Unnamed (headwaters of Montana Creek)

Prospect, Inactive

Alternative names

MC

Commodities and mineralogy

Main commodities Au
Other commodities Sn; W
Ore minerals pyrite; pyrrhotite
Gangue minerals amphibole; diopside; epidote; garnet; quartz; wollastonite

Geographic location

Quadrangle map, 1:250,000-scale MZ
Quadrangle map, 1:63,360-scale A-2
Latitude 65.2301
Longitude -153.524
Nearby scientific data Find additional scientific data near this location
Location and accuracy This lode prospect, informally called the Montana Creek prospect, is near the headwaters of Montana Creek, about 7 miles north of the mouth of the creek on the Yukon River. At least 90 mining claims were located at this site in the late 1970's (Kardex file 047-016; unpublished record, Alaska Division of Mining, Land & Water). The center of the claim block is in the northeast quarter of section 16, T. 3 S., R. 26 E., Kateel River Meridian. The location is accurate.

Geologic setting

Geologic description

The rocks in the vicinity of the Montana Creek prospect are Paleozoic quartz-feldspar-biotite gneiss and biotite-bearing quartzite, and subordinate quartz-biotite schist, marble, and calc-silicate rock (Patton and others, 1977). The gneiss is garnetiferous, locally contains sillimanite, and includes bodies of gneissic and massive quartz monzonite. The gneiss and quartzite grade into pelitic schist containing small bodies of marble and greenstone to the east, and into an elongate body of marble parallel to Montana Creek near the prospect. The prospect is about 1 mile east of a small, porphyritic, biotite quartz monzonite stock east of Gold Mountain. The stock is altered and slightly cataclastic. Patton and others (1977) correlate it with the Lower Cretaceous Melozitna pluton, which has a K-Ar date of 111+/-3 Ma.
WGM, Inc. discovered mineralization at this prospect while conducting a regional geochemical sampling program from 1975 to 1977 on Doyon land block 18 (DiMarchi and others, 1991). Their panned-concentrate samples from Montana Creek contained as much as 18 parts per million (ppm) tin and 150 ppm tungsten, but there were no anomalous gold values. Followup panned-concentrate samples contained up to 2 ppm gold, 160 ppm tin, and 290 ppm tungsten. Pyritic quartz vein float was assayed but did not contain significant metal values.
In 1978, Resource Associates of Alaska, Inc. located 90 mining claims, known as the MC claims, under an exploration agreement with Houston Oil & Minerals Corp. (Kardex file 047-016; unpublished record, Alaska Division of Mining, Land & Water). Exploration work in 1979 and 1980 included geological, geochemical, and geophysical surveys on the claims and surrounding area. Geological work consisted of mapping structures, alteration, mineralization, and the bedrock along ridge crests, stream valleys, and other areas with rock outcrops. The mineralization was observed principally in metamorphic and bedded rocks, including sandy carbonate, that strike north and border a granitic gneiss complex. Geochemical surveys in 1979 consisted of collecting and analyzing 446 soil and rock samples on a grid with 400-foot spacing, and targeted sampling in areas of known mineralization. The exploration showed that zones of anomalous geochemical values coincide with fractures in sandy carbonate and granitic gneiss. About 13,200 feet of ground magnetic surveys indicated that areas of anomalous magnetic susceptibility coincide with pyrrhotite mineralization in garnet-bearing amphibolite (probably skarn).
The geology and mineralization at this prospect is poorly known. North Star Exploration, Inc. (1999 [DLR 99-33]) reported that it is similar to the Glacier Creek (MZ024) and Ninemile Creek (MZ026) prospects, which they interpret as sulfide-bearing, garnet-epidote-diopside-wollastonite skarn deposits.
Geologic map unit (-153.526528265686, 65.2295473602673)
Mineral deposit model W Skarn (Cox and Singer, 1986; model 14a)
Mineral deposit model number 14a
Age of mineralization Probably roughly coeval with emplacement of the Lower Cretaceous Melozitna pluton, dated by K-Ar at 111+/- 3 Ma (Patton and others, 1977).
Alteration of deposit Metasomatism of carbonate-bearing rocks.

Production and reserves

Workings or exploration
WGM, Inc. discovered mineralization at this prospect while conducting a regional geochemical sampling program from 1975 to 1977 on Doyon land block 18 (DiMarchi and others, 1991). Their panned-concentrate samples from Montana Creek contained as much as 18 parts per million (ppm) tin and 150 ppm tungsten, but there were no anomalous gold values. Followup panned-concentrate sample yielded up to 2 ppm gold, 160 ppm tin, and 290 ppm tungsten. Pyritic quartz vein float was assayed but did not contain significant metal values.
In 1978, Resource Associates of Alaska, Inc. located 90 mining claims, known as the MC claims, under an exploration agreement with Houston Oil & Minerals Corp. (Kardex file 047-016; unpublished record, Alaska Division of Mining, Land & Water). Exploration work in 1979 and 1980 included geological, geochemical, and geophysical surveys on the claims and surrounding area. Geological work consisted of mapping structures, alteration, mineralization, and the bedrock along ridge crests, stream valleys, and other areas with rock outcrops. The mineralization was observed principally in metamorphic and bedded rocks, including sandy carbonate, that strike north and border a granitic gneiss complex. Geochemical surveys in 1979 consisted of collecting and analyzing 446 soil and rock samples on a grid with 400-foot spacing, and targeted sampling in areas of known mineralization. The exploration showed that zones of anomalous geochemical values coincide with fractures in sandy carbonate and granitic gneiss. About 13,200 feet of ground magnetic surveys indicated that areas of anomalous magnetic susceptibility coincide with pyrrhotite mineralization in garnet-bearing amphibolite (probably skarn).
The geology and mineralization at this prospect is poorly known. North Star Exploration, Inc. (1999 [DLR 99-33]) reported that it is similar to the Glacier Creek (MZ024).
Indication of production None

Additional comments

The Montana Creek prospect is on land selected by Doyon, Limited. For further information, contact Doyon, Limited, 1 Doyon Place, Suite 300, Fairbanks, Alaska 99701-2941.
This site is the Montana, U.S. BLM MILS location 0020470005 (Oddenino and others, 1995; Interagency Minerals Coordinating Group, 2004).

References

References

DiMarchi, J.J., Weglarz, T.B., Dickey, C.F., Laux, D.P., Smith, M.T., Toro, J., and Kurtz, J.P., 1991, Central Alaska Gold Co. 1990 annual report, Alaska field operations - Doyon option volume 7 plates, Fortymile central, Fortymile south, mid-Yukon, Nikolai, and East Holy Cross blocks: Doyon, Ltd. Report 91-8d. (Report held by Doyon, Ltd., Fairbanks, Alaska).
Interagency Minerals Coordinating Group, 2004, Alaska Mineral Locations Database [MAS (Minerals Availability System) and MILS (Mineral Industry Location System)], http://imcg.wr.usgs.gov/dem.html (select Melozitna quadrangle).
Meinert, L.D., 1992, Skarns and skarn deposits: Geoscience Canada, v. 19, p. 145-162.
North Star Exploration Company, 1999, North Star 1998 Annual Report, Block 18, Middle Yukon, DLR 99-33 (Report held by Doyon, Limited, Fairbanks, Alaska).
Reporters G.E. Graham, D.J. Szumigala (Alaska Division of Geological and Geophysical Surveys)
Last report date 1/14/2005