Iron Bridge

Prospect in Alaska, United States with commodities Silver, Gold, Copper

Geologic information

Identification information

Deposit ID 10308258
Record type Site
Current site name Iron Bridge

Geographic coordinates

Geographic coordinates: -136.11214, 59.54975 (WGS84)
Relative position This prospect is approximately 3/4 mile north-northwest of the junction of Nataga Creek and the Kelsall River. It is in the NW1/4, section 8, T. 27 S., R. 55 E. of the Copper River Meridian. It is shown as location 3 by Still and others (1991) and as location 28 by Gilbert and others (1991).
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Gold Primary
Copper Primary

Materials information

Materials Type of material
Malachite Ore
Sphalerite Ore

Nearby scientific data

(1) -136.11214, 59.54975

Comments on the geologic information

  • Geologic Description = This prospect consists of malachite-stained silicified rocks that occur in metamorphosed volcanic and sedimentary rocks (Still and others, 1991). Gilbert and others (1991) reported samples that contained up to 0.041 ppm gold, 5.6 ppm silver, and 2,960 ppm copper. There is very little information about this prospect. Mapping to the east by Gilbert and others (1990) suggests that the metamorphosed volcanic and sedimentary rocks described by Still and others (1991) are a roof pendant within Cretaceous to Tertiary intrusive rocks that are part of the Coast Range batholith.
  • Age = Unknown. The mineralization may be related to Cretaceous to Tertiary plutonic bodies mapped to the east by Gilbert and others (1990).

Economic information

Economic information about the deposit and operations

Development status Prospect

Comments on exploration

  • Status = Probably inactive

Mining district

District name Juneau (Skagway subdistrict)

Comments on the workings information

  • Workings / Exploration = In the 1970's, Mr. Jones, a local prospector, prospected cuts in a newly built logging road. Shallow trenches and stockpiles of malachite-stained silicified rocks were discovered in this thickly overgrown area in 1988 (Still and others, 1991).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF SK075

Bibliographic references

  • Deposit

    Gilbert, W.G., Still, J.C., Burns, L.E., Wier, K.R., and Redman, E.C., 1991, Geochemistry of Haines-Klukwan-Porcupine area, southeastern Alaska: Alaska Division of Geological and Geophysical Surveys Report of Investigations 91-5, 1 sheet, scale 1:63,360, 75 p.

  • Deposit

    Still, J.C., 1991, Bureau of Mines mineral investigations in the Juneau mining district, Alaska, 1984 - 1988, v. 2, Detailed mine, prospect, and mineral occurrence descriptions, section A, Haines-Klukwan-Porcupine subarea: U.S. Bureau of Mines of Mines Special Publication, 214 p.

  • Deposit

    Still, J.C., Hoekzema, R.B., Bundtzen, T.K., Gilbert, W.G., Wier, K.R., Burns, L.E., and Fechner, S.A., 1991, Economic geology of Haines-Klukwan-Porcupine area, southeastern Alaska: Alaska Division of Geological and Geophysical Surveys Report of Investigations 91-4, 156 p., 5 sheets, scale 1:63,360.

  • Deposit

    Gilbert, W.G., Clough, A.H., Burns, L.E., Kline, J.T., Redman, E.C., and Fogels, E.J., 1990, Reconnaissance geology and geochemistry of the northeast Skagway quadrangle, Alaska: Alaska Division of Geological and Geophysical Surveys Report of Investigations 90-5, 2 sheets, scale 1:125,000.

Comments on the references

  • Primary Reference = Still and others, 1991

General comments

Subject category Comment text
Deposit Model Name = Too little information to assign a model type.
Deposit Other Comments = This prospect is immediately west of the Alaska, Chilkat Bald Eagle Preserve.

Reporter information

Type Date Name Affiliation Comment
Reporter 04-FEB-01 T.C. Crafford T. Crafford & Associates