Mikado mine (Mikado

Past Producer in Alaska, United States with commodities Gold, Silver, Arsenic, Lead, Antimony, Zinc

Sections on this page

Identification information
Geographic coordinates
Site location context
Geographic areas
Commodities
Materials information
Alteration
Mineral occurrence model information
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	10308805
MRDS ID	A010680
Record type	Site
Current site name	Mikado mine (Mikado
Alternate or previous names	Little Mikado, Tobin, Carter, Eclipse, Overlook, Engineers Exploration Syndicate, Idaho-Alaska Corp.)
Related records	10000494

Geographic coordinates

Geographic coordinates:	-148.25329, 67.53973 (WGS84)
Relative position	The Mikado mine is at an elevation of about 4,600 ft, approximately 1 1/2 miles southwest of Little Squaw Peak and 4 1/2 miles south-southwest of the south end of Squaw Lake near the east branch of the headwaters of Tobin Creek (SE1/4 sec. 5, T. 31 N., R. 3 W., of the Fairbanks Meridian). This location probably represents the Mikado mine portal and 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-3(quadrangle 1:63,360 scale)

Chandalar N(quadrangle 1:100,000 scale)

Chandalar C(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Alaska(hydrologic region)

Geographic areas

Country	State
United States	Alaska

Commodities

Commodity	Importance
Gold	Primary
Silver	Secondary
Arsenic Critical	Secondary
Lead	Secondary
Antimony Critical	Secondary
Zinc Critical	Secondary

Materials information

Materials	Type of material
Arsenopyrite	Ore
Galena	Ore
Gold	Ore
Pyrite	Ore
Siderite	Ore
Sphalerite	Ore
Stibnite	Ore
Quartz	Gangue

Alteration

Oxidation of vein material produces scorodite and limonite.

Mineral occurrence model information

Model code	273
USGS model code	36a
Deposit model name	Low-sulfide Au-quartz vein
Mark3 model number	27

Host and associated rocks

Host or associated Host

Rock type

Stratigraphic age (youngest) Devonian

Nearby scientific data

(1)	-148.25329, 67.53973	ListMap

Economic information

Comments on the geologic information

Geologic Description = Discovered in 1909, the Mikado vein is one of several auriferous quartz veins in an area approximately 1 mile wide and 2 1/2 miles long between the heads of Tobin and Big creeks to the south and Squaw and Little Squaw creeks to the north. In general, most of the gold-bearing quartz veins in this area are in or near steeply dipping, northwest-trending normal faults in Devonian quartz-muscovite schist, phyllite, and quartzite intruded by Devonian mafic sills and dikes (Chipp, 1970). The intrusions have been metamorphosed to greenstone or greenschist. Major structural features include large-scale northeast-trending anticlines and synclines, northeast-trending thrusts, and the northwest-trending, high-angle cross faults. The Mikado vein/fault system is described as a shear zone about 50 feet wide which contains sub-parallel, highly faulted and brecciated, steeply dipping (80 N), auriferous quartz veins up to 6 feet thick which have been exposed for over 3,000 feet along the Mikado fault (Maddren, 1913). Although the Mikado vein is said to average 6 feet in thickness over a 500-feet strike length, most of the ore shoots are discontinuous and generally are a few tens or hundreds of feet long. According to Boadway (1933), the Mikado vein in the underground workings consists of lenses of auriferous quartz, mostly on the hangingwall side of a gouge-filled fault. The vein appears to be approximately 35 inches or less in width in the upper levels and narrows to 16 inches at a depth of 99 feet. Ore shoots in the vein reportedly assayed from $37 per ton to as high as $439 per ton at $20 per ounce of gold), and one ore shoot averaged $49.50 per ton over a 35-inch width (Chipp, 1970). Drilling has intersected additional quartz in both the hangingwall and footwall of the fault. In a general description of the Chandalar gold-quartz lodes, Chipp (1970) indicated that white, crystalline to microcrystalline quartz is the dominant gangue mineral and that crystals of quartz are commonly found in small vugs. Banding in the quartz veins is produced by shearing and by elongated cavities in the veins parallel to the walls. Siderite occurs in minor amounts. Ashworth (1983) described three generations of quartz in the Mikado deposit: (1) lenses and pods of quartz plus or minus pyrite plus or minus dolomite, which are possibly pre-faulting metamorphic segregations; (2) massive, white, coarsely crystalline quartz with less than 5 percent sulfides and trace gold; and (3) 'main stage' quartz, which is fine grained, white, and in places vuggy. The sulfide assemblage in main stage quartz consists in decreasing order of abundance of arsenopyrite, galena, sphalerite, stibnite, and pyrite. Native gold, as flakes or wires, is common in the Mikado and typically is along the borders of sulfide grains or in quartz near sulfides. Sulfides generally form less than 5 percent of the veins. Early workers postulated the source of the gold-quartz mineralization to be small granitic intrusives, based largely on the presence of monazite and rutile in the placers (Mertie, 1925). Chipp (1970) suggested that there may be a genetic relationship with the the larger greenstone bodies as well. The genesis of these gold deposits is still in question, although various workers have hypothesized some genetic link to a variety of felsic and mafic igneous rocks from which the gold was remobilized during metamorphism (Mertie, 1925; Boadway, 1933; Chipp, 1970; Dillon, 1982).
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.

Economic information about the deposit and operations

Development status	Past Producer
Commodity type	Metallic

Comments on exploration

Status = Inactive

Mining district

District name	Chandalar

Comments on the production information

Production Notes = The amount of gold produced from the Mikado vein prior to 1960 is unknown; however, a small stamp mill was constructed on Spring Creek by 1913 to process ore from the Mikado and Little Squaw mines. Production between 1960 and 1979 was reported to be approximately 1,000 oz Au and 200 oz Ag (Cobb and Cruz, 1983). In 1979 the Little Squaw Gold Mining Co. resumed development and seasonal production, and the ore was processed through a cyanide leach-flotation plant on Tobin Creek at a rate of 100 to 125 tons per day (Bundtzen and others, 1984). Production during 1981 was reported as 4,000 tons of ore worth $1.6 million (Bundtzen and others, 1982). In 1983 it was estimated that 10,000 oz of gold had been recovered during the last several years (1979-1982?) (Bundtzen and others, 1984). Lode production apparently ceased in 1983 due to lack of developed reserves and the high cost of the remote operations.

Comments on the reserve resource information

Reserves = Various reserve figures, which generally do not define reserves for specific deposits, have been published for the Chandalar area lode properties. Some of these figures are as follows: Bundtzen and others (1982) reported that in 1979 the Mikado property had proven reserves of 30,000 tons of 1 oz of gold per ton, and Nokleberg and others (1987) noted 12,000 tonnes grading 75 grams of gold per tonne at the Mikado and Little Squaw mines. An inferred lode reserve for the Chandalar district lodes of 45,000 tons with a grade of 2 oz of gold per ton was reported as late as 1997 (Swainbank and others, 1998). Heiner and Wolff (1968) reported proved reserves estimated to be $2,000,000 with the ore valued at $85 per ton. Baggs and others (1988) reported 13,600 metric tons of measured, 4,500 metric tons indicated and 18,200 metric tons inferred at a grade of 85.2 grams of gold per metric ton as of 1980.

Comments on the workings information

Workings / Exploration = Maddren (1913) reported open cuts that exposed auriferous quartz in six places over a strike length of 3,000 feet. Underground workings, including a 100-foot shaft and 160-foot adit, reportedly were completed by 1913. The underground workings were reopened in 1960, and an additional 600 feet of new workings were driven. An additional 800 feet was driven in 1962-63. An unknown amount of work was done in late 1960s, and again in the late 1970s and early 1980s (Bundtzen and others, 1982). Some bulldozer trenching was completed on veins in the area in 1962.

Reference information

Links to other databases

Agency	Database name	Acronym	Record ID
USGS	Alaska Resource Data File	ARDF	CH045
USGS	Mineral Resources Data System	MRDS	A010680
USGS	Mineral Resources Data System	MRDS	A012558

Bibliographic references

Deposit

Maddren, A.G., 1913, The Koyukuk-Chandalar region, Alaska: U.S. Geological Survey Bulletin 532, 119 p.
Deposit

Brooks, A.H., 1914, Mineral resources of Alaska in 1913: U.S. Geological Survey Bulletin 592, p. 340-341.
Deposit

Mertie, J.B., Jr., 1925, Geology and gold placers of the Chandalar district, in Brooks, A.H., and others, Mineral resources of Alaska, report on progress of investigations in 1923: U.S. Geological Survey Bulletin 773, p. 215-263.
Deposit

Thompson, G.L., 1925, Report on the property of the Chandalar Gold Company: Alaska Territorial Department of Mines Miscellaneous Report 31-1, 18 p.
Deposit

Reed, I.M., 1927, Report on some of the quartz prospects of the Chandalar district: Alaska Territorial Department of Mines Miscellaneous Report 31-2, 4 p.
Deposit

Stanford, J.V., 1931, Report on Little Squaw, Bonanza, and Mikado groups of claims, Chandalar, Alaska: Alaska Territorial Department of Mines Miscellaneous Report 31-5, 10 p.
Deposit

Boadway, E.A., 1932, Report on Sulzer properties, Chandalar, Alaska: Alaska Territorial Department of Mines Miscellaneous Report 31-6, 23 p., 4 sheets.
Deposit

Boadway, E.A., 1933, Report on Mikado and Little Squaw veins, Chandalar, Alaska: Alaska Territorial Department of Mines Miscellaneous Report 31-7, 37 p.
Deposit

Smith, P.S., 1934, Mineral industry of Alaska in 1932: U.S. Geological Survey Bulletin 857-A, p. 1-91.
Deposit

Anderson, Eskil, 1944, Petrographic descriptions of rocks collected during 1944 field investigation in north-west Alaska, and lists of ore and rock samples and placer concentrates collected in northwestern and interior Alaska during 1945 field season: Alaska Territorial Department of Mines Miscellaneous Report 195-28, 76 p.
Deposit

Saunders, R.H., 1959, Silver-lead occurrences in the Fairbanks district: Alaska Territorial Department of Mines Miscellaneous Report 194-18, 19 p., 2 maps, scale 1:63,360.
Deposit

Saunders, R.H., 1962, Report on exploration in the Chandalar district: Alaska Territorial Department of Mines Prospect Evaluation 31-3, 5 p.
Deposit

Heiner, L.E., and Wolff, E.N., eds., 1968, Mineral resources of northern Alaska, Final report, submitted to the NORTH Commission: Mineral Industry Research Laboratory, University of Alaska, Report 16, 306 p.
Deposit

Chipp, E.R., 1970, Geology and geochemistry of the Chandalar area, Brooks Range, Alaska: Alaska Division of Geological and Geophysical Surveys Geologic Report 42, 39 p., 1 sheet, scale 1:36,000.
Deposit

Brosgi, W.P., and Reiser, H.N., 1972, Geochemical reconnaissance in the Wiseman and Chandalar districts and adjacent region, southern Brooks Range, Alaska: U.S. Geological Survey Professional Paper 709, 21 p.
Deposit

Cobb, E.H., 1972, Metallic mineral resources map of the Chandalar quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-457, 1 sheet, scale 1:250,000.
Deposit

Cobb, E.H., 1973, Placer deposits of Alaska: U.S. Geological Survey Bulletin 1374, 213 p.
Deposit

Cobb, E.H., 1976, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Chandalar and Wiseman quadrangles, Alaska: U.S. Geological Survey Open-File Report 76-340, 205 p.
Deposit

Grybeck, D.J., 1977, Known mineral deposits of the Brooks Range, Alaska: US Geological Survey Open-File Report 77-166C, 41 p., 1 sheet, scale 1:1,000,000.
Deposit

DeYoung, J.H., Jr., 1978, Mineral resources map of the Chandalar quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-878-B, 2 sheets, scale 1:250,000.
Deposit

Reiser, H.N., Brosgi, W.P., De Young, J.H., Jr., Marsh, S.P., Hamilton, T.D., Cady, J.W., and Albert, N.R.D., 1979, The Alaskan Mineral Resource Assessment Program: Guide to information contained in the folio of geologic and mineral resource maps of the Chandalar quadrangle, Alaska: U.S. Geological Survey Circular 758, 23 p.
Deposit

Bundtzen, T.K., Eakins, G.R., and Conwell, C.N., 1982, Review of Alaska mineral resources 1981: Alaska Division of Geological and Geophysical Surveys Annual Report 1981, 48 p., 2 sheets, scale 1:3,000,000.
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

Bundtzen, T.K., Eakins, G.R., and Conwell, C.N., 1982, Alaska mineral resources 1981-82: Alaska Division of Geological and Geophysical Surveys Annual Report 1981-82, 153 p., 4 sheets, scale 1:2,500,000.
Deposit

Cobb, E.H., and Cruz, E.L., 1983, Summaries of data and lists of references to metallic and selected nonmetallic mineral deposits in the Chandalar quadrangle, Alaska: U.S. Geological Survey Open-File Report 83-278, 91 p.
Deposit

Ashworth, K.K., 1983, Genesis of gold deposits at the Little Squaw mines, Chandalar mining district, Alaska: Bellingham, Washington, Western Washington University, M.Sc. thesis, 98 p.
Deposit

Eakins, G.R., Bundtzen, T.K., Robinson, M.S., Clough, J.G., Green, C.B., Clautice, K.H., and Albanese M.A., 1983, Alaska's mineral industry, 1982, Alaska Division of Geological and Geophysical Surveys Special Report 31, 63 p.
Deposit

Bundtzen, T.K., Eakins, G.R., Clough, J.G., Lueck, L.L., Green, C.B., Robinson, M.S., and Coleman, D.A., 1984, Alaska's Mineral Industry, 1983: Alaska Division of Geological and Geophysical Surveys Special Report 33, 56 p.
Deposit

Eakins, G.R., Bundtzen, T.K., Lueck, L.L. Green, C.B., Gallagher, J.L., and Robinson, M.S., 1985, Alaska mineral industry, 1984: Alaska Division of Geological and Geophysical Surveys Special Report 38, 57p.
Deposit

Bundtzen, T.K., Green, C.B., Deagen, J., and Daniels, C.L., 1987, Alaska's mineral industry, 1986: Alaska Division of Geological and Geophysical Surveys, Special Report 40, 68 p.
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

Baggs, D.W., Northam, M.J., Meyer, M.P., and Maas, K.M., 1988, Selected significant mineral deposits in Alaska, a minerals availability system overview: U.S. Bureau of Mines Information Circular 9177, 124 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

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

Swainbank, R.C., Clautice, K.C., and Nauman, J.L., 1998, Alaska's Mineral Industry 1997: Alaska Division of Geological and Geophysical Surveys Special Report 52, 65 p.
Deposit

Bundtzen, T.K., Green, C.B., Peterson, R.J., and Seward, A.F., 1988, Alaska's mineral industry, 1987: Alaska Division of Geological and Geophysical Surveys Special Report 41, 69 p.
Deposit

Bundtzen, T.K., Swainbank, R.C., Wood, J.E., Clough, A.H., 1991 (1992), Alaska's Mineral Industry 1991: Alaska Division of Geological & Geophysical Surveys, Special Report 46, 89 p.
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).
Deposit

Reed, I.M., 1930, Report on the Little Squaw area of the Chandalar mining district: Alaska Territorial Department of Mines Miscellaneous Report 31-4, 18 p.
Deposit

Williams, J.A., 1960, Report of the Division of Mines and Minerals for the year 1960: Alaska Territorial Department of Mines Annual Report 1960, 88 p.

Comments on the references

Primary Reference = Chipp, 1970; Ashworth, 1983

General comments

Subject category	Comment text
Deposit	Model Name = Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)
Deposit	Other Comments = There has been active exploration and small production up to the present. Recent literature, and especially news notes, may confuse the Little Squaw and Mikado mines because the Mikado is owned by Little Squaw Mining Co. References to the Little Squaw property thus may refer to either the Little Squaw Mine, the Mikado mine, or both. The names Idaho-Alaska Corp. and Engineers Exploration Syndicate associated with this property refer to the transaction in 1932 in which the Idaho-Alaska Corp. took over the leases and options formerly held by the Engineers Exploration Syndicate on various properties in the Chandalar district.

Subject category

Comment text

Deposit

Model Name = Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a)

Deposit

Other Comments = There has been active exploration and small production up to the present. Recent literature, and especially news notes, may confuse the Little Squaw and Mikado mines because the Mikado is owned by Little Squaw Mining Co. References to the Little Squaw property thus may refer to either the Little Squaw Mine, the Mikado mine, or both. The names Idaho-Alaska Corp. and Engineers Exploration Syndicate associated with this property refer to the transaction in 1932 in which the Idaho-Alaska Corp. took over the leases and options formerly held by the Engineers Exploration Syndicate on various properties in the Chandalar district.

Reporter information

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

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