Sukakpak Mountain

Prospect in Alaska, United States with commodities Silver, Gold, Antimony, Mercury, Molybdenum

Sections on this page

Identification information
Geographic coordinates
Site location context
Geographic areas
Commodities
Materials information
Alteration
Host and associated rocks
Nearby scientific data
Economic information about the deposit and operations
Mining district
Links to other databases
Bibliographic references
General comments
Reporter information

Geologic information

Identification information

Deposit ID	10001415
MRDS ID	A012160
Record type	Site
Current site name	Sukakpak Mountain
Related records	10281886

Geographic coordinates

Geographic coordinates:	-149.73334, 67.58971 (WGS84)
Relative position	The Sukakpak Mountain prospect is at an elevation of about 3,600 feet on the south flank of Sukakpak Mountain about 1/2 mile south of the summit (SE1/4 sec. 15, T. 32 N., R. 10 W., of the Fairbanks Meridian). The location is accurate within a 1/4-mile radius.

Site location context

Political divisions (FIPS codes)

Yukon-Koyukuk(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Chandalar C-6(quadrangle 1:63,360 scale)

Chandalar N(quadrangle 1:100,000 scale)

Chandalar(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Alaska(hydrologic region)

Federal lands

BLM(Federal land areas administered by BLM)

Geographic areas

Country	State
United States	Alaska

Commodities

Commodity	Importance
Silver	Primary
Gold	Primary
Antimony Critical	Primary
Mercury	Secondary
Molybdenum	Secondary

Materials information

Materials	Type of material
Cinnabar	Ore
Gold	Ore
Molybdenite	Ore
Stibnite	Ore
Tetrahedrite	Ore
Calcite	Gangue
Quartz	Gangue

Alteration

(Local) There is little gossan or other weathering associated with the veins and almost no wallrock alteration. The stibnite weathers to yellow stibconite (Sb3O6(OH)) and red kermesite (Sb2S2O).

Host and associated rocks

Host or associated Host

Rock type

Stratigraphic age (youngest) Devonian

Nearby scientific data

(1)	-149.73334, 67.58971	ListMap

Economic information

Comments on the geologic information

Geologic Description = The Sukakpak Mountain prospect consists of 2 or 3(?) quartz-stibnite-gold veins exposed intermittently for 1 kilometer in and near a high-angle fault at the contact between Devonian and Silurian(?) Skajit Limestone and underlying Ordovician to Cambrian(?) graphitic quartz-, chlorite-, calcareous schists intruded by metabasite dikes (Dillon, 1982). The veins occur in the Skajit Limestone along thin schist layers or along the contact between marble and the underlying schist unit. The veins consist of early sulfide-poor (traces of chalcopyrite and tetrahedrite) and later stibnite- and gold-bearing quartz. The stibnite occurs as euhedral crystals in amounts ranging from less than 10 percent to more than 50 percent of the vein. Stibnite crystals as long as 8 inches are present. Gold occurs as small cubes and as wire and flakes in fractures within the veins along with stibnite, quartz, and graphite. The veins exhibit characteristics of open-space filling that include crystalline stibnite and cockscomb quartz crystals. Eleven channel samples of the veins (Huber, 1988) showed values of 0.1 to 43 ppm Au, less than 1 to 16.5 ppm Ag, and 0.23 percent to 34 percent Sb. Thirteen additional channel samples (Dillon and Reifenstuhl, 1990) showed an average grade of 0.44 ounce of gold per ton and 17.4 percent Sb. Nokleberg (1987) reported grab samples (presumably of vein material) with as much as 560 grams of gold per ton, 4.5 grams of silver per ton, 54 percent Sb, and 1.7 percent Mo; 0.5 percent Hg was also reported. Some reports (Dillon, 1982; Nokleberg, 1987) have suggested the presence of cinnabar and possibly molybdenite, but Huber's analyses showed little evidence of elements other than Au and Sb. Huber also noted the presence of kermesite (Sb2S2O), a red mineral that resembles cinnabar, as a weathering product of the stibnite.? Huber described two veins and referred to them as the lower and upper veins. The lower vein, exposed by trenching on the schist-marble contact, consists of an 8-inch vein and eight small veinlets that trend N70W and dip 45 degrees northeast. They are exposed along strike for a distance of approximately 20 feet and terminate at both ends in black clay- and calcite-rich fault gouge. The veinlets, 1/2 to 4 inches in width and 1 to 3 feet in length, are in thin schist layers in the marble. The footwall of the lower vein is pyritic, graphite-quartz schist, and the hangingwall is black graphitic marble. The upper vein is entirely within the Skajit Limestone. It strikes N56E and dips 70 degrees to 90 degrees southeast. It is 1 to 6 feet in width and is exposed for nearly 400 feet along strike and for 150 vertical feet.
Age = Middle Cretaceous based on arguments by Dillon (1982) that the age of emplacement of the gold-bearing quartz veins of the Koyukuk and Chandalar districts was between the Neocomian metamorphism of the Devonian host rocks and their erosional unroofing and cooling in Albian time.
Age = Host rock is Devonian.

Economic information about the deposit and operations

Development status	Prospect
Commodity type	Metallic

Comments on exploration

Status = Inactive

Mining district

District name	Koyukuk

Comments on the workings information

Workings / Exploration = Surface sampling with some trenching. The occurrence was recognized in the early 1980s, although apparently there are old workings on vein outcrops and evidence of drift mining on Discovery Creek (CH077).

Reference information

Links to other databases

Agency	Database name	Acronym	Record ID	Notes
USGS	Mineral Resources Data System	MRDS	A012160
USGS	Alaska Resource Data File	ARDF	CH076

Bibliographic references

Deposit

Dillon, J.T., 1982, Source of lode and placer gold deposits of the Chandalar and upper Koyukuk Districts: Alaska Division of Geological and Geophysical Surveys Open-File Report 158, 25 p., 1 sheet, scale 1:250,000.
Deposit

Mosier, E.L., Cathrall, J.B., Antweiler, J.C., Tripp, R.B., Lueck, L., and Eakins, G.R., 1987, Gold occurrences and characteristics in the Chandalar-Koyukuk area, in Albanese, M.A. and Campbell, B.W., eds., Proceedings of 9th Annual Alaska Conference on Placer Mining: Alaska Division of Geological and Geophysical Surveys Miscellaneous Paper 9, p. 45-53.
Deposit

Nokleberg, W.J., Bundtzen, T.K., Berg, H.C., Brew, D.A., Grybeck, D.J., Robinson, M.S., Smith, T.E., and Yeend, W., 1987, Significant metalliferous lode deposits and placer districts of Alaska: U.S. Geological Survey Bulletin 1786, 104 p.
Deposit

Huber, J.A., 1988, The geology and mineralization of the Sukakpak Mountain area, Brooks Range, Alaska: Fairbanks, Alaska, University of Alaska Fairbanks, M.Sc. thesis, 81 p.
Deposit

Nokleberg, W.J., Bundtzen, T.K., Berg, H.C., Brew, D.A., Grybeck, Donald, Robinson, M.S., Smith, T.E., and Yeend, Warren, 1988, Metallogeny and major mineral deposits of Alaska: U.S. Geological Survey Open-File Report 88-73, 97 p., 2 plates, scale 1:5,000,000.
Deposit

Dillon, J.T., Lamal, K.K., and Huber, J.A., 1989, Gold deposits in the upper Koyukuk and Chandalar mining districts, in Mull, C.G., and Adams, K.E., eds., Bedrock geology of the eastern Koyukuk Basin, central Brooks Range, and east-central Arctic Slope along the Dalton Highway, Yukon River to Prudhoe Bay, Alaska: Alaska Division of Geological and Geophysical Surveys Guidebook 7, 2 v., 309 p., 2 sheets, scale 1:125,000 and 1:2,851,200.
Deposit

Dillon, J.T., and Reifenstuhl, R.R., 1990, Geologic map of the Wiseman B-1 quadrangle, southcentral Brooks Range, Alaska: Alaska Division of Geological and Geophysical Surveys Professional Report 101, 1 sheet, scale 1:63,360.
Deposit

Nokleberg, W.J., Bundtzen, T.K., Grybeck, D.J., Koch, R.D., Eremin, R.A., Rozenblum, I. S., Sidorov, A.A., Byalobzhesky, S.G., Sosunov, G.M., Shpikerman, V.I., Gorodinsky, M.E., 1993, Metallogenesis of mainland Alaska and the Russian Northeast: U.S. Geological Survey Open-File Report 93-0339, 3 sheets, 230 p.
Deposit

Dillon, J.T., Reifenstuhl, R.R., and, Harris, G.W., 1996, Geologic map of the Chandalar C-5 quadrangle, southeastern Brooks Range, Alaska: Alaska Division of Geological and Geophysical Surveys Professional Report 104, 1 sheet, scale 1:63,360.
Deposit

Nokleberg, W.J., Bundtzen, T.K., Dawson, K.M., Eremin, R.A., Goryachev, N.A., Koch, R.D., Ratkin, V.V, Rozenblum, I.S., Shpikerman, V.I., Frolov, Y.F., Gorodinsky, M.E., Melnikov, V.D., Diggles, M.F., Ognyanov, N.V., Petrachenko, E.D., Petrochenko, R.I., Pozdeev, A.I., Ross, K.V., Wood, D.H., Grybeck, D., Khanchuck, A.I., Kovbas, L.I., Nekrasov, I.Y., and Sidorov, A.A., 1996, Significant metalliferous and selected non-metalliferous lode mineral deposits and placer districts, and for metallogenesis of the Russian Far East, Alaska, and the Canadian Cordillera: U.S. Geological Survey Open-File Report 96-513-B, 385 p.; U.S. Geological Survey Open-File Report 96-513-B, 385 p. (CD-ROM format).

Comments on the references

Primary Reference = Huber, 1988

General comments

Subject category	Comment text
Deposit	Model Name = Sb-Au vein deposit (Nokleberg and others, 1987)
Deposit	Other Comments = This prospect is in the Alaska pipeline inner corridor and is not open to mineral entry. It probably is the source of placer Au in Discovery Creek (CH077).? Analytical results from assay of selected high-grade grab samples: 5 to 38 ppm Cu, less than 1 to 30 ppm Pb, 2 to 109 ppm Zn, as much as 27.2 ppm Au, as much as 4.5 ppm Ag, as much as 17,000 ppm Mo, 0.35 to 62 percent Sb, and up to or more than 5,000 ppm Hg, (Dillon, 1982, table 2, p. 17).

Subject category

Comment text

Deposit

Model Name = Sb-Au vein deposit (Nokleberg and others, 1987)

Deposit

Other Comments = This prospect is in the Alaska pipeline inner corridor and is not open to mineral entry. It probably is the source of placer Au in Discovery Creek (CH077).? Analytical results from assay of selected high-grade grab samples: 5 to 38 ppm Cu, less than 1 to 30 ppm Pb, 2 to 109 ppm Zn, as much as 27.2 ppm Au, as much as 4.5 ppm Ag, as much as 17,000 ppm Mo, 0.35 to 62 percent Sb, and up to or more than 5,000 ppm Hg, (Dillon, 1982, table 2, p. 17).

Reporter information

Type	Date	Name	Affiliation	Comment
Reporter	17-NOV-1999	J.M. Britton	U.S. Geological Survey

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.

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Authoritative Alaska resources

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