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Clifton

Prospect in Alaska, United States with commodity Molybdenum
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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. Links to other databases
  13. Bibliographic references
  14. General comments
  15. Reporter information

Geologic information

Identification information

Deposit ID 10002210
MRDS ID A013111
Record type Site
Current site name Clifton
Related records 10258422

Geographic coordinates

Geographic coordinates: -135.22211, 59.52976 (WGS84)
Relative position This prospect is marked by a shallow shaft about 1,000 feet northeast of Clifton. It is just east of the White Pass and Yukon Railroad track at an elevation of about 900 feet in the SW 1/4, section 16, T. 27 S., R. 60 E. of the Copper River Meridian. Clifton is an old station on the White Pass and Yukon Railroad that is essentially coincident with Bench Mark 855 ('BM 855'). Smith (1942) refers to the location of a 30-foot tunnel about 80 feet south of the shaft on the west side of the railroad track. Herbert and Race (1965), however, mention a short tunnel on the west side of the railroad track west of their map location 2 , which is plotted about 2,500 feet southwest of Clifton. This prospect is location 21 of Cobb (1972 [MF 424]).

Site location context

Political divisions (FIPS codes)

Hoonah-Angoon(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Skagway C-1(quadrangle 1:63,360 scale)

Skagway NE(quadrangle 1:100,000 scale)

Skagway(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Chilkat-Skagway Rivers(hydrologic unit)

Northern Southeast Alaska(hydrologic accounting unit)

Southeast Alaska(hydrologic subregion)

Alaska(hydrologic region)

Federal lands

Tongass National Forest(National Forest)

National Forest FS(Type of land area)

FS(Federal land areas administered by FS)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Molybdenum Primary

Materials information

Materials Type of material
Molybdenite Ore
Quartz Gangue

Alteration

  • (Local) None is specifically referenced in the geologic descriptions in Smith (1942) but Herbert and Race (1965) suggest bleaching and possibly, silicification.

Host and associated rocks

  • Host or associated Host
    Rock type
    Stratigraphic age (youngest) Middle Eocene
    Stratigraphic age (oldest) Early Eocene
    Chronological age 48.8
    Dating method U-Pb (zircon)
    Type of media Zircon
    Stratigraphic age (youngest) Middle Eocene
    Stratigraphic age (oldest) Early Eocene
    Chronological age 48
    Dating method U-Pb (zircon)
    Type of media Zircon

Nearby scientific data

(1) -135.22211, 59.52976
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = According to Herbert and Race (1965), sparse molybdenite occurs in an aplite dike at a shallow shaft northeast of Clifton. The aplite dike occurs within a quartz monzonite that contains strong horizontal sheeting, vertical joints, and generally horizontal silicified bands with very sparse molybdenite. The molybdenum mineralization may be associated with a N60E fracture zone. Five stream sediment samples collected over an interval of approximately 4,000 feet along the railway to the southwest of Clifton contained 13 to 120 ppm molybdenum. Smith (1942) summarizes the description of J.B. Mertie, Jr. who visited the site in 1917. According to Mertie, the molybdenite appears to occur in a rock that varies from alaskite to granite and contains no mafic minerals. The molybdenite is distributed in patches throughout the granitic rock and was estimated to constitute about 1% of the rock. The granite was described as being extensively sheeted horizontally and cut by prominent joint planes that strike N50W and dip 72 degrees to the southwest.? the Clifton prospect occurs within the Clifton granite of Gilbert and others (1990) who note the presence of widespread molybdenite mineralization in the granite and attribute it to the high level of emplacement and rapid cooling of the granite. Clough (1991 [BOM, v. 2, sec C]) observed that the Clifton granite contains miarolitic cavities and that it is the youngest granite in the region. U-Pb zircon age dates for the Clifton granite of 48.8 +/- 1.0 m.y. (Gehrels and others, 1991) and 48 +/- 2 m.y. (Barker and others, 1986) establish a likely age for the Clifton prospect.
  • Age = U-Pb zircon age dates for the Clifton pluton of 48.8 +/- 1.0 m.y. (Gehrels and others, 1991) and 48 +/- 2 m.y. (Barker and others, 1986) establish a likely age for the Clifton prospect.
  • Age = Chron age is for the Clifton pluton.

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Juneau (Skagway subdistrict)

Comments on the workings information

  • Workings / Exploration = Brooks (1918) reported a 10-foot shaft and a 25-foot adit in 1916. In 1917, the prospect was examined by J.B. Mertie, Jr. who reported a 15-foot deep shaft on east side of railroad track about 1,000 north of Clifton. About 80 feet south of the shaft on the west side of the track, an approximately 30-foot tunnel was driven S55E along a prominent joint plane (Smith, 1942). Herbert and Race (1965) also refer to the shaft and short tunnel. They note that although scattered grains of molybdenum can be found over a large area on the well-exposed slopes in the vicinity of Clifton, there is no evidence of other underground workings or surface trenching.

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Smith, 1942

General comments

Subject category Comment text
Deposit Model Name = Disseminated molybdenite in granitic rocks, possibly related to a fracture zone.

Reporter information

Type Date Name Affiliation Comment
Reporter 04-FEB-01 T.C. Crafford T. Crafford & Associates

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.