1. Mineral Resources
  2. Online Spatial Data
  3. Mineral Resource Data System (MRDS)

Cub Bear

Prospect in Alaska, United States with commodities Iron, Manganese, Silver, Lead, Zinc
Map
XML
JSON
KML
B
Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Commodities
  6. Materials information
  7. Alteration
  8. Host and associated rocks
  9. Nearby scientific data
  10. Economic information about the deposit and operations
  11. Mining district
  12. Reserves and resources
  13. Links to other databases
  14. Bibliographic references
  15. General comments
  16. Reporter information

Geologic information

Identification information

Deposit ID 10001947
MRDS ID A012783
Record type Site
Current site name Cub Bear
Related records 10136410

Geographic coordinates

Geographic coordinates: -165.75107, 64.71067 (WGS84)
Relative position The Cub Bear prospect is on the west side of Cripple River, about 4,000 feet northwest of the mouth of Snowshoe Gulch; the prospect is mainly on a steep easterly slope between about 750 and 1,000 feet in elevation in section 18, T. 9 S., R. 35 W., Kateel River Meridian. The location is approximately half-way between two northerly aligned masses of iron minerals (Herreid, 1970; Bundtzen and others, 1994). The prospect is locality 7 of Cobb (1972 [MF 463], 1978 [OFR 78-93]); Cobb's map location (1972 [MF 463]) appears to be about three quarters of a mile north-northeast of the true location.

Site location context

Political divisions (FIPS codes)

Nome(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Nome C-2(quadrangle 1:63,360 scale)

Solomon NW(quadrangle 1:100,000 scale)

Nome(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Nome(hydrologic unit)

Norton Sound(hydrologic accounting unit)

Northwest(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Sitnasuak Native Corporation(ANCSA Village)

ANCSA Village NTVPIC(Type of land area)

NTVPIC(Federal land areas administered by NTVPIC)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Iron Primary
Manganese Critical Primary
Silver Secondary
Lead Secondary
Zinc Critical Secondary

Comments on the commodity information

  • Gangue = sericite (white mica)

Materials information

Materials Type of material
Galena Ore
Goethite Ore
Hematite Ore
Pyrite Ore
Pyrolusite Ore
Sphalerite Ore
Dolomite Gangue
Quartz Gangue

Alteration

  • (Local) Dolomitization peripheral to iron oxide mineralization.

Host and associated rocks

  • Host or associated Host
    Rock type
    Stratigraphic age (youngest) Campanian
    Stratigraphic age (oldest) Barremian

Nearby scientific data

(1) -165.75107, 64.71067
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = The Cub Bear prospect is a ferruginous zone about 3,000 feet long and as much as 200 feet across that strikes north-northwest (Herreid, 1970, figure 6). The prospect contains a mineralized zone near Herreid's samples 1, 2, and 3 that contains anomalous zinc. The main concentration of iron is near Herreid's samples 4, 5, and 6, approximately 1,500 feet north of the zinc-bearing samples. Bedrock exposure is poor at the prospect. According to Herreid (1970, p. 28), the rubble overlying the deposit consists of goethite, dark yellow-brown ferruginous marble, crackled dolomite, medium-grained marble, and fine-grained ferruginous material. Crackled dolomite locally has goethite veinlets, with goethite psuedomorphic after pyrite. Dolomite breccia appears to form a discontinuous envelope around the iron-rich deposit.? the mineralized zone is essentially in marble of the massive marble unit of Bundtzen and others (1994); it occurs along a high-angle fault that separates the massive marble unit to the west from the graphitic schist unit to the east. The mineralized unit is most likely the lowermost massive marble, a unit that Herreid (1970) mapped in thrust contact with underlying mica schist.? the prospect has a small iron resource estimated by Shallit (1942; Mulligan and Hess, 1965, table 3) to be 10,000 long tons with 10 to 20 percent iron and a small tonnage of material containing 30 to 45 percent iron. A sample of goethite collected by Herreid contained 16 percent iron. The prospect also is locally anomalous in zinc. Samples from the south part of the prospect (Herreid's localities 1 to 3) contained as much as 2.4 percent zinc in a 10-foot chip sample. A 100-foot-long sample, collected near Herried's samples 3 to 6, contained 1,650 ppm zinc. The lead content of these samples did not exceed 67 ppm, and silver content did not exceed 1.3 ppm; no gold was detected.? the iron deposits of the Sinuk River area have generally been interpreted as gossan developed on oxidized sulfide deposits. At the Cub Bear prospect, there is some iron oxide (goethite) psuedomorphic after pyrite, consistent with this mode of origin. Alternatively, the deposits are primarily hypogene iron oxide deposits that are transitional into the carbonate-hosted base metal-fluorite-barite deposits of the area, such as at the Quarry prospect nearby (NM135). The relatively high zinc content of the Cub Bear prospect is consistent with the latter possibility. The age of the deposit is almost certainly post mid-Cretaceous, the age of metamorphism of the host marble. A Late Cretaceous origin was argued for the Quarry prospect by Brobst and others (1971).
  • Age = Post mid-Cretaceous, the age of metamorphism of the host schist and marble.
  • Age = Host rock is Pre Campanian - Post Barremian.

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Nome

Reserves and resources

  • Type In-situ
    Estimate year 1942
    Total resources 44000mt ore
    Remarks Entry carried over from Old MRDS or added later (i.e. it did not originate in ARDF)
    Commodity Subtype Grade units Group Importance Year
    Iron Fe 37 wt-pct Iron Major 1942
  • Type In-situ
    Estimate year 1942
    Total resources 4000mt ore
    Remarks Entry carried over from Old MRDS or added later (i.e. it did not originate in ARDF)
    Commodity Subtype Grade units Group Importance Year
    Iron Fe 15 wt-pct Iron Major 1942

Comments on the reserve resource information

  • Reserves = the prospect has been estimated to contain 100 tons of material with 30 to 45 percent iron and 10,000 tons with 10 to 20 percent iron (Shallit, 1942). There is some manganese oxide.

Comments on the workings information

  • Workings / Exploration = The Cub Bear prospect was developed by a series of pits and trenches before 1915 (Eakin, 1915 [B 622-I, p. 361-365]). Mertie (1918 [B 662-I, p.446]) reported that no recent work was evident in 1916. Cathcart (1922, p. 261), however, reported exploration by 12 trenches, 20 to 30 feet long and about 3 feet deep. The prospect was visited by Shallit (1942) and Mulligan (Mulligan and Hess, 1965) who estimated resources of iron at the prospect. Herreid (1970, figure 6) prepared a map of the prospect at 1:6000 scale. Herreid also assayed samples for gold, silver, copper, lead, and zinc.

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Herreid, 1970

General comments

Subject category Comment text
Deposit Model Name = Iron oxide veins and replacement of marble and schist.

Reporter information

Type Date Name Affiliation Comment
Reporter 12-MAR-00 Hawley, C.C. Hawley Resource Group
Reporter 12-MAR-00 Travis L. Hudson Hawley Resource Group

Beyond USGS

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

Maps centered on this site

Authoritative Alaska resources

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