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Cleary Hill

Past Producer in Livengood county in Alaska, United States with commodities Gold, Silver, Copper, Lead, Antimony, Tungsten, Zinc
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Geologic information

Identification information

Deposit ID 10309037
MRDS ID A010678
Record type Site
Current site name Cleary Hill
Alternate or previous names Summit, Cleary, Freegold

Geographic coordinates

Geographic coordinates: -147.43596, 65.06668 (WGS84)
Relative position The coordinates given are near the Cleary Hill Mine marked on the Livengood (A-1) quadrangle; SW1/4SW1/4 sec. 19, T. 3 N., R. 2 E., of the Fairbanks Meridian. The mine is east of Bedrock Creek, a tributary of Cleary Creek.
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Geographic areas

Country State County
United States Alaska Livengood

Commodities

Commodity Importance
Gold Primary
Silver Secondary
Copper Secondary
Lead Secondary
Antimony Secondary
Tungsten Secondary
Zinc Secondary

Materials information

Materials Type of material
Arsenopyrite Ore
Galena Ore
Jamesonite Ore
Scheelite Ore
Tetrahedrite Ore
Stibnite Ore
Sphalerite Ore
Silver Ore
Pyrite Ore
Gold Ore
Covellite Ore
Boulangerite Ore
Chalcopyrite Ore
Quartz Gangue

Alteration

  • Quartz, sericite and ankerite.

Nearby scientific data

(1) -147.43596, 65.06668
ListMap

Comments on the geologic information

  • Geologic Description = The Cleary Hill mine was the largest lode gold producer in the Fairbanks mining district, prior to the first production from the Fort Knox gold mine in 1996. The average grade of gold produced was approximately 1.3 ounces of gold per ton. Recent drilling in the 1990's has shown that the Cleary Hill mine still has an approximate resource of 100,000 ounces of gold with a grade of 0.81 ounces of gold per ton. In the early 1900's, gold was reported to be found in quartz veins within schist with quartz stringers (Prindle, 1910). Visible gold was found in quartz veins that were largely free of sulfides (Smith, 1913; B 525). The principle vein averages about 1 foot in thickness with a maximum thickness of about 3 feet. There are smaller, similar, parallel veins in both the hanging and footwalls; the veins are crushed, cross the foliation of schist country rock, and are complexly faulted (Smith, 1913; B 525). The Cleary Hill Mine is hosted in mafic volcanics, quartzites and quartz m uscovite schists on the north flank of the Cleary antiform (Freeman and others, 1998). The Cleary Hill vein strikes N 70-80 W and dips 45 to 70 S. The dip of the vein varies according to the host rock, with steeper dips in more competent rock units and shallow dips in less competent rock units (Freeman and others, 1998). The mine consisted of over six levels that produced ore from quartz veins that contained coarse free gold, and trace arsenopyrite, pyrite, boulangerite, and tetrahedrite. Higher grade intervals have gold values from the hundreds to the thousands of ounces of gold per ton. These intervals are commonly associated with acicular needles and felted masses of boulangerite and jamesonite, in white to gray quartz veins that are 1 to 5 feet thick (Freeman and others, 1998). . During the 1986 field season, the mine waste dumps of the Cleary Hill mine were examined and grab samples were collected by Fairbanks Exploration Inc. (Fairbanks Exploration Inc., unpublished repor t, 1986). Quartz vein samples on the Penrose and Upper adit dumps are associated with chlorite-actinolite schists of mafic volcanic origin, typical of the the lower third of the Cleary Sequence. Dump samples contained arsenopyrite, pyrite, stibnite, jamesonite, native gold, and minor scheelite hosted by quartz-bearing shear zones and stockworks with thin argillized selvages. Significant ankerite occurs in some shear zones and weathers to a bright ocherous, red color. Visible gold is usually associated with jamesonite needles and rosettes similar to mineralization in the Christina adit (ARDF no. LG146) and Nordale adit of the Homestake mine (ARDF no. LG157). Up to one-half percent scheelite is finely disseminated in chlorite-actinolite schist and less commonly forms coarser grained crystal aggregates in sulfide-free quartz shear zones. Gold values vary up to 0.558 ounces of gold per ton and appear to be higher in samples of siliceous exhalite, metarhyolite tuff and carbonaceous q
  • Geologic Description = uartzite from the lower production dumps at the mine. Reserve estimates of the waste dump made by Fairbanks Exploration Inc. in 1988 indicated the Cleary Hill mine dumps contained 71,176 tons of rock grading 0.159 ounces of gold per ton and 0.099 ounces of silver per ton (Fairbanks Exploration Inc., unpublished report, 1987; Fairbanks Exploration Inc., unpublished report, 1988). Reverse circulation drilling at the Cleary Hill Mine in late 1996 encountered at least two vein systems with values of more than 0.5 ounces of gold per ton over narrow widths below the old underground workings (Freeman and others, 1997). . Complete production records are not available for the Cleary Hill mine, however, existing published and private records indicate the Cleary Hill mine produced more than 100,000 fine ounces of gold from approximately 77,000 tons of material with an average grade of 1.3 ounces of gold per ton (Porterfield and Croff, 1986; Metz and others, 1987). This ranks the Cleary Hill mine as the largest lode gold producer in the Fairbanks Mining District, prior to the development of the Fort Knox mine. Recent drilling shows that Cleary Hill Mine, in addition to a 100,000-ounce resource grading 0.81 ounces of gold per ton, has potential for bulk tonnage, lower-grade material in the footwall of the high-grade veins (Swainbank and others, 1998)

Economic information

Economic information about the deposit and operations

Development status Past Producer
Commodity type Metallic

Comments on exploration

  • Status = Inactive

Mining district

District name Fairbanks

Comments on the production information

  • Production Notes = The first recorded production from the Cleary Hill mine was on February 9, 1910, when a five-ton lot was sent to the Tacoma, Washington, smelter and returned an average grade of 22.25 ounces of gold per ton (Times Publishing Company, 1912). On September 7, 1910, a 17-ton lot of ore from the Free Gold claim averaged 8.61 ounces of gold per ton. An additional 75 tons of ore was shipped to the Chena mill in Fairbanks in November, 1910, followed by a 100 ton lot sent to the Chena mill in early 1911. The grade of this material is unknown but reportedly paid for all past development work and a new stamp mill (Cunningham, 1912). On June 3, 1912, the Alaska Citizen, a Fairbanks newspaper, reported that 147 tons of ore from the Cleary Hill mine were milled at the Chena mill in 1911. The Cleary Hill mine operated 365 days and the mill operated for 350 days in 1914 and produced an estimated 5,950 tons of ore from 1,800 feet of productive lode (Brooks and others, 1914). Up through 1915, the Cleary Hill mine had produced approximately 29,000 fine ounces of gold from an estimated 17,000 tons of ore averaging 1.69 ounces of gold per ton (Stewart, 1922). Production from 1929 to the end of 1931 was 19,000 ounces from 9,800 tons grading 1.94 ounces of gold per ton (Hill, 1933). The high grades were derived from the Bankers stope between the Penrose and Upper adits. Total production from the mine was estimated at $1,000,000 in gold, or 48,379 ounces, through 1930 (Pilgrim, 1931). Pilgrim (1932) stated that in 1931 the Cleary Hill mine was the largest producer in the district and fourth largest lode producer in Alaska. The Cleary Hill mine remained the largest producer in the district in 1934 and 1935 due to additional production from the Main shaft and addition of a flotation circuit in the mill which increased recovery (Smith, 1936; Smith, 1937). Production from the Cleary Hill mine was interrupted in 1936 when a fire destroyed the mill and power plant (Smith, 1938). Production levels increased in 1937 due to the more efficient nature of the new mill installed after the fire (Smith and Mertie, 1941). A total of 2,085 tons of ore with an average grade of $80 per ton in gold (2.3 ounces of gold per ton) was milled in 1938 (Reed, 1939). In 1942, the War Powers Act Limitation Order L208 banned all non-essential mining in the United States, thereby forcing the closure of the Cleary Hill mine. Shortly after the Cleary Hill mine was closed, a 5 ton lot of high grade stibnite ore was shipped to Fairbanks for sale to the federal government (Joesting, 1943). This material was taken from a fault intersection just above the Main adit (Killeen and Mertie, 1951). A small amount of ore was mined by Doug Jackson and Earl Beistline during 1949 and 1950 from previously worked areas above the Main adit (Saarela, 1950; Wedow and others, 1954). The Cleary Hill mill was rehabilitated and used for custom milling by Adolph, Rudy and Grac e Vetter in 1956. Complete production records are not available for the Cleary Hill mine, however, existing published and private records indicate the Cleary Hill mine produced in excess of 100,000 fine ounces of gold from approximately 77,000 tons of material at an average grade of 1.3 ounces of gold per ton (Porterfield and Croff, 1986; Metz and others, 1987). This ranks the Cleary Hill mine as the largest lode gold producer in the Fairbanks Mining District, prior to the development of the Fort Knox mine.

Comments on the reserve resource information

  • Reserves = Waste dump reserve estimates made by Fairbanks Exploration Inc. in 1988 indicated the Cleary Hill mine dumps contained 71,176 tons of rock grading 0.159 ounces of gold per ton and 0.099 ounces of silver per ton (Freeman and others, 1987; Freeman and others, 1988).. Recent drilling shows that Cleary Hill Mine, in addition to a 100,000-ounce resource grading 0.81 ounces of gold per ton, has potential for bulk tonnage, lower-grade material in the footwall of the high-grade veins (Swainbank and others, 1998).

Comments on the workings information

  • Workings / Exploration = Mineralization was first discovered on the Freegold claim prior to 1910, near the juncture of Cleary and Bedrock Creeks. Shortly after discovering the rich surface outcrops of the Cleary Hill lode (selected samples assayed up to 5,950 ounces of gold per ton), the main production adit was collared about 50 feet above Bedrock Creek (Freeman, 1991). By the summer of 1910 the Main adit had been driven 630 feet on the Free Gold claim and a 50 foot shaft with 90 feet of drift was also driven on the main shear zone approximately 800 feet uphill from the Main adit portal (Brooks, 1911). On August 27, 1911, a five stamp Joshua Hendy mill, the first private mill in the Fairbanks Mining District, was put into production on the Free Gold claim. By the end of 1911 there were about 1,200 feet of underground workings at the Cleary Hill mine (Brooks, 1911). By 1912 the Main adit had been driven over 1,050 feet and a second adit, the 215 foot deep Penrose adit, had been driven at an elevation 1 40 feet higher than the Main adit (Cunningham, 1912). The two adits were connected by a 170 foot raise driven 900 feet from the Main adit portal. Over 500 feet of drifting from the Main adit level had developed over 20 stopes. A 30 foot winze was sunk 650 feet from the main adit portal but water hampered its sinking. By the end of 1912, the winze exposed ore 300 feet below the surface outcrops of the lode (Cunningham, 1912). By the end of 1913, Brooks and others (1913) stated that the Main adit of the Cleary Hill mine was 1,280 feet long, the Penrose adit was 280 feet long and the Upper adit was 200 feet long at an elevation 50 feet above the Penrose adit. A total of 1,000 feet of workings were accessed by the main winze with working drifts at the 70- and 112-foot levels. Operating cost allowed only 200 feet of new drifting to be completed in 1915 and the mine closed on September 10, 1915 (Brooks, 1915; Stewart, 1915). The Cleary Hill mine remained closed until 1924 when it was amalgamated with the neighboring Wyoming mine (Stewart, 1923). Efforts to reopen the Cleary Hill mine began in the fall of 1923 and continued through 1929 (Smith, 1924; Moffit and others, 1927; Smith, 1930, B 813). This work included driving a 400 foot adit to access the mine at the 70-foot level of the Main winze. This Lower adit was collared at the level of Bedrock Creek near the mill site (Moffit and others, 1927). In addition, the Upper adit was extended to a total length of 900 feet and 538 feet of crosscuts and a 40 foot raise were extended from this adit (Stewart, 1931). The Penrose adit was extended 45 feet (total length 325 feet) and three crosscuts were driven a total of 595 feet from this adit. An 89 foot raise was driven to connect the Penrose and Upper adits. The Main adit was extended 192 feet (total length of 1,472 feet) and 51 feet of drift was driven on the Powder House shear zone while 154 feet of drift was driven on the Doget shear zone. At a point nea
  • Workings / Exploration = r the mill a shaft was driven 185 feet and a crosscut extended from the shaft bottom for 280 feet. A shaft was also sunk on the ridge an unknown distance above the Upper adit. This shaft, known as the Deep shaft, was 50 feet deep with an 80 foot crosscut at the bottom (Stewart, 1931). . The mine was back in production again in 1929 and rapidly became one of the largest operations in the district (Smith, 1930, B 810; Smith, 1931). In 1930, mining was concentrated in the Penrose adit (Stewart, 1931) and the Cleary Hill mine was again the largest producer in the Fairbanks Mining District (Pilgrim, 1931). The mill operated for a total of 7 months during 1932 and development was concentrated below the Main adit level (Pilgrim, 1933). In 1938 the Cleary Hill mine conducted 250 feet of new drifts and cross-cuts, sank 100 feet of winze and drilled 4,200 feet of AX diamond core. No other work was conducted at the Cleary Hill mine until 1969 when International Minerals and Chemicals excavated two bull dozer trenches on the expected trace of the Cleary Hill shear zone (Pilkington, 1970). This work produced only weakly anomalous gold and silver. The mine waste dumps of the Cleary Hill mine were examined and grab samples were collected by Fairbanks Exploration Inc. during the 1986 field season (Fairbanks Exploration Inc., unpublished report, 1986). In 1988, Tri-Con Mining conducted bulk sampling of the upper and lower Cleary Hill mine dumps to determine if this material could be profitably trucked to the Grant mill for processing.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF LG119
USGS Mineral Resources Data System MRDS A010678
USGS Mineral Resources Data System MRDS D002655
USGS Mineral Resources Data System MRDS A015431
USGS Mineral Resources Data System MRDS A015519

Bibliographic references

  • Deposit

    Brooks, A.H., 1912, The Alaska mining industry in 1911, in Brooks, A.H., and others, Mineral resources of Alaska, 1911: U.S. Geological Survey Bulletin 520, p. 17-44.

  • Deposit

    Cunningham, A., 1912, Engineer describes the Rhoad-Hall Mine: Tanana Magazine, Quartz Edition, p. 39-46.

  • Deposit

    Times Publishing Company, 1912, Tanana Magazine, Quartz Edition: Fairbanks, Alaska 76 p.

  • Deposit

    Smith, P.S., 1913, Lode mining near Fairbanks, in Prindle, L.M., A geologic reconnaissance of the Fairbanks quadrangle, Alaska: U.S. Geological Survey Bulletin 525, p. 153-216.

  • Deposit

    Smith, P.S., 1913, Lode mining near Fairbanks: U.S. Geological Survey Bulletin 542-F, p. 137-202.

  • Deposit

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

  • Deposit

    Eakin, H.M., 1915, Placer mining in Seward Peninsula: U.S. Geological Survey Bulletin 622-I, p. 366-373.

  • Deposit

    Brooks, A.H., 1916, Antimony deposits of Alaska: U.S. Geological Survey Bulletin 649, 67 p.

  • Deposit

    Brooks, A.H., 1916, Antimony deposits of Alaska: U.S. Geological Survey Bulletin 649, 67 p.

  • Deposit

    Smith, P.S., 1917, The mining industry in the territory of Alaska during the calendar year 1915: U.S. Bureau of Mines Bulletin 142, 66 p.

  • Deposit

    Stewart, B.D., 1922, Annual report of the Mine Inspector to the Governor of Alaska: U.S. Bureau of Mines, p. 102.

  • Deposit

    Brooks, A.H., 1923, The Alaska mining industry in 1921: U.S. Geological Survey Bulletin 739, p. 1-50.

  • Deposit

    Smith, P.S., 1926, Mineral industry of Alaska in 1924: U.S. Geological Survey Bulletin 783-A, p. 1-39.

  • Deposit

    Smith, P.S., 1930, Mineral industry of Alaska in 1927: U.S. Geological Survey Bulletin 810-A, p. 1-64.

  • Deposit

    Smith, P.S., 1930, Mineral industry of Alaska in 1928: U.S. Geological Survey Bulletin 813, p. 1-72.

  • Deposit

    Stewart, B.D., 1931, Report on cooperation between Territory of Alaska and the United States in making mining investigations: U.S. Bureau of Mines , p. 94.

  • Deposit

    Pilgrim, E.R., 1932, Progress of lode mining in interior Alaska, 1931: Alaska Territorial Department of Mines Miscellaneous Report 194-4, 9 p.

  • Deposit

    Smith, P.S., 1932, Mineral industry of Alaska in 1929, in Smith, P.S., and others Mineral resources of Alaska, report on progress of investigations in 1929: U.S. Geological Survey Bulletin 824-A, p. 1-81.

  • Deposit

    Hill, J.M., 1933, Lode deposits of the Fairbanks District, Alaska: U.S. Geological Survey Bulletin 849-B, p. 29-163.

  • Deposit

    Pilgrim, E.R., 1933, Progress of lode mining in interior Alaska, 1932: Alaska Territorial Department of Mines Miscellaneous Report 194, 11 p.

  • Deposit

    Smith, P.S., 1933, Mineral industry of Alaska in 1930: U.S. Geological Survey Bulletin 836, p. 1-83.

  • Deposit

    Smith, P.S., 1933, Mineral industry of Alaska in 1931: U.S. Geological Survey Bulletin 844-A, p. 1-81.

  • Deposit

    Smith, P.S., 1934, Mineral industry of Alaska in 1933: U.S. Geological Survey Bulletin 864-A, p. 1-94.

  • Deposit

    Smith, P.S., 1936, Mineral industry in Alaska in 1934: U.S. Geological Survey Bulletin 868-A, p. 1-91.

  • Deposit

    Smith, P.S., 1937, Mineral industry in Alaska in 1935: U.S. Geological Survey Bulletin 880-A, p. 1-95.

  • Deposit

    Smith, P.S., 1938, Mineral industry of Alaska in 1936: U.S. Geological Survey Bulletin 897-A, p. 1-107.

  • Deposit

    Reed, I.M., 1939, Report on lode mining and development in the year 1938 in the Fairbanks mining district, Alaska: Alaska Territorial Department of Mines Internal Report 26 p.

  • Deposit

    Smith, P.S., 1939, Mineral industry of Alaska in 1937: U.S. Geological Survey Bulletin 910-A, p. 1-113.

  • Deposit

    Smith, P.S., 1939, Mineral industry of Alaska in 1938: U.S. Geological Survey Bulletin 917-A, p. 1-113.

  • Deposit

    Joesting, H.R., 1942, Strategic mineral occurences in interior Alaska: Alaska Territorial Department of Mines Pamphlet 1, 46 p.

  • Deposit

    Killeen, P.L., and Mertie, J.B., 1951, Antimony ore in the Fairbanks District, Alaska: U.S. Geological Survey Open-File Report 51-46, 43 p.

  • Deposit

    Wedow, Helmuth, Jr., and White, M.G., 1954, Reconnaissance for radioactive deposits in east-central Alaska, 1949: U.S. Geological Survey Circular 335, 22 p.

  • Deposit

    Byers, F.M., Jr., 1957, Tungsten deposits in the Fairbanks district, Alaska: U.S. Geological Survey Bulletin 1024-I, p. 179-216.

  • Deposit

    Berg, H.C., and Cobb, E.H., 1967, Metalliferous Lode Deposits of Alaska. U.S. Geological Survey Bulletin 1246, 254 p.

  • Deposit

    Chapman, R.M., and Foster, R.L., 1969, Lode mines and prospects in the Fairbanks district, Alaska: U.S. Geological Survey Professional Paper 625-D, 25 p., 1 plate.

  • Deposit

    Pilkington, H.D., 1970, Keystone Mines Inc. exploration program summary: International Minerals & Chemicals Corporation, 61 p. , 1 plate.

  • Deposit

    Cobb, E.H., 1972, Metallic mineral resources map of the Livengood quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map 413, 2 sheets, scale 1:250,000.

  • Deposit

    Cobb, E.H., 1975, Mineral resources of Alaska, in Yount, M.E., ed., U.S. Geological Survey Alaska Program, 1975: U.S. Geological Survey Circular 722, 37 p.

  • Deposit

    Cobb, E.H., 1976, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Circle quadrangle, Alaska: U.S. Geological Survey Open-File Report 76-633, 72 p.

  • Deposit

    Porterfield, J. and Croff, C., 1986, Summary report for the Cleary Project, Fairbanks district, Alaska - 1985: Placid Oil Company Report, 36 p.

  • Deposit

    Metz, P.A., Freeman, C.J., and Calvin, J.S., 1987, Bulk mineable vein-type and disseminated gold mineralization of the Fairbanks Mining District, Alaska: Proceedings, Pacific Rim Congress 87, Australasian Institute of Mining and Metallurgy , p. 333-342.

  • 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

    Freeman, C.J., 1991, 1991 Golden Summit project final report, volume 1: General project summary and exploration summary for the Too Much Gold, Circle Trail, Saddle and Christina prospects: Avalon Development Corp., 164 p. (Report held by Freegold Recovery Inc. USA, Vancouver, British Columbia.)

  • Deposit

    Freeman, C.J., 1992, 1991 Golden Summit project final report, volume 2: Historical summary of lode mines and prospects in the Golden Summit project area, Alaska: Avalon Development Corp., 159 p. (Report held by Freegold Recovery Inc. USA, Vancouver, British Columbia.)

  • Deposit

    Freeman, C.J., Flanigan, B., Currey, J., Wolf, K., and Wietchy D.W., 1998, 1997 and 1998 Final report, Golden Summit project, Fairbanks mining district, Alaska: Avalon Development Corp. Geologic Report GS98-1, 37 p. (Report held by Freegold Recovery Inc. USA, Vancouver, British Columbia.)

  • 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.

Comments on the references

  • Primary Reference = Freeman, 1991

Reporter information

Type Date Name Affiliation Comment
Reporter 04-MAY-99 C.J. Freeman, J.R. Guidetti Schaefer Avalon Development Corporation