McLeod East

Occurrence in Alaska, United States with commodities Molybdenum, Silver, Copper, Manganese, Lead, Tin, Tungsten

Geologic information

Identification information

Deposit ID 10002524
MRDS ID A013467
Record type Site
Current site name McLeod East
Related records 10308505, 10308504

Geographic coordinates

Geographic coordinates: -159.27276, 63.27078 (WGS84)
Relative position The McCleod East occurrence is at the southwestern end of the Kaiyuh Mountains, approximately 11.25 miles southeast of Blackburn, an abandoned settlement on the Yukon River. The occurrence is at an elevation of 950 feet, approximately 3400 feet south of hill 1170, in the northeast corner of sec. 6, T. 26 S., R. 3 W., Kateel River Meridian. It is approximately 2200 feet east of the caved trenches at the original McLeod prospect (UL003). The location is accurate within 500 feet.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Molybdenum Primary
Silver Secondary
Copper Secondary
Manganese Secondary
Lead Secondary
Tin Secondary
Tungsten Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Molybdenite Ore
Pyrite Ore
Ferrimolybdite Ore
Quartz Gangue
Zircon Gangue

Alteration

  • (Local) The granitic stock is sericitized and locally intensely silicified.

Mineral occurrence model information

Model code 80
USGS model code 21b
Deposit model name Porphyry Mo, low-F
Model code 50
USGS model code 16
Deposit model name Climax Mo

Host and associated rocks

  • Host or associated Host
    Stratigraphic age (oldest) Late Jurassic

Nearby scientific data

(1) -159.27276, 63.27078

Comments on the geologic information

  • Geologic Description = This occurrence consists of disseminated molybdenite in talus of quartz-veined and sericitically-altered felsic intrusive rock along the southern margin of a small stock that intrudes Cretaceous strata (Bressler and others, 1979). The strata include poorly sorted, medium- to coarse-grained arkosic sandstone and subordinate siltstone, shale, and lesser intermediate to mafic volcanic rocks. The beds generally strike northwest and dip gently to the northeast and southwest (Bressler and others, 1979). The stock is leucocratic, quartz-feldspar porphyry composed of 20-40% bipyramidal to subhedral quartz and 10-30% feldspar phenocrysts in a matrix dominantly of quartz and feldspar. The stock is exposed in an area of about 2500 by 6000 feet that is elongate to the northeast. The exposure is centered along the boundary of sections 32 and 33, and the stock sends dike swarms into sections 4 and 28 (Bressler and others, 1979).? A younger suite of biotite-quartz-feldspar porphyry dikes exposed to the west at the McLeod prospect (UL003) apparently does not occur at this site (Bressler and others, 1979).? Also see UL003 and UL004.
  • Age = Late Cretaceous or Tertiary, the age of the granitic stock and its apophyses.
  • Age = The molybdenite-bearing veins presumably are related to the cooling phase of the Upper Cretaceous or Tertiary porphyritic granite stock.
  • Age = Cretaceous or Tertiary, the presumed age of the mineralized felsic intrusive hostrock.
  • Age = Host rock is Tertiary - Cretaceous.

Economic information

Economic information about the deposit and operations

Development status Occurrence
Commodity type Metallic

Mining district

District name Kaiyuh

Comments on the workings information

  • Workings / Exploration = This occurrence was discovered during reconnaissance mapping and sampling during 1979 (Bressler and others, 1979). No further work is documented.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A013467
USGS Alaska Resource Data File ARDF UL005

Bibliographic references

  • Deposit

    Lessman, J., 1979, Doyon project 1979 annual progress report: Doyon Report 79-31, 5 p. (Report held by Doyon, Ltd., Fairbanks, Alaska).

  • Deposit

    Bressler, J., Cleveland, G., Ruzicka, J., 1979, 1979 annual progress report McLeod project area: Doyon Report 79-33, 48 p. (Report held by Doyon, Ltd., Fairbanks, Alaska).

  • Deposit

    Boniwell, J.B., 1981, Airborne geophysics over the McLeod prospect, Kaiyuh Mountains, Nulato, Alaska: Doyon Report 81-05, 9 p. (Report held by Doyon, Ltd., Fairbanks, Alaska).

  • Deposit

    Boniwell, J.B., 1981, An addendum to the report on airborne geophysics over the McLeod prospect, Kaiyuh Mountains, Nulato, Alaska: Doyon Report 81-08, 16 sheets. (Report held by Doyon, Ltd., Fairbanks, Alaska.)

  • Deposit

    Joesting, H.R., 1943, Strategic mineral occurrences in interior Alaska, supplement to pamphlet no. 1: Alaska Territorial Department of Mines Pamphlet 2, 26 p.

  • Deposit

    Cobb, E.H., 1976, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Candle, Holy Cross, Norton Bay, Nulato, and Unalakleet quadrangles, Alaska: U.S. Geological Survey Open-File Report 76-866, 102 p.

Comments on the references

  • Primary Reference = Bressler and others, 1979

General comments

Subject category Comment text
Deposit Model Name = Vein and porphyry Mo (Cox and Singer, 1986; model 16a, 21b)
Deposit Model Number = 16a, 21b
Deposit Other Comments = This property is on Doyon, Ltd. selected lands. For more information, contact Doyon, Ltd., in Fairbanks, Alaska.

Reporter information

Type Date Name Affiliation Comment
Reporter 07-AUG-2001 S.S. Dashevsky Northern Associates Inc.