Cap

The Cap is a barium-barite, silver, lead, gold, and zinc mine located in Alaska.

About the MRDS Data:

All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.

Mine Info

Satelite View

MRDS mine locations are often very general, and in some cases are incorrect. Some mine remains have been covered or removed by modern industrial activity or by development of things like housing. The satellite view offers a quick glimpse as to whether the MRDS location corresponds to visible mine remains.

Site Name

Primary: Cap

Commodity

Primary: Barium-Barite
Primary: Silver
Primary: Lead
Primary: Gold
Primary: Zinc
Secondary: Antimony

Location

State: Alaska
District: Juneau (Skagway subdistrict)

Land Status

Not available

Holdings

Not available

Workings

Not available

Ownership

Not available

Production

Not available

Deposit

Record Type: Site
Operation Category: Prospect
Operation Type: Unknown
Years of Production:
Organization:
Significant:

Physiography

Not available

Mineral Deposit Model

Model Name: Massive sulfide, Besshi (Japanese deposits)
Model Name: Massive sulfide, kuroko

Orebody

Not available

Structure

Not available

Alterations

Not available

Rocks

Name: Greenschist
Role: Associated
Age Type: Associated Rock
Age Young: Late Permian

Analytical Data

Not available

Materials

Ore: Barite
Ore: Galena
Ore: Pyrite
Ore: Sphalerite
Ore: Tetrahedrite

Comments

Comment (Geology): Geologic Description = This prospect consists of barite-rich sulfide lenses up to 8 feet thick in a 50-foot-thick, 220-foot-long, iron-stained zone capped by volcanics that outcrop above the Saksaia glacier. The full extent of the prospect is hidden by glacier and cover. Pyrite, sphalerite, galena and tetrahedrite are found in the barite lenses. Samples contained up to 50% barium, 1.1% zinc, 0.33% lead, 277.7 ppm silver, 1.371 ppm gold, and 100 ppm cobalt. (Still, 1984 [OF 118-84], and Still and others, 1991). The mineralization is near a cupola of Cretaceous quartz diorite. It is mineralogically similar to the other barite-rich deposits lodes in the area such as the Main Zone/Palmer (SK066) and Nunatak (SK058) prospects (MacKevett and others, 1974).? Rubicon Minerals (1998) cites the results of work by Newmont Gold Company that includes a 43-foot channel sample that contained 247.6 ppm silver, 0.263 ppm gold, 2,753 ppm zinc, 1,803 ppm lead, and 174 ppm copper as well as a drill hole with a 76.3-foot-thick intercept that averaged 3.7 ounces of silver per ton. This prospect lies along a northwesterly mineral trend that includes the Nunatak (SK058), Cap, and Mt. Henry Clay (SK068) prospects. Rubicon Minerals considers these prospects to all occur at the same mineralized stratigraphic horizon and attributes their distribution to a northwest-trending, shallowly plunging antiform that brings the massive-sulfide horizon close to the surface (Rubicon Minerals, 1998). The Cap prospect and other similar prospects in the Mt. Henry Clay area are probably correlative with the Windy Craggy deposit in Canada and the Greens Creek deposit on Admiralty Island and are therefore Late Triassic (Still, 1984 [OF 118-84]; Newberry and others, 1997).

Comment (Exploration): Status = Active

Comment (Geology): Age = The Cap prospect and other similar prospects in the Mt. Henry Clay area are probably correlative with the Windy Craggy deposit in Canada and the Greens Creek deposit on Admiralty Island and are therefore Late Triassic (Still, 1984 [OF 118-84]; Newberry and others, 1997).

Comment (Deposit): Model Name = Probably a Kuroko- or Besshi-type volcanogenic massive sulfide (Cox and Singer, 1986; models 28a or 24b).

Comment (Reference): Primary Reference = Still, 1984 (OF 118-84)

References

Reference (Deposit): Still, J.C., 1984, Stratiform massive sulfide deposits in the Mt. Henry Clay area, southeast Alaska: U.S. Bureau of Mines Open-File Report 118-84, 65 p.

Reference (Deposit): Berg, H.C., 1984, Regional geologic summary, metallogenesis, and mineral resources of southeastern Alaska: U.S. Geological Survey Open-file Report 84-572, 298 p., 1 plate, scale approx. 1:600,000.

Reference (Deposit): MacKevett, E.M., Jr., Robertson, E.C., and Winkler, G.R., 1974, Geology of the Skagway B-3 and B-4 quadrangles, southern Alaska: U.S. Geological Survey Professional Paper 832, 33 p.

Reference (Deposit): Gilbert, W.G., and Redman, E.C., 1989, Lode deposits, prospects, and occurrences of the Porcupine mining area, southeast Alaska: U.S. Bureau of Mines Open-File Report 17-89, 1 sheet, scale 1:39,600.

Reference (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.

Reference (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.

Reference (Deposit): Rubicon Minerals, 1998, Palmer VMS Project, southeast Alaska, Executive Summary: unpublished report by Rubicon Minerals Corporation, Vancouver, British Columbia, 25 p.

Reference (Deposit): Newberry, R.J., Crafford, T.C., Newkirk, S.R., Young, L.E., Nelson, S.W., and Duke, N.A., 1997, Volcanogenic massive sulfide deposits of Alaska, in Goldfarb, R.J. and Miller, L. D., eds., Mineral deposits of Alaska: Economic Geology Monograph 9, p. 120-150.

The Top Ten Gold Producing States

These ten states contributed the most to the gold production that built the West from 1848 through the 1930s. The Top Ten Gold Producing States.