Robinson

Mine, Inactive

Alternative names

Mohawk
Franklin
Rose
Heilig and Creighton

Commodities and mineralogy

Main commodities Au
Other commodities Sb
Ore minerals arsenopyrite; gold; stibnite

Geographic location

Quadrangle map, 1:250,000-scale LG
Quadrangle map, 1:63,360-scale A-1
Latitude 65.048
Longitude -147.473
Nearby scientific data Find additional scientific data near this location
Location and accuracy Cobb (1972, MF-413), loc 29; NE1/4 sec. 35, T. 3 N., R. 1 E., of the Fairbanks Meridian. The Robinson mine is located approximately 3200 feet south of the Newsboy shaft near the power substation on the Pedro Dome access road.

Geologic setting

Geologic description

The Robinson mine contains several quartz veins that contain free gold, stibnite, pyrite, and arsenopyrite. The veins cut gray calcareous quartzites with stockwork quartz. Pyrite and arsenopyrite are the two most abundant disseminated minerals in the wall rocks (Freeman, 1992). The initial 1-foot-wide shear zone, exposed in a 180 foot adit, has a strike of N 10 E with a steep dip to the west. A second shear was discovered near the shaft house. This shear strikes N 70 W, dips vertically, and is 8 inches wide (Chapin, 1914). Another shear zone was intersected west of the 50-foot level of an inclined shaft. This high-grade quartz-rich vein is 16 to 18 inches thick and strikes N 20 E and dips 60 NW. A second shaft, known as the Boyd shaft, was located 75 feet northwest of the Robinson shaft and had been sunk to a depth of 30 feet in 1916. The shear exposed in the Boyd shaft contains abundant arsenopyrite; it is oriented N 80 W, 35 SW.
Dump samples collected from the Robinson prospect in 1986 contained from trace to 4.182 ounces of gold per ton, greater than 1,000 ppm arsenic, minor antimony, and trace levels of silver (Freeman and others, 1986).
Accurate production records for the Robinson mine are not available, however, based on mine maps provided by Charles Lazeration, production is estimated at approximately 5,000 tons of ore (Freeman, 1992).
Geologic map unit (-147.475445820249, 65.0475761566458)
Mineral deposit model Gold, stibnite, sulfide-rich quartz veins.

Production and reserves

Workings or exploration
By 1912, a 180 foot adit had been driven on a 1-foot-wide, quartz-rich shear zone (Smith, 1913; B 525). By 1913, the prospect was being explored by L. Goyett through a 50-foot inclined shaft on a 4-foot-wide shear zone (Chapin, 1914). At the 50-foot level, the shaft becomes vertical for 25 feet, at which point a 20-foot cross-cut was driven to intersect an 8-foot-wide shear zone. A second shaft, known as the Boyd shaft, was located 75 feet northwest of the Robinson shaft and had been sunk to a depth of 30 feet by 1916 (Mertie, 1918). By 1917, the Robinson prospect was known as the Heilig and Creighton mine, and was equipped with a Little Giant mill (Martin, 1919). No new development work had been conducted on the prospect in 1917. Work was continued in 1918 but no production was reported (Martin, 1920). In 1934, the Robinson shaft and Boyd and Shaw shaft were flooded and the open cut between the two shafts filled with debris and water (Spencer and O'Neill, 1934). In 1934, Fred C. Robinson was living on the Robinson prospect but no work had been done on the prospect for several years (Spencer and O'Neill, 1934). In 1938, Fred Robinson cleaned out the Robinson shaft and repaired the mill. The Robinson prospect was examined as a possible source of antimony in 1942, but no additional exploration was recommended due to insufficient potential for significant tonnage (Killeen and Mertie, 1951).
Saarela (1951) reported active mining at the Robinson prospect in 1950 by Vern Jokela and Charles Lazeration. Ore was milled at the Cleary Hill mill. Mr. Lazeration, presently residing in Fairbanks, has provided two mine maps of the Robinson mine which show workings on the 60-, 100- and 200-foot levels from a shaft driven to a depth of approximately 210 feet (Fairbanks Exploration Inc., unpublished report, 1986). Drifts on the 200-foot level had been driven 470 feet along the shear to the northeast and 250 feet to the southwest. A ventilation shaft at the 190 foot station of the southwest drift connects with the surface. At the 470-foot station of the northeast drift on the 200-foot level, a stope had been worked to the 100-foot level and nine ore draw points had been installed and were ready for use. The 100-foot level was driven 470 feet to the northeast and 190 feet to the southwest where a ventilation shaft connected it with the surface. The 100-foot level was mined out over its entire 470-foot length on the northeastern side of the 100-foot level and over its entire 190-foot length on the southwestern side of the shaft. The 60-foot level was mined out over a 90-foot length from the raise to the ventilation shaft connecting the three levels on the southwestern side of the shaft. The Robinson shaft currently is flooded and inaccessible (Freeman, 1992).
Indication of production Yes; small
Production notes
By 1912, a 180-foot adit had been driven on a 1-foot-wide quartz-rich shear zone (Smith, 1913; B 525). Two tons of ore from this adit were custom milled in Fairbanks and produced a large amount of sulfide concentrate and an unspecified amount of gold. By 1916, the prospect was known as the Mohawk prospect and produced 46 tons of ore over a four month period. Work was continued in 1918 but no production was indicated (Martin, 1920). Active mining was being conducted on the Robinson prospect in 1950; the ore was milled at the Cleary Hill mill (Saarela, 1951).
Accurate production records for the Robinson mine are not available, however, based on mine maps provided by Charles Lazeration; the production is estimated at approximately 5,000 tons of ore (Freeman, 1992).

Additional comments

The Robinson mine was previously known as the Creighton mine but was sometimes called the Franklin mine (the owner at one time was Duane Franklin).

References

MRDS Number A015374

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.)
Spencer, W.W., and O'Neill, W.A., 1934, A survey of gold quartz veins on the north flank of Pedro Dome: Fairbanks, University of Alaska, B.S. thesis, 52 p.
Reporters C.J. Freeman, J.R. Guidetti Schaefer (Avalon Development Corporation)
Last report date 5/4/1999