Windy Pass

Prospect in Alaska, United States with commodities Copper, Iron, Molybdenum, Silver, Arsenic, Gold, Antimony, Zinc

Geologic information

Identification information

Deposit ID 10307768
Record type Site
Current site name Windy Pass

Geographic coordinates

Geographic coordinates: -154.06398, 63.6745 (WGS84)
Relative position The Windy Pass Skarn prospect is situated on a north-facing spur, overlooking a prominent southern tributary of Browns Fork of the Sulukna River at an elevation of 2,280 feet in the southeast corner of Section 17, T. 21 S., R. 25 E., of the Kateel River Meridian. The reporter visited the site in 1992.
(click for info)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Copper Primary
Iron Primary
Molybdenum Primary
Silver Secondary
Arsenic Secondary
Gold Secondary
Antimony Secondary
Zinc Secondary

Materials information

Materials Type of material
Arsenopyrite Ore
Chalcopyrite Ore
Molybdenite Ore
Pyrite Ore
Diopside Gangue
Epidote Gangue
Garnet Gangue
Magnetite Gangue
Phlogopite Gangue

Alteration

  • (Local) Sericite-chlorite in intrusion.

Mineral occurrence model information

Model code 59
USGS model code 18b
Deposit model name Skarn Cu
Mark3 model number 8

Nearby scientific data

(1) -154.06398, 63.6745

Comments on the geologic information

  • Geologic Description = The Windy Pass Cu-Mo-(Au)-Fe skarn prospect is associated with a small, Late Cretaceous, quartz monzonite stock that has intruded Paleozoic limestone probably equivalent to the Novi Mountain Formation (Dutro and Patton, 1982). The main mineralized area is about 200 feet by 3,000 feet (61 m by 914 m) in size. Two types of skarn are identified: (1) zones of sulfides, diopside, plagioclase, and orthoclase in endoskarn; and (2) zones of chalcopyrite, molybdenite, magnetite, phlogophite, garnet, and epidote in exoskarn within the marble front (DiMarchi and others, 1992). Chalcopyrite is the main ore mineral. Molybdenite is locally abundant. Pyrite locally contains gold values. Copper and molybdenum mainly occur in exoskarn; gold values appear to be in late stage quartz veins. Windy Pass Prospect is inferred to be Late Cretaceous, based on isotopic age dating of the quartz monzonite pluton (Moll and others, 1981). DiMarchi and others (1992, 1994) reported values as high as 0.27 ounces/ton (8.4 ppm) gold in quartz veins, 0.25 percent copper in exoskarn, and 650 ppm molybdenum in exoskarn. Clautice and others (1993) reported grades as high as 0.61 percent copper, 359 ppm molybdenum, 3,160 ppb gold, 0.23 percent zinc, 0.43 percent arsenic, 236 ppm antimony, and 310 ppm tungsten, mainly exoskarn zones.
  • Age = Windy Pass Prospect is inferred to be Late Cretaceous, based on isotopic age of quartz monzonite (Moll and others, 1981).

Economic information

Economic information about the deposit and operations

Development status Prospect

Comments on exploration

  • Status = Inactive

Mining district

District name McGrath

Comments on the reserve resource information

  • Reserves = None reported.

Comments on the workings information

  • Workings / Exploration = The Windy Pass Cu-Mo-(Au)-Fe skarn prospect was first reported in the literature as a result of AMRAP investigations in the Medfra quadrangle (Patton and ohers, 1980; Patton and Moll, 1983). Work by Central Alaska Gold Company from 1991 to 1994 (DiMarchi and others,1992, 1994) mapped, sampled and conducted ground geophysical surveys of the deposit. No drilling has taken place. DiMarchi and others (1992, 1994) reported values as high as 0.27 ounces/ton (8.4 ppm) gold (in quartz veins), 0.25 percent copper (in exoskarn), and 650 ppm molybdenum (in exoskarn). Clautice and others (1993) reported grades as high as 0.61 percent copper, 359 ppm molybdenum, 3,160 ppb gold, 0.23 percent zinc, 0.43 percent arsenic, 236 ppm antimony, and 310 ppm tungsten from mainly exoskarn zones.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF MD013

Bibliographic references

  • Deposit

    Patton, W.W., Jr., Moll, E.J., Dutro, J.T., Jr., Silberman, M.L., and Chapman, R.M., 1980, Preliminary geologic map of Medfra quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-811-A, 1 sheet, scale l:250,000.

  • Deposit

    Dutro, T.T. Jr., and Patton,W.W. Jr., 1982, New Paleozoic Formations in the northern Kuskokwim Mountains, west-central Alaska: U.S. Geological Survey Bulletin 1529-H, p. H13-H22.

  • Deposit

    Patton, W.W., Jr., and Moll, E.J., 1983, Mineral resource assessment map of the Medfra quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-811-G, 3 sheets, scale 1:250,000.

  • Deposit

    DiMarchi, J.J., Weglarz, T.B., Freeman, L.K., Nicholson, L.C., and Barker, J.C., 1992, Annual Report for 1992--Doyon Option Lands, Block 10: ASA Inc. Report, 121 pages (Report held by Doyon Ltd., Fairbanks, Alaska.)

  • Deposit

    DiMarchi, J.J., Weglarz, T.B., Adams, D.D., Huber, J., and West, A.W., 1994, Annual Report for 1993--Doyon Option Lands, Volume 1: ASA Inc. Report, 187 p. (Report held by Doyon Ltd., Fairbanks, Alaska.)

  • Deposit

    Clautice, K.H., Bowman, N.D., Clough, J.G., Gilbert, W.G., Kline, J.T., Smith, T.E., and Blodgett, R.B., 1993, Land selection Unit 8 (Kantishna River, Ruby, and Medfra quadrangles): References, lead isotope, geochemical and major oxide data: Alaska Division of Geological and Geophysical Surveys, 42 p., 1 sheet, scale 1:250,000.

Comments on the references

  • Primary Reference = DiMarchi and others, 1992

General comments

Subject category Comment text
Deposit Model Name = Copper skarn deposits (Cox and Singer, 1986; model no. 18b)
Deposit Other Comments = See Nixon Fork Mine (MD062). The Windy Pass prospect is on land selected or owned by Doyon Ltd. For additional information, contact Doyon Ltd. at 210 1st Ave., Fairbanks, Alaska 99701.

Reporter information

Type Date Name Affiliation Comment
Reporter 05-JUN-98 Bundtzen, T.K. Pacific Rim Geological Consulting