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

Lost River

Prospect in Alaska, United States with commodities Silver, Beryllium, Copper, Fluorine-Fluorite, Lead, Tin, 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. 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 10308735
Record type Site
Current site name Lost River
Alternate or previous names Grothe-Pearson, Tozer

Geographic coordinates

Geographic coordinates: -167.1724, 65.45127 (WGS84)
Relative position This prospect is a 0.75 mile, east-west trending zone along the Rapid River fault where it crosses Lost River valley. This is approximately 4.5 miles upstream from the mouth of Lost River on the Bering Sea (21 miles west of Brevig Mission). The prospect is best exposed on a low bench on the east side of the river at elevations of 200 to 250 feet just north of the mouth of Tin Creek. This prospect was not separately identified by Cobb and Sainsbury (1972) or Cobb (1975). It is also known as the Grothe-Pearson prospect (Sainsbury, 1969, plate 5); it merges to the west with the Bessie-Maple prospect (TE038) and to the south with the Idaho prospect (TE040). The Tozer prospect (Sainsbury, 1969, plate 5) is included here as part of the Lost River valley prospect.

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

BLM(Federal land areas administered by BLM)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Beryllium Critical Primary
Copper Primary
Fluorine-Fluorite Critical Primary
Lead Primary
Tin Critical Primary
Zinc Critical Primary

Comments on the commodity information

  • Gangue = white mica

Materials information

Materials Type of material
Cassiterite Ore
Chrysoberyl Ore
Fluorite Ore
Galena Ore
Sphalerite Ore
Stannite Ore
Arsenopyrite Gangue
Diaspore Gangue
Pyrite Gangue
Tourmaline Gangue

Alteration

  • The veining and related replacement in this area can be thought of as distal alteration to more intense, tin metallization at depth. Mass balance calculations show significant SiO2, Al2O3, alkali, and fluorine enrichment with this type of alteration (Sainsbury, 1968, p. 1567).

Nearby scientific data

(1) -167.1724, 65.45127
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = 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. Sainsbury (1969) indicates that the Rapid River fault is continuous for another 1.5 miles east of this prospect but earlier mapping (Sainsbury, 1964) suggests the possiblity that the Rapid River fault is offset by the north-south trending Lost River normal fault in the area of this prospect. Bedrock in the prospect area is Ordovician limestone locally cut by thin felsic dikes. Mineralization is probably at least locally present over about 5,000 feet of strike of the Rapid River fault including the Lost River valley and Bessie-Maple prospect (TE038) to the west. Soil samples across this prospect on the east side of Lost River are highly anomalous in base metals, tin, and beryllium (Sainsbury, 1969, plate 5). Mineralization exposed in dozer trenches is of several types; (1) fluorite and chyrsoberyl veins with diaspore, tourmaline , and white mica, (2) fluorite veins with or without fine-grained silica, (3) sulfide-bearing veins with stannite and related gossanous zones, and (4) quartz-muscovite- tourmaline-pyrite veinlets with up to 1.1% tin. Samples of the fluorite-beryllium mineralization contain 0.4 to almost 2% BeO and 50 to 59% fluorite (Sainsbury, 1963, p. 8). The complex, polymetallic character of the sulfide mineralization is well developed here as it is in the Bessie-Maple prospect to the west. Gossanous samples from trenches contain up to several percent lead, almost 1% copper, 4% zinc, 0.9% tin, 8 opt silver, and greater than 1,000 ppm arsenic (Hudson, 1983).
  • Age = The age of the mineralization is 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
Commodity type Both

Comments on exploration

  • Status = Active

Mining district

District name Port Clarence

Comments on the production information

  • Production Notes = None

Comments on the reserve resource information

  • Reserves = Not defined

Comments on the workings information

  • Workings / Exploration = Several surface dozer trenches and reconnaissance geochemical surveys have been completed on the bench east of Lost River.

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Sainsbury, 1969; Hudson, 1983

General comments

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

Reporter information

Type Date Name Affiliation Comment
Reporter 10-MAY-1998 Travis L. Hudson Applied Geology

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.