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Klukwan

Prospect in Alaska, United States with commodities Iron, Titanium, Gold, Copper, Palladium, Platinum, Vanadium
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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. 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 10309003
MRDS ID A013094
Record type Site
Current site name Klukwan
Related records 10096787

Geographic coordinates

Geographic coordinates: -135.88212, 59.41975 (WGS84)
Relative position The prospect is approximately 1.5 miles north, northeast of the village of Klukwan at an elevation of 1,200 feet in a canyon on the southwest side of Iron Mountain. It is the approximate center of a 4-mile-long deposit that extends to the northwest and southeast and is about 1 mile wide. It is shown as location 16 of Cobb (1972 [MF 424]) and location SE22 of Nokleberg and others (1987).

Site location context

Political divisions (FIPS codes)

Haines(Borough)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Skagway B-3(quadrangle 1:63,360 scale)

Skagway SE(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)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Iron Primary
Titanium Critical Primary
Gold Secondary
Copper Secondary
Palladium Critical Secondary
Platinum Critical Secondary
Vanadium Critical Secondary

Materials information

Materials Type of material
Bornite Ore
Chalcopyrite Ore
Gold Ore
Hematite Ore
Ilmenite Ore
Palladium Ore
Platinum Ore
Titaniferous Magnetitite Ore

Alteration

  • Epidote alteration of hornblende diorite near contact with pyroxenite.

Mineral occurrence model information

Model code 23
USGS model code 9
Deposit model name Alaskan Cr-Pt (PGE)
Mark3 model number 120

Nearby scientific data

(1) -135.88212, 59.41975
ListMap

Economic information

Comments on the geologic information

  • Geologic Description = The Klukwan mafic/ultramafic complex lies within the Taku Terrane of Berg (1978) and forms the north end of the Klukwan-Duke belt (Brew and Morrell, 1978) of concentrically zoned, mafic/ultramafic complexes of probable middle Cretaceous age. The Klukwan ultramafic, a pyroxenite which hosts the deposit (MacKevett and others, 1974), is surrounded by hornblende diorite which is in contact with Cretaceous metabasalt to the west and Tertiary quartz diorite to the east. The pyroxenite is approximately 4 miles long in a northwest-southeast direction and up to 1.5 miles wide (Still, 1984 [OF 21-84]). The pyroxenite is composed principally of augite and hornblende with lesser amounts of feldspar, epidote, chlorite, magnetite, ilmenite, and at some locations, sulfides. Accessory to trace silicates include hematite, spinel, and leucoxene (MacKevett and others, 1974). The sulfides are mostly chalcopyrite, but pyrrhotite, pyrite, and bornite occasionally occur (Still, 1984 [OF 21-84]). The magnetite, which is titaniferous, and ilmenite occur as disseminations and as lenses of almost pure magnetite-ilmenite. Magnetite is typically interstitial to pyroxene and idiomorphic against hornblende, indicating that it formed after pyroxene but before hornblende (MacKevett and others, 1974). According to Taylor and Noble (1969), textural evidence indicates that the titaniferous magnetite recrystallized prior to crystallization of the hornblende. Robertson (1956) estimates the pyroxenite to contain from 5% to 51% magnetite and ilmenite. He also noted that the greatest concentration of titaniferous magnetite occurs in the lower portions of the pyroxenite. Taylor and Noble (1969), however, report a relatively uniform titaniferous magnetite content of 15 to 20% for the pyroxenite. Still (1984 [OF 21-84]) noted: 1) elevated gold, platinum, and palladium values in the Klukwan mafic/ultramafic complex are generally associated with sulfides, predominantly chalcopyrite, and are generally not associated with magnetite; 2) intermittent low grade mineralization averaging an estimated 750 to 1,500 ppm copper occurs along the basal contact of the pyroxenite near its southern end; and 3) hydrothermal pinch and swell veins, thought to be residual material from the ultramafic, that contain irregular sulfide mineralization occupy northerly striking, steeply dipping, shear zones near the southeastern margin of the pyroxenite. Assays of these veins contained up to 0.14 ounces of gold per ton, 0.003 ounces of platinum per ton, 0.008 ounces of palladium per ton, and 6.5% copper. Clark and Greenwood (1972), based on analyses of 10 samples from the Klukwan mafic/ultramafic complex indicate that it has an average platinum and palladium contents of 0.046 and 0.040 ppm respectively, with maximum values for both platinum and palladium of 0.100 ppm. According to Still (1984 [OF 21-84]), samples assay a maximum of 46.2% iron, 6.5% copper, 4.95% titanium, 0.0156 ounces of gold per ton, 0.031 ounces of platinum per ton, 0.011 ounces of palladium per ton, and 2,730 ppm vanadium. In their metallurgical study, Wells and Thorne (1953) commented that most of the titanium occurs as sphene. Other workers do not mention the presence of sphene (MacKevett and others, 1974; Robertson, 1956; Still, 1984 [OF 21-84]) and refer to magnetite and ilmenite as the main titanium-bearing minerals.
  • Age = Coeval with the Cretaceous pyroxenite (Still, 1984 [OF 21-84]).

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Comments on exploration

  • Status = Active

Mining district

District name Juneau (Skagway subdistrict)

Comments on the reserve resource information

  • Reserves = Robertson (1956) estimates the deposit to contain between 1 and 5 billion tons of pyroxenite with an average grade of about 13% iron. This estimated resource includes a zone in the lower part of the pyroxenite that he estimates to contain 500 million tons that contain 20% +5% iron. Berg and Cobb (1967) cite several billion tons of rock containing about 13% magnetic iron. Still (1984 [OFR 21-84]) cites a 1972 unpublished report by the Henry J. Kaiser Company that estimates a reserve of 3.5 billion tons with a soluble iron content of 16.8%. Page and others (1973) refer to a published reserve of 500 million tons of titaniferous magnetite with an average platinum group metals content of 0.0027 ounces per ton. However, Still's observation (1984 [OFR 21-84]) that gold, platinum, and palladium are associated with sulfides and not with magnetite does not support that reserve figure.

Comments on the workings information

  • Workings / Exploration = According to Still (1984 [OFR 21-84]), claims covering both the alluvial (SK031) and lode occurrences were staked in 1946. The Alaska Iron Mines company was created to develop the deposit. Work through 1961 included sampling and diamond drilling of the lode, pit sampling and churn drilling of the placer, aeromagnetic and ground magnetic surveys, and surface mapping. A pilot mill was constructed and copper concentrates were produced for metallurgical testing. The claims were leased to Columbia Iron Mining Company in 1961 and some claims were patented in 1964. The property reverted back to Alaska Iron Mines in 1972. Wells and Thorne (1953) reported that the most effective metallurgical treatment resulted from wet magnetic separation of ore ground to minus-20 mesh, followed by grinding and retreatment of the rougher concentrate. This produced concentrates with 62% to 64% iron and total iron recoveries of 45% to 97%, depending on the head grades of the samples. These recoveries corresponded to a recovery of about 98% of the magnetic iron. The titanium-oxide content of the concentrates from low-grade ores averaged about 2.2%. Concentrates from higher-grade samples contained up to 4.2% titanium dioxide.

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Still, 1984 (OF 21-84)

General comments

Subject category Comment text
Deposit Model Name = Disseminated magmatic PGE-Fe-Ti minerals in a zoned ultramafic body (Cox and Singer, 1986; model 9),
Deposit Other Comments = This prospect is within about 1 mile of the Alaska, Chilkat Bald Eagle Preserve.

Reporter information

Type Date Name Affiliation Comment
Reporter 04-FEB-2001 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

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