Hoggatt Creek

Prospect, Active

Commodities and mineralogy

Main commodities Au
Ore minerals pyrite
Gangue minerals calcite; quartz

Geographic location

Quadrangle map, 1:250,000-scale JU
Quadrangle map, 1:63,360-scale D-4
Latitude 58.8322
Longitude -135.0267
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is at an elevation of about 500 feet on Hoggatt Creek, a informally-named north tributary to Johnson Creek. It is 1.5 miles northwest of Berners Bay and 1 mile southeast of the Jualin Mine (JU044), in the SW1/4 section 14, T. 35 S., R. 62 E. of the Copper River Meridian. The location is accurate.

Geologic setting

Geologic description

Note: Beginning in the 1990s, this and other old mines and prospects in the vicinity were consolidated by Coeur-Alaska into a single property (Birak, 2006). They have carried out major new drilling and underground exploration that better defines the mineralization, largely blurs the geologic distinction among the old deposits, and extends the ore bodies greatly. They have developed a coherent modern interpretation of the mineralization as a single deposit which Coeur-Alaska intends to mine as a unit. This deposit is described separately in ARDF as the Jualin (Coeur-Alaska) deposit (JU262). For geologic reference purposes and for their historic value, the pre-Coeur-Alaska data for this and the other old mines and prospects that Coeur-Alaska consolidated are retained in ARDF.
The Hoggatt Creek deposit was probably discovered around 1895 but little work has been done since. Workings include a 22-foot adit, 2 open cuts, and several trenches. The deposit consists of a concordant quartz vein that cuts metavolcanic greenschist and Jualin Diorite. The vein strikes SE and dips 65-75SW; it has been traced in outcrop for at least 600 feet and is from a few inches to 4 feet thick. The vein contains 1 percent to 7 percent pyrite. Samples averaged 268 parts per million (ppm) copper and 0.4 ppm gold (Redman and others, 1989).
Geologic map unit (-135.028509883399, 58.8318735209303)
Mineral deposit model Low-sulfide Au-quartz vein (Cox and Singer, 1986; model 36a).
Mineral deposit model number 36a
Age of mineralization Hydrothermal muscovite from veins in the Jualin mine are 53.2 Ma to 55.5 Ma (Miller and others, 1994). This coincides with the 55 Ma age of the other mesothermal gold veins in the Juneau Gold Belt (Goldfarb and others, 1997).

Production and reserves

Workings or exploration There is a 22-foot adit, 2 open cuts, and several trenches; all probably date to before 1900.
Indication of production None

References

References

Birak, D.J., 2006, Kensington gold project: Unpublished Technical Report for Cour d'Alene Mines, 116 p. (posted on www/.sedar.com, April 20, 2006).
Goldfarb, R.J., Miller, L.D., Leach, D.L., and Snee, L.W, 1997, Gold deposits in metamorphic rocks in Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska: Economic Geology Monograph 9, p. 151-190.
Miller, L.D., Goldfarb, R.J., Snee, L.W., Gent, C.A., and Kirkham, R.A., 1995, Structural geology, age, and mechanisms of gold vein formation at the Kensington and Jualin deposits, Berners Bay district, southeast Alaska: Economic Geology, v. 90, p. 343-368.
Reporters J.C. Barnett and L.D. Miller (Juneau, Alaska ); D.J. Grybeck (Port Ludlow, WA)
Last report date 6/5/2008