Unnamed (on Butterworth Island)

Prospect in Alaska, United States with commodities Silver, Lead, Zinc
Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Commodities
  6. Materials information
  7. Mineral occurrence model information
  8. Nearby scientific data
  9. Economic information about the deposit and operations
  10. Mining district
  11. Links to other databases
  12. Bibliographic references
  13. General comments
  14. Reporter information

Geologic information

Identification information

Deposit ID 10308055
Record type Site
Current site name Unnamed (on Butterworth Island)

Geographic coordinates

Geographic coordinates: -133.05687, 56.53274 (WGS84)
Relative position Prospect long known but not described in the literature; the site can be confidently located at the southeastern tip of Butterworth Island in the channel between Woewodski Island and Kupreanof Island. The deposit extends out into the flat that uncovers at low tide between Butterworth Island the the small unnamed island south of it. Near the northeast corner of section 3, T. 62 S, R. 79 E. Called the 'Mad Dog' outcrop by Houston Oil and Minerals in 1980 (Book 12, pages 687-738, Recorder's Office, Petersburg Recording District).

Site location context

Political divisions (FIPS codes)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Petersburg C-4 SE(quadrangle 1:24,000 scale)

Petersburg N(quadrangle 1:100,000 scale)

Petersburg(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Central Southeast Alaska(hydrologic accounting unit)

Southeast Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Tongass National Forest(National Forest)

National Forest UND(Type of land area)

UND(Federal land areas administered by UND)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Lead Primary
Zinc Critical Primary

Materials information

Materials Type of material
Galena Ore
Pyrite Ore
Sphalerite Ore

Mineral occurrence model information

Model code 184
USGS model code 28a
Deposit model name Massive sulfide, kuroko
Mark3 model number 93
Model code 187
USGS model code 28a.1
Deposit model name Massive sulfide, Sierran kuroko
Mark3 model number 44

Nearby scientific data

(1) -133.05687, 56.53274

Economic information

Comments on the geologic information

  • Geologic Description = A prospect known since the late 1970's but not well documented. Consists of volcanogenic massive sulfide layers in Triassic Hyd Group rocks analogous to other similar deposits in the Duncan-Zarembo mineral belt as defined by Berg and Grybeck (1980) and Berg (1981). . Brew (1997 [OF 97-156-J]) maps the rocks in the vicinity as Cretaceous diorite and Mesozoic volcanic rocks but recent mapping by Karl (oral communication, 1998) indicates that at least some Triassic Hyd Group rocks are exposed at the southeast end of Butterworth Island.
  • Age = Probably Triassic based on analogy with other volcanogenic massive sulfide deposits in the area.

Economic information about the deposit and operations

Development status Prospect

Comments on exploration

  • Status = Active?

Mining district

District name Kupreanof

Comments on the production information

  • Production Notes = None

Comments on the workings information

  • Workings / Exploration = Has been known since at least the late 1970's and has been examined and sampled by a succession of companies. Houston Oil and Minerals documented their 1980 work at the site with their annual report of assessment on the claims they held on the deposit (Book 12, pages 687-738, Recorder's Office, Petersburg Recording District) but there is little public record of more recent work.

Reference information

Bibliographic references

  • Deposit

    Berg, H. C., and Grybeck, Donald, 1980, Upper Triassic volcanogenic Zn-Pb-Ag (-Cu-Au) mineral deposits near Petersburg, Alaska: U.S. Geological Survey Open-File Report 80-527, 11 p., 1 oversize sheet.

  • Deposit

    Berg, H.C., 1981, Upper Triassic volcanogenic massive sulfide metallogenic province identified in southeastern Alaska, in Albert, N.R.D., and Hudson, T.L., eds., The United States Geological Survey in Alaska: accomplishments during 1979: U.S. Geological Survey Circular 823-B, p. B104-B108.

  • Deposit

    Brew, D.A., 1997, Reconnaissance geologic map of the Petersburg C-4 quadrangle, southeastern Alaska: U.S. Geological Survey Open-File Report 97-156-J, 21 p., 1 sheet, scale 1:63,360.

Comments on the references

  • Primary Reference = This description

General comments

Subject category Comment text
Deposit Model Name = Barite facies of a Kuroko volcanogenic massive-sulfide model (Cox and Singer, 1986m, model 28a). Alternatively a barite facies of a volcanogenic Sierran Kuroko model (Bliss, 1992, model 28a1)

Reporter information

Type Date Name Affiliation Comment
Reporter 01-NOV-98 H.C. Berg and D.J. Grybeck U.S. Geological Survey

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

Authoritative Alaska resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.