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Quartz Hill

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. 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 10096785
MRDS ID A012355
Record type Site
Current site name Quartz Hill
Related records 10185505

Geographic coordinates

Geographic coordinates: -130.4848, 55.40282 (WGS84)
Relative position The surface expression of the Quartz Hill deposit occupies a mile-square area that encompasses Quartz Hill and parts of the upper drainages of White and Beaver Creeks (sections 1, 2, 26, 34, 35, and 36, T. 74 and 75 S., R. 98 E., of the Copper River Meridian.). The map site is at the summit of Quartz Hill and is accurate within a few hundred feet. The site corresponds to loc. 105 in Elliott and others (1978).

Site location context

Political divisions (FIPS codes)

Prince of Wales-Hyder(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Ketchikan B-2(quadrangle 1:63,360 scale)

Ketchikan SE(quadrangle 1:100,000 scale)

Ketchikan(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Southern 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
Pyrite Ore
Quartz Gangue

Alteration

  • (Local) Pyritization, silicification.

Mineral occurrence model information

Model code 80
USGS model code 21b
Deposit model name Porphyry Mo, low-F

Host and associated rocks

  • Host or associated Associated
    Rock type Metamorphic Rock > Gneiss
  • Host or associated Host
    Rock type Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Quartz Latite
    Rock unit name Quartz Hill Stock;Quartz Hill Stock
    Rock description Quartz Hill Stock;Quartz Hill Stock

Nearby scientific data

(1) -130.4848, 55.40282
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = The country rocks in the general area of the Quartz Hill deposit include: Cretaceous or Tertiary quartz diorite, granodiorite, and quartz monzonite of the Coast Range batholith; hypabyssal stocks and associated dikes of Miocene or Oligocene granite and gabbro; Tertiary lamprophyre dikes that postdate the stocks; and Tertiary and Quaternary basalt and andesite lava flows and cinder cones (Berg and others, 1988).? the Quartz Hill deposit consists of a molybdenite-quartz stockwork and molybdenite fracture coatings in a hypabyssal, Miocene or Oligocene, composite stock and associated apophyses of porphyritic, aplitic, and aphanitic quartz monzonite and quartz latite (Elliott and others, 1976; Hudson and others, 1977, 1978, 1979). Molybdenite-quartz veinlets and fracture coatings also occur in the country rocks near the stock. Pyrite is common, chiefly as disseminated grains and small veinlets in the porphyritic rocks, and in the country rocks near the stock.? the Quartz Hill deposit was discovered in 1974. Since then, the orebody has been defined by more than 450 drill holes totalling about 265,000 feet (Maas and others, 1995, p. 265). Two test adits, totalling nearly 5,000 feet of underground workings, were driven in 1981 to better define the deposit and to collect metallurgical test samples. The orebody is generally tabular and subhorizontal. Assuming a cutoff grade of 0.05% molybdenum sulfide (MoS2), the orebody has a surface area of about 5,000 feet by 10,000 feet, and extends to a depth of up to 1,700 feet. Resource estimates vary, depending on cutoff grades. In 1992, the property owners reported a 'probable resource' of 210 million metric tons (mt) averaging 0.22% MoS2, and an additional 'possible resource' of 1.2 billion mt averaging 0.12% MoS2. A more widely publicized estimate is a probable resource of 444 million mt containing 0.219% MoS2, and a possible resource of 1.36 billion mt averaging 0.136% MoS2 (Maas and others, 1995, p. 265).
  • Age = Miocene or Oligocene.

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Comments on exploration

  • Status = Active

Mining district

District name Ketchikan

Comments on the reserve resource information

  • Reserves = the orebody is generally tabular and subhorizontal. Assuming a cutoff grade of 0.05% molybdenum sulfide (MoS2), the orebody has a surface area of about 5,000 feet by 10,000 feet, and extends to a depth of up to 1,700 feet. Resource estimates vary, depending on cutoff grades. In 1992, the property owners reported a 'probable resource' of 210 million metric tons (mt) averaging 0.22% MoS2, and an additional 'possible resource' of 1.2 billion mt averaging 0.12% MoS2. A more widely publicized estimate is a probable resource of 444 million mt containing 0.219% MoS2, and a possible resource of 1.36 billion mt averaging 0.136% MoS2 (Maas and others, 1995, p. 265).

Comments on the workings information

  • Workings / Exploration = The Quartz Hill deposit was discovered in 1974. Since then, the orebody has been defined by more than 450 drill holes totalling about 265,000 feet (Maas and others, 1995, p. 265). Two test adits, totalling nearly 5,000 feet of underground workings, were driven in 1981 to better define the deposit and to collect metallurgical test samples.

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Maas and others, 1995

General comments

Subject category Comment text
Deposit Model Name = Porphyry Mo, Low-F (Cox and Singer, 1986; model 21b)
Deposit Other Comments = This world-class deposit is estimated to contain 10% of the free world's known reserves of molybdenum.

Reporter information

Type Date Name Affiliation Comment
Reporter 05-JUL-1999 H.C. Berg U.S. Geological Survey

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.