Rapid River

Prospect in Alaska, United States with commodities Beryllium, Fluorine-Fluorite, Silver, Copper, Lead, Tin, Zinc
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. 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 10308402
Record type Site
Current site name Rapid River

Geographic coordinates

Geographic coordinates: -167.3034, 65.44826 (WGS84)
Relative position Rapid River is the major west tributary of Lost River. Its mouth is located one mile upstream from the mouth of Lost River on the Bering Sea. This prospect is located in the valley of Rapid River, about 5.5 miles upstream from its confluence with Lost River. The area of mineralization extends across Rapid River valley but it is best developed on a small knoll on the north side of the drainage at 471 feet elevation. This is locality 3 of Cobb and Sainsbury (1972). Cobb (1975) summarized relevant references under the name 'Rapid R.'.

Site location context

Political divisions (FIPS codes)

Nome(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Teller B-5(quadrangle 1:63,360 scale)

Teller SE(quadrangle 1:100,000 scale)

Teller(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Imuruk Basin(hydrologic unit)

Norton Sound(hydrologic accounting unit)

Northwest(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Diomede 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
Beryllium Critical Primary
Fluorine-Fluorite Critical Primary
Silver Secondary
Copper Secondary
Lead Secondary
Tin Critical Secondary
Zinc Critical Secondary

Comments on the commodity information

  • Gangue = white mica

Materials information

Materials Type of material
Bertrandite Ore
Cassiterite Ore
Chrysoberyl Ore
Euclase Ore
Fluorite Ore
Galena Ore
Phenacite Ore
Sphalerite Ore
Diaspore Gangue
Hematite Gangue
Tourmaline Gangue
Silica Gangue
Mica Gangue

Alteration

  • (Local) Some lamprophere dikes have tactite borders but these may not be related to mineralization. The origin of dolomite and dolomite breccia is also not clear here. Mass balance calculations show significant SiO2, Al2O3, alkali, and fluorine enrichment with mineralization (Sainsbury, 1968, p. 1567).

Nearby scientific data

(1) -167.3034, 65.44826

Economic information

Comments on the geologic information

  • Geologic Description = Banded fluorite-chrysoberyl veinlets, veins, pipes, and irregular replacements are present in Lower Ordovician limestone and dolomite in the footwall of the Rapid River fault. Sainsbury (1969; 1972) maps the Rapid River fault as a 12-mile long east-west trending thrust fault in the southern part of the York Mountains although stratigraphic relations across the fault suggest normal displacement. The fluorite-chyrsoberyl mineralization is locally present over an area 4,400 feet long (east-west) and about 1,000 feet wide. Lamprophyre dikes are also common in this area and some dike borders localize fluorite-chyrsoberyl replacements. Individual veins are generally 1 to 3 inches wide and spaced 6 to 18 inches apart but some irregular replacements are up to 25 feet across. Structures with a general east-west orientation, such as joints, small faults, and dike borders are a dominant control on mineralization. The mineralization includes minor euclase, bertrandite, and phenakite (?). Gangue minerals are diaspore, white mica, tourmaline, and hematite; fine-grained silica is locally present along the mineralized zones. BeO contents of 12 samples range from 0.15 to 1.05%; fluorite content of two samples is 57% (Sainsbury, 1963, p. 11). Diamond-drilling by Newmont Mining Company in 1963 encountered mineralization in the footwall of the Rapid River fault a few hundred feet below the surface. This drilling encountered sulfide mineralization in the cores of some veins. The sulfide minerals include galena and sphalerite; minor cassiterite is associated with the sulfides (Sainsbury, 1969, p. 77). Newmont attempted to find this early drill data in 1998 but was unsuccessful. However, the old project files did contain a report on metallugical testing of samples obtained by the 1963 drilling (Porter, 1964). One sample, a composite from drill holes 9 through 14, weighed 100 pounds and containted 12.0% CaF2 , 0.086% BeO, and 56.4% CaCO3. A second sample, a composite from drill holes 2, 8, 21, 22, and a 10-foot channel in a surface trench, weighed 50 pounds and contained 27.4% CaF2, 0.22% BeO, and 34.5% CaCO3. Bench-scale sink-float tests showed that this material could be upgraded to about 50% CaF2 and 0.35% BeO. The metallugical test results indicated that the beryllium was associated with silicate minerals and did not directly follow fluorite through the procedures.
  • Age = Assumed to be related to the development of tin systems in the Lost River area and therefore Late Cretaceous, the age of the tin-mineralizing granites there (Hudson and Arth, 1983).

Economic information about the deposit and operations

Development status Prospect

Comments on exploration

  • Status = Inactive

Mining district

District name Port Clarence

Comments on the reserve resource information

  • Reserves = Not defined

Comments on the workings information

  • Workings / Exploration = A few dozer trenches and several diamond drill holes have been completed on the prospect.

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Sainsbury, 1963; Sainsbury, 1968; Sainsbury, 1969

General comments

Subject category Comment text
Deposit Model Name = Fluorite- and beryllium-bearing veins and replacements in Ordovician limestone (Sainsbury, 1968)

Reporter information

Type Date Name Affiliation Comment
Reporter 10-MAY-98 Travis L. Hudson Applied Geology

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.