LIVE REPORT! Tucson Shows 2020 - last updated 2 hours ago. Click here to watch.
Log InRegister
Home PageAbout MindatThe Mindat ManualHistory of MindatCopyright StatusWho We AreContact UsAdvertise on Mindat
Donate to MindatCorporate SponsorshipSponsor a PageSponsored PagesMindat AdvertisersAdvertise on Mindat
Learning CenterWhat is a mineral?The most common minerals on earthInformation for EducatorsMindat ArticlesThe ElementsBooks & Magazines
Minerals by PropertiesMinerals by ChemistryAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
Mining CompaniesStatisticsUsersMineral MuseumsMineral Shows & EventsThe Mindat DirectoryDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryMineral Photography

Commonwealth Prospect, Hyder District, Prince of Wales-Outer Ketchikan Borough, Alaska, USA

This page is currently not sponsored. Click here to sponsor this page.
 
 
Site is in Misty Fiords National Monument Wilderness.
Location: The presumed location of this prospect is based on Buddington's (1929, p. 111-112 [B 807]) description of the Commonwealth group of claims, which in turn refers to somewhat ambiguous landmarks that cannot be accurately located on the Ketchikan D-1 topographic map. The map site therefore is probably accurate only within about a mile. The site is in section 34, T. 70 S., R. 99 E., of the Copper River Meridian. It corresponds to loc. 14 in Elliott and others (1978).
Geology: The country rocks in the area of the presumed site are porphyritic quartz monzonite and granodiorite of the Eocene Davis River Pluton (Smith, 1977; Berg and others, 1988). According to Buddington (1929, p. 111-112), the Commonwealth prospect(s) lie within a narrow belt of metamorphosed sedimentary rocks that form a roof pendant within the quartz monzonite. The metamorphosed strata are several hundred feet thick and include interbedded quartzite, schist, and marble. A lamprophyre dike cuts the quartz monzonite and metasedimentary rocks. The quartzite, schist, and marble have been contact metamorphosed by the intrusion of the quartz monzonite and locally contain disseminations, seams, and small masses of quartz, garnet, epidote, pyroxene, tremolite, and small amounts of sulfide minerals. The sulfide minerals include pyrrhotite, sphalerite, chalcopyrite, and molybdenite, and a quartz stringer was reported to yield gold. The age of this contact metamorphic (skarn) deposit probably is Eocene, roughly contemporaneous with the emplacement of the Davis River Pluton. The prospect was explored in the early 1900s by an 80-foot adit and an 11-foot adit.
Workings: The prospect was explored in the early 1900s by opencuts, an 80-foot adit, and an 11-foot adit.
Age: Eocene?
Alteration: Weathered pyrrhotite gives a rusty color to the surface outcrop.

Commodities (Major) - Au?, Cu, Mo, Zn
Development Status: None
Deposit Model: Cu skarn (Cox and Singer, 1986; model 18b)

Mineral List



6 entries listed. 6 valid minerals.

The above list contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.

References

Berg, H.C., Elliott, R.L., and Koch, R.D., 1988, Geologic map of the Ketchikan and Prince Rupert quadrangles, southeastern Alaska: U.S. Geological Survey Mineral Investigations Series Map I-1807, 27 p., scale 1:250,000. Buddington, A.F., 1929, Geology of Hyder and vicinity, southeastern Alaska, with a reconnaissance of Chickamin River: U.S. Geological Survey Bulletin 807, 124 p. Elliott, R.L., Berg, H.C., and Karl, S.M., 1978, map and table describing metalliferous and selected non-metalliferous mineral deposits, Ketchikan and Prince Rupert quadrangles, Alaska: U.S. Geological Survey Open-File Report 78-73-B, 17 p., 1 sheet, scale 1:250,000. Smith, J.G., 1977, Geology of the Ketchikan D-1 and Bradfield Canal A-1 quadrangles, Alaska: U.S. Geological Survey Bulletin 1425, 49 p., 1 plate.

 
Mineral and/or Locality  
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Public Relations by Blytheweigh.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2020, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: February 18, 2020 00:54:08 Page generated: January 17, 2015 20:32:55
Go to top of page