 averaged 1 to 2 feet wide (Smith, 1913, B 525). In the Leroy claim, the high grade portion of the shear zone averaged 1 foot wide (Smith, 1913, B 525). The farthest east claim, the Black Warrior, had 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).
Geologic map unit (-147.359748125344, 65.0671780612315)
Mineral deposit model Gold and stibnite in quartz shear zones.
Age of mineralization Probably about 90 Ma based on analogy with similar gold deposits nearby.
Alteration of deposit Yellowish oxidation products of stibnite common in quartz.

Production and reserves

Workings or exploration
In 1904, Angus McDougall was the first to prospect in the vicinity of the Pioneer mine (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).
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 exposed the shear zone along 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 was 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 lodes 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 was completed from the 75-foot level in the next shaft to the east, and still further east, a 38-foot-deep shaft was sunk. The farthest east claim of the Pioneer group, the Black Warrior claim was explored by test pits, 12- to 15-feet deep, every 50 feet along 400 to 500 feet of 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-bearing, shear zone (Saunders, 1960). A shaft was sunk an additional 20 feet to determine if high grade stibnite mineralization was present (Saunders, 1960). In 1969, the Pioneer group of claims were examined by dozer trenching and rotary drilling. In 1984 and 1985, Placid Oil Comp was active in the area and drilled 13 holes near the Pioneer and Pennsylvania Mines that totaled 2,145.7 feet of core. In 1988, BP Minerals did some reverse-circulation drilling in the Pioneer mine area (Freeman, 1992).
Indication of production Yes; small
Production notes Production from the Pioneer mine through 1931 was estimated at $14,000 (677 ounces). This production was primarily from above the 50-foot level of the main shaft (Hill, 1933).

References

MRDS Number A015452

References

Freeman, C.J., 1992, 1991 Golden Summit project final report, volume 2: Historical summary of lode mines and prospects in the Golden Summit project area, Alaska: Avalon Development Corp., 159 p. (Report held by Freegold Recovery Inc. USA, Vancouver, British Columbia.)
Freeman, C.J., 2008, Executive summary report for the Golden Summit project, Fairbanks Mining District, Alaska: Unpublished Technical Report for Freegold Ventures Ltd., 112 p. (posted on www.sedar.com, March 31, 2008).
Times Publishing Company, 1912, Tanana Magazine, Quartz Edition: Fairbanks, Alaska, Times Publishing Company, 76 p.
Reporters C.J. Freeman, J.R. Guidetti Schaefer (Avalon Development Corporation); D.J. Grybeck (Port Ludlow, WA)
Last report date 6/5/2008