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

Riverside

Prospect in Alaska, United States with commodities Silver, Gold, Copper, 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. Mineral occurrence model information
  9. Host and associated rocks
  10. Nearby scientific data
  11. Economic information about the deposit and operations
  12. Mining district
  13. Links to other databases
  14. Bibliographic references
  15. General comments
  16. Reporter information

Geologic information

Identification information

Deposit ID 10000700
MRDS ID A011332
Record type Site
Current site name Riverside

Geographic coordinates

Geographic coordinates: -149.61283, 63.23958 (WGS84)
Relative position The prospect is on the south bank of the West Fork Chulitna River, just upstream from the mouth of Bryn Mawr Creek. It is located in sec. 26, T.19 S., R. 11 W., of the Fairbanks Meridian. Accuracy is within 0.5 miles.?This is location 7 of Cobb (1978: OFR 78-1062).

Site location context

Political divisions (FIPS codes)

Matanuska-Susitna(Borough)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Healy A-6(quadrangle 1:63,360 scale)

Healy S(quadrangle 1:100,000 scale)

Healy(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Chulitna River(hydrologic unit)

Susitna River(hydrologic accounting unit)

South Central Alaska(hydrologic subregion)

Alaska(hydrologic region)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Silver Primary
Gold Primary
Copper Secondary
Lead Secondary
Zinc Critical Secondary

Materials information

Materials Type of material
Arsenopyrite Ore
Chalcopyrite Ore
Galena Ore
Pyrite Ore
Pyrrhotite Ore
Sphalerite Ore
Quartz Gangue

Alteration

  • (Local) Narrow phyllic alteration haloes around and in porphyry dikes typically consists of sericite, quartz, and pyrite. In addition, skarn alteration minerals are garnet, pyroxene, and epidote.

Mineral occurrence model information

Model code 59
USGS model code 18b
Deposit model name Skarn Cu
Mark3 model number 8
Model code 85
USGS model code 22c
Deposit model name Polymetallic veins
Mark3 model number 46

Host and associated rocks

  • Host or associated Host
    Rock type Sedimentary Rock > Carbonate > Limestone
    Stratigraphic age (youngest) Late Triassic

Nearby scientific data

(1) -149.61283, 63.23958
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = The country rocks in the area of the Riverside prospect are Triassic, redbed sandstone, conglomerate and limestone that have been intruded by a hornblende-quartz diorite dike. The deposit is in hornfelsed bedded rocks and consists chiefly of quartz-sulfide veins, and stockworks, and of sulfide disseminations. The sulfide minerals are arsenopyrite, chalcopyrite, galena, pyrite, pyrrhotite, and sphalerite. Small, sulfide-bearing skarn deposits are in marble adjacent to the dike (unpublished report by Addwest Minerals International Ltd., 1997). Samples contain 0.02 to 0.72 ounce of gold per ton and 0.3 to 2.10 ounces of silver per ton (Ross, 1933). The relatively high gold and silver values may be due to supergene enrichment. A fault may truncate the deposit to the south. The Riverside deposit is similar in mineralogy and type to other deposits satellitic to the Golden Zone deposit (HE043).
  • Age = Late Cretaceous (70 -65 Ma), assuming that the deposit is satellitic to the Golden Zone deposit (HE043).

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Comments on exploration

  • Status = Active

Mining district

District name Valdez Creek

Comments on the workings information

  • Workings / Exploration = Mainly surface workings. There are reports of a 10-foot tunnel and 15-foot shaft that are now caved. Recent geochemical exploration has identified a broad soil anomaly that outlines the deposit. Samples contain 0.02 to 0.72 ounce of gold per ton and 0.3 to 2.10 ounces of silver per ton (Ross, 1933).

Reference information

Bibliographic references

  • Deposit

    Townsend, H.H., 1925, Assay returns: Alaska Territorial Dept. of Mines Itinerary Report 195-48, 4 p.

  • Deposit

    Ross, C.P., 1933, The Valdez Creek mining district, Alaska: U.S. Geological Survey Bulletin 849, p. 289-467.

  • Deposit

    Berg, H.C., and Cobb, E.H., 1967, Metalliferous Lode Deposits of Alaska. U.S. Geological Survey Bulletin 1246, 254 p.

  • Deposit

    Hawley, C.C., and Clark, A.L., 1974, Geology and mineral deposits of the upper Chulitna district, Alaska: U.S. Geological Survey Professional Paper 758-B, p. 1-47, 2 sheets, scale 1:12,000 and 1:48,000.

  • Deposit

    Cobb, E.H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Healy quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-1062, 113 p.

  • Deposit

    Hawley, C.C., and others, 1978, Mineral appraisal of lands adjacent to Mt. McKinley National Park, Alaska. Contract No. JO166107: U.S. Bureau of Mines Open-File Report 24-78, 274 p., 12 sheets.

  • Deposit

    Capps, S.R., 1919, Mineral resources of the upper Chulitna region: U.S. Geological Survey Bulletin 692-D, p. 207-232.

Comments on the references

  • Primary Reference = Hawley and Clark, 1974

General comments

Subject category Comment text
Deposit Model Name = Cu skarn; Polymetallic veins (Cox and Singer, 1986; models 18b, 22c)
Deposit Model Number = 18b, 22c

Reporter information

Type Date Name Affiliation Comment
Reporter 07-APR-2000 N. Van Wyck Stevens Exploration Management Corporation

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.