Stibnite Creek

Mine, Active

Alternative names

Tok Antimony
Stibnite
A Lucky Leak
Gamblin
Caulk

Commodities and mineralogy

Main commodities Au; Sb
Ore minerals pyrite; stibnite
Gangue minerals calcite; muscovite; quartz

Geographic location

Quadrangle map, 1:250,000-scale TC
Quadrangle map, 1:63,360-scale A-6
Latitude 63.2484
Longitude -143.7959
Nearby scientific data Find additional scientific data near this location
Location and accuracy The Stibnite Creek deposit is about 1.5 mile upstream from the mouth of Stibnite Creek, a tributary to the Tok River. It is about 0.5 mile south of the center of section 13, T. 17 N., R. 8 E., of the Copper River Meridian. The location is accurate.

Geologic setting

Geologic description

The Tok Antimony deposit, also called Boulder Creek, Stibnite, A Lucky Leak, and Stibnite Creek, was discovered in the early 1900s. A 12-foot adit was driven in 1914. In 1940, several tons of ore from the prospect were stockpiled by Boulder Creek awaiting transport. All of it was washed away by the river and was never processed (Ebbley and Wright, 1948). There was some mining from an open cut with a bulldozer in 1976 (York, 1980).
Stibnite Creek is one of several similar deposits in a mineral belt about 4 miles long that is called the Tushtena project by the current (2010) operator, Triton Gold Ltd. (Newkirk and others, 1986; DiMarchi and others, 1987; Fonseca, 2009). Work along the belt began in 1976 when Resource Associates of Alaska began geochemical sampling in the area. They soon staked claims over the Discovery Zone prospect (TC034) at the north end of the belt in what then was classified as massive-sulfide mineralization. Their work continued through 1987 in conjunction with several partners and consisted of geologic mapping, rock and soil sampling, and geophysical surveys along what became a belt of deposits. They drilled 17 holes along the belt in 1986 and 8 holes in 1987, totaling 3,390 meters. From 1998 to 2001, Inmet Mining Corporation and Pacific Northwest Resources Company did addition mapping, rock and soil surveys, and they drilled 8 more diamond drill holes totaling 1,489 meters. Two of these holes were drilled at the Stibnite Creek Mine at what is now the south end of the belt. The property was idle until 2007 when James DeMarchi staked 40 claims over the belt and transferred them to Tushtena Resources Ltd. In 2008, they entered into a joint agreement with Triton Gold.
The rocks along the belt consist of two main units: the Devonian to Precambrian, Macomb Belt unit to the east and the Devonian Tushtena Pass unit to the west. They are separated by the Itra Fault, a regional scale, shallowly to moderately dipping thrust fault (Newkirk and others, 1986; DiMarchi and others, 1987; Fonseca, 2009). The Macomb Belt rocks consist mainly of felsic metatuff and volcaniclastic rocks, and sericite-carbonate-quartz phyllonite. The Tushtena Pass unit consists of schist and phyllite, metadiorite, and lithic tuff.
There are two main styles of mineralization along the belt: 1) hanging-wall, bonanza-style vein systems; and 2) footwall, sulfide stockwork and breccia vein systems. The hanging-wall, vein-type mineralization has an arsenic-lead-zinc association with narrow or no alteration envelopes and is characterized by quartz-carbonate-sulfide-gold-mica veins. The footwall, stockwork-breccia zones have a gold-rich core and peripheral antimony-rich mineralization. The deposits are correlative with others along the Tintina gold belt; the key characteristics are the low angle faults that trap the mineralization and the carbonaceous rocks that provide the right chemistry for deposition.
The mineralization at the Stibnite Creek Mine consists of quartz-stibnite-arsenopyrite veins and breccias along a shear zone that is probably part of a series of en echelon structures that splay off the Itra Fault (DiMarchi and others, 1987; Fonseca, 2009; Newkirk and others, 1986; York, 1980). The mineralization is in schist, gneiss and mylonite of the Macomb Belt. The host rocks are pervasively but variably altered to ankerite; this alteration is probably related to the Itra fault, not to the mineralization. The gold-bearing veins have narrow envelopes of sericitic alteration and silicification. Four types of veins occur at the Stibnite Creek Mine: 1) quartz-chlorite+/-sericite fracture fillings; 2) barren ankerite+/- quartz veinlets unrelated to the gold mineralization; 3) barren, white, drusy quartz stockworks; and 4) quartz-stibnite-pyrite+/- arsenopyrite veins that locally contain masses of crystalline stibnite. Two holes were drilled on the Stibnite Creek prospect; the best interval was 4.1 feet that contained 700 parts per billion gold, 2,260 parts per million (ppm) arsenic, and 7.40 ppm silver.
Geologic map unit (-143.798142292097, 63.2480324102475)
Mineral deposit model Tintina Belt-style, gold-arsenopyrite-stibnite quartz vein.
Age of mineralization About 70 to 105 Ma by analogy if Tintina Belt-style mineralization.
Alteration of deposit Ankeritic and sericitic alteration; silicification.

Production and reserves

Workings or exploration
The Tok Antimony deposit, also called Boulder Creek, Stibnite, A Lucky Leak, and Stibnite Creek, was discovered in the early 1900s. A 12-foot adit was driven in 1914. In 1940, several tons of ore from the prospect were stockpiled by Boulder Creek awaiting transport. All of it was washed away by the river and was never processed (Ebbley and Wright, 1948). There was some mining from an open cut with a bulldozer in 1976 (York, 1980).
Stibnite Creek is one of several similar deposits in a mineral belt about 4 miles long that is called the Tushtena project by the current (2010) operator, Triton Gold Ltd. (Newkirk and others, 1986; DiMarchi and others, 1987; Fonseca, 2009). Work along the belt began in 1976 when Resource Associates of Alaska began geochemical sampling in the area. They soon staked claims over the Discovery Zone prospect (TC034) at the north end of the belt in what then was classified as massive-sulfide mineralization. Their work continued through 1987 in conjunction with several partners and consisted of geologic mapping, rock and soil sampling, and geophysical surveys along what became a belt of deposits. They drilled 17 holes along the belt in 1986 and 8 holes in 1987, totaling 3,390 meters. From 1998 to 2001, Inmet Mining Corporation and Pacific Northwest Resources Company did addition mapping, rock and soil surveys, and they drilled 8 more diamond drill holes totaling 1,489 meters. Two of these holes were drilled at the Stibnite Creek Mine at what is now the south end of the belt. The property was idle until 2007 when James DeMarchi staked 40 claims over the belt and transferred them to Tushtena Resources Ltd. In 2008, they entered into a joint agreement with Triton Gold.
Indication of production Yes; small
Reserve estimates None.
Production notes Several tons of high grade ore were stockpiled at the site in 1940, but were washed away by the river before it could be transported (Ebbley and Wright, 1948). There was some mining from an open cut with a bulldozer in 1976; the amount of production, if any, is uncertain (York, 1980).

References

MRDS Number A012543

References

DiMarchi, J.J., Oreskes, N., Newkirk, S.R. and Hanneman, N.L., 1987. AR/TRIO 1987 Annual Report.
Fonseca, Anna, 2009, Technical report on the Tushtena gold property, Delta Mineral District, Alaska: Technical Report for Triton Gold Limited, 67 p. (as of Feb 1, 2010, posted on the Internet at: http://www.tritongold.com.au/docs/Alaskan_Project_Independent_Geologists_Report.pdf).
Newkirk, S. R., Muntzert, J. K., Puchner, C. C., Hanneman, N. L., and Flanders, R. W., 1986, AR JV 1986 Annual Report - Volume 1. Resource Associates of Alaska Inc. Internal Report, 141 p
Resource Associates of Alaska Inc. Internal Report, 111 p.
York, T.M., 1980, Geology of the Tok antimony mine, Tok, Alaska: Golden, Colorado School of Mines, M.Sc. thesis, 94 p.
Reporters C.E. Cameron (ADGGS); D.J. Grybeck (Contractor, U.S. Geological Survey)
Last report date 4/2/2010