Unnamed (north of upper Antler Creek)

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

Geologic information

Identification information

Deposit ID 10258737
MRDS ID A011395
MAS/MILS ID 0020780015
Record type Site
Current site name Unnamed (north of upper Antler Creek)
Alternate or previous names Orange Hill, Alaska Nabesna Corporation, Sargent Mine, Camp Bird, Lemon, Nebesna, North Star Group, Glacier Claim, California Group, Copper King, Unnamed

Geographic coordinates

Point of reference Ore Body
Geographic coordinates: -142.84744, 62.20369 (WGS84)
Elevation 884
Location accuracy 100(meters)
Relative position This prospect is on the northeast flank of Orange Hill, 10 miles southeast of Nabesna Mine, near the head of the Nabesna River in Upper Copper River region. It is in an unnamed drainage (locally named California Gulch) that flows north-northwest to near the Orange Hill airstrip, which is 0.5 mile northwest of the prospect.
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Geographic areas

Country State
United States Alaska

Public Land Survey System information

Meridian Township Range Section Fraction State
Copper River 005 N 014 E 20 ne1/4 Alaska

Commodities

Commodity Importance
Copper Primary
Molybdenum Primary
Gold Secondary
Zinc Tertiary
Silver Secondary

Materials information

Materials Type of material
Bornite Ore
Chalcopyrite Ore
Molybdenite Ore
Pyrite Ore
Sphalerite Ore
Tetrahedrite Ore
Anhydrite Gangue
Calcite Gangue
Gypsum Gangue
Quartz Gangue
Biotite Unknown
Chlorite Unknown
Epidote Unknown
Feldspar Unknown
Hornblende Unknown
Kaolin Unknown
Limonite Unknown
Magnetite Unknown
Sericite Unknown

Mineral occurrence model information

Model code 79
USGS model code 21a
Deposit model name Porphyry Cu-Mo
Mark3 model number 2

Host and associated rocks

  • Host or associated Host
    Rock type Plutonic Rock > Mafic Intrusive Rock > Diorite
    Rock unit name Nabesna batholith
  • Host or associated Associated
    Rock type Volcanic Rock (Aphanitic) > Felsic Volcanic Rock > Dacite

Nearby scientific data

Ore Body (1) -142.84744, 62.20369

Ore body information

  • Thickness 335M
    Depth to top 0M
    Width 610M
    Length 1220M
    Area 20HA
    Field Value
    Type of Orebody #1 STOCKWORK
    Shape of Orebody #1 MASSIVE
    Type of Orebody #2 DISSEMINATED
    Primary mode of Origin HYDROTHERMAL
    Secondary mode of Origin HYDROTHERMAL
    Primary Ore Control IGNEOUS
    Degree of Wallrock Alter. UNKNOWN
    Type of Wallrock Alter. #1 UNKNOWN
    Minimum Depth to Top 0
    Avg. Thick. Unconsol. Mat. 0
    Min. Thick. Unconsol. Mat. 0
    Total Surface Area (HA) 20
    Date of Last Modification 880212

Comments on the geologic information

  • The Orange Hill porphyry copper prospect was first discovered and staked as early as 1902 for its possible gold content (Mendenhall and Schrader, 1903). By 1940, 18 mining claims had been patented, including contiguous claims that extend southeast across contact metamorphic deposits (Moffit, 1943, 1954; also see NB044). Over the years, the prospect has been extensively explored by open cuts, short adits, and much diamond drilling. Pyrite, chalcopyrite, and molybdenite occur in quartz veinlets and as disseminations in quartz diorite and granodiorite intruded by quartz plagioclase porphyry (Richter and others, 1975). Hydrothermal alteration is well developed in the Orange Hill deposit (Linn, 1973; Hollister and others, 1975; Richter and others, 1975). A central 400 by 2,000 meter altered zone contains abundant biotite, quartz veinlets, minor K-feldspar, chlorite, and sericite. It is cut by late anhydrite veins. An outer 1,000 by 3,000 meter altered zone contains chlorite, minor sericite, and anhydrite. The deposit has been extensively oxidized and iron-oxide staining is abundant. Surface copper grades are less than 0.4 percent and average about 0.25 percent. Surface molybdenum grades are as high as 0.8 percent but average about 0.01 percent. The average grade of the non-oxidized mineralization is estimated to be 0.35 percent copper and 0.02 percent molybdenum (Richter and others, 1975). Gold values range up to 0.04 ounce per ton and probably average about 0.005 ounce per ton (Van Alstine and Black, 1944; Richter and others, 1975 ). The average silver grade is estimated to be 0.01 ounce per ton (Van Alstine and Black, 1944). Three estimates of the tonnage and grade of the Orange Hill deposit are: 1) 210 million tons grading 0.04 per cent copper and 0.02 percent molybdenum (Van Alstine and Black, 1944); 2) 86 million tons grading 0.3 or more percent copper and 0.015 percent molybdenite (Linn, 1973); and 3) 320 million tons grading 0.35 percent copper and 0.02 percent molybdenum (Richter and others, 1975). Richter and others (1975) estimate the deposit contains 1.6 million ounces of gold and 3.2 million ounces of silver. The Orange Hill deposit is within quartz diorite and granodiorite of the southwestern border zone of the mid-Cretaceous Nabesna pluton. The granitic rocks in turn are intruded by quartz-plagioclase porphyry that is also inferred to be Cretaceous in age (Richter, 1973). Many varieties of hornblende-plagioclase porphyry form irregular intrusive bodies in the Nabesna pluton and other regional bedrock units in the area; these are considered to be Tertiary in age (Richter, 1973). K/Ar ages for the Nabesna pluton range from 105 +/- 4.0 to 114 +/- 3.4 Ma (Richter and others, 1975; Richter, Lanphere, and Matson, 1975). Country rocks to the Nabesna pluton at Orange Hill include upper Paleozoic metavolcanic rocks, Permian limestone, Permian or Triassic argillite, and Triassic, Nikolai Greenstone (Richter, 1973).
  • Alteration = A central 400 by 2,000 meter altered zone contains abundant biotite, quartz veinlets, minor K-feldspar, chlorite, and sericite. It is cut by late anhydrite veins. An outer 1,000 by 3,000 meter altered zone contains chlorite, minor sericite, and anhydrite. The deposit has been extensively oxidized and iron-oxide staining is abundant.

Economic information

Economic information about the deposit and operations

Operation type Surface
Development status Prospect
Commodity type Metallic
Deposit size Large
Significant Yes
Discovery year 1898
Mining method Open Pit
Milling method Flotation

Comments on exploration

  • Status = Inactive

Mining district

District name Chisana

Mineral rights holdings

Type of mineral rights Located Claim
Type of mineral rights Patented

Land status

Ownership category Federal

Ownership information

  • Type Owner
    Owner RTZ Corp.
    Interest 100
    Year 1990
    First year 1990

Comments on the ownership information

  • OWNERSHIP ADDRESS A.J.V. CORPORATION 10018 NORTH HUNTINGTON ROAD SPOKANE, WASHINGTON 99218 TEL: (509)466-8636

Reserves and resources

  • Type In-situ
    Estimate year 1979
    Demonstrated 290,300,000mt ore
    Total resources 290,300,000mt ore
    Commodity Subtype Grade units Group Importance Year
    Copper Cu 0.35 wt-pct Copper Major 1979
    Molybdenum Mo 0.018 wt-pct Molybdenum Major 1979
  • Type In-situ
    Estimate year 1979
    Demonstrated 187,000,000mt ore
    Total resources 187,000,000mt ore
    Commodity Subtype Grade units Group Importance Year
    Copper Cu 0.35 wt-pct Copper Major 1979
    Molybdenum Mo 0.015 wt-pct Molybdenum Major 1979
  • Type In-situ
    Estimate year 1991
    Demonstrated 290,300,000mt ore
    Total resources 290,300,000mt ore
    Commodity Subtype Grade units Group Importance Year
    Copper Cu 0.35 wt-pct Copper Major 1991
    Molybdenum Mo 0.018 wt-pct Molybdenum Major 1991
    Gold Au 0.39 g/mt Gold Trace 1991

Comments on the reserve resource information

  • E/MJ 5/79, P83. , U.S.G.S. PUB. (MAP I-655)
  • THIS DEPOSIT IS COMBINED WITH THE BOND CREEK DEPOSIT FOR THE COPPER SUPPLY ANALYSIS STUDY. NEW PARENT COMPANY IS RTZ CORP. AS OF 6/89. ORANGE HILL: 250 MIL. MT @ .35% CU, .015% MO - DEMO (MINEABLE) 320 MIL. MT @ .35% CU, .012% MO - IDENTIFIED DEMONSTRATED IN-SITU RESOURCE AS OF 12/31/78 DEMONSTRATED MINEABLE RESERVE ESTIMATED AT: 187,000,000 MT @ 0.35% CU, 0.015% MO
  • The average grade of the unoxidized mineralization is estimated to be 0.35 percent copper and 0.02 percent molybdenum (Richter and others, 1975). Gold values range up to 0.04 ounce per ton and probably average about 0.005 ounce per ton (Van Alstine and Black, 1944; Richter and others, 1975). The average silver grade is estimated to be 0.01 ounce per ton (Van Alstine and Black, 1944). Three estimates of the tonnage and grade of the Orange Hill deposit are: 1) 210 million tons grading 0.04 per cent copper and 0.02 percent molybdenum (Van Alstine and Black, 1944); 2) 86 million tons grading 0.3 or more percent copper and 0.015 percent molybdenite (Linn, 1973); and 3) 320 million tons grading 0.35 percent copper and 0.02 percent molybdenum (Richter and others, 1975). Richter and others (1975) estimate the deposit contains 1.6 million ounces of gold and 3.2 million ounces of silver.

Workings at the site

  • Type of workings Surface
    Area 75HA
    Field Value
    MAS Development Schedule # 1
    Mining Record # 1
    Status of Mining Method PROPOSED
    Mining Method BENCH (BERM)
    Avg. Bench Height (meters) 15
    Max. Pit Slope (degrees) 45
    Capacity 20000
    Capacity Units MT ORE/DAY
    Preprod. Stripping Vol. 0
    Unit Production Cost 5.03
    Units of Production $/MT ORE
    Operating Days per Year 300
    Operating Shifts per Day 2
    Year of Information 1984

Comments on the workings information

  • The Orange Hill porphyry copper prospect was first discovered and staked as early as 1902 for its possible gold content (Mendenhall and Schrader, 1903). By 1940, 18 mining claims, a millsite, and a homestead had been patented. The mining claims include several contiguous claims that extend southeast across contact metamorphic deposits (Moffit, 1943; 1954; also see NB044). Over the years, the prospect has been extensively explored by open cuts, shafts, short adits, and much diamond drilling. The underground workings total only 250 to 300 feet and most were reported be caved by 1944 (Van Alstine and Black, 1944).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
U.S. Bureau of Mines Minerals Availability System MAS 0020780015
USGS Mineral Resources Data System MRDS A011395 MAS references MRDS
USGS Alaska Resource Data File ARDF NB030
USGS Mineral Resources Data System MRDS 10000755 Orange Hill merged with this record (dep_id 10258737).
USGS Mineral Resources Data System MRDS 10008294 Orange Hill merged with this record (dep_id 10258737).

Bibliographic references

  • Deposit

    Hollister, V.F., Anzalone, S.A., and Richter, D.H., 1975, Porphyry copper belts of southern Alaska and contiguous Yukon Territory: CIM Bulletin (Canadian Mining and Metallurgical Bulletin), V. 68, NO. 756, P. 104-112.

  • Geology

    Linn, G.W., 1973, Geology of Orange Hill, Alaska: Berkeley, University of California, M.A. thesis, 119 p.

  • Ownership

    ALASKA KARDEX 078-014

  • Reference

    Cobb, E.H., and Richter, D.H., 1980, Summaries of data on and list of references to metallic and selected nonmetallic mineral deposits in the Nabesna quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-927, 117 p.

  • Deposit

    Pilgrim, E.R., 1931, Alaska Nabesna Orange Hill copper claims, in Stewart, B.D., Report on cooperation between the Territory of Alaska and the United States in making mining investigations and in inspection of mines for the biennium ending March 31, 1931, p. 69-74.

  • Geology

    Richter, D.H., Lanphere, M.A., and Matson, N.A., Jr., 1975, Granite plutonism and metamorphism, eeastern Alaska Range, Alaska: Geological Society of American Bulletin, v. 86, p. 819-820.

  • Ownership

    ALASKA KARDEX 078-061

  • Reserve-Resource

    Berg, H.C., Eberlein, G.D., and MacKevett, Jr., E.M., 1964, Metallic mineral resources, in Mineral and water resources of Alaska, Report prepared by the United States Geological Survey in cooperation with State of Alaska Department of Natural Resources at the request of Senator Ernest Gruening of Alaska of the Committee on Interior and Insular Affairs United States Senate, U.S. Government Printing Office, Washington, D.C., p. 95-125.

  • 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.

  • Reserve-Resource

    Engineering and Mining Journal 7905

  • Deposit

    U.S. Geological Survey, 1977 (1978), Geological Survey research, 1977: U.S. Geological Survey Professional Paper 1050, 411 p.

  • Deposit

    Mendenhall, W.C., and Schrader, F.C., 1903, The mineral resources of the Mount Wrangell district, Alaska: U.S. Geological Survey Professional Paper 15, 71 p.

  • Deposit

    Moffit, F.H., Knopf, Adolph, and Capps, S.R., 1910, Mineral resources of the Nabesna-White River district, Alaska, with a section on Quaternary deposits and glaciation in the Nabesna-White River district by S.R. Capps: U.S. Geological Survey Bulletin 417, 64 p.

  • Deposit

    Capps, S.R., 1915, Mineral resources of the Chisana-White River district, U.S. Geological Survey Bulletin 622-K, p. 189-228, in Brooks, A.H., 1915, Mineral resources of Alaska; report on progress of investigations in 1914: U.S. Geological Survey Bulletin 622, 380 p.

  • Deposit

    Smith, P.S., 1929, Mineral industry of Alaska in 1926: U.S. Geological Survey Bulletin 797-A, p. 1-50, in U.S. Geological Survey Staff, 1929, Mineral resources of Alaska, report on progress of investigations in 1926: U.S. Geological Survey Bulletin 797, 227 p.

  • Deposit

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

  • 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

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

  • Deposit

    Moffit, F.H., 1937, Recent mineral developments in the Copper River region: U.S. Geological Survey Bulletin 880-B, p. 97-109.

  • Deposit

    Smith, P.S., 1942, Occurrences of molybdenum in Alaska: U.S. Geological Survey Bulletin 926-C, p. 161-210.

  • Deposit

    Moffit, F.H., 1943, Geology of the Nutzotin Mountains, Alaska, with a section on The igneous rocks, by R.C. Wayland, and Gold deposits near Nabesna, by R.C. Wayland: U.S. Geological Survey Bulletin 933-B, p. 103-199.

  • Deposit

    Van Alstine, R.E., and Black, R.F., 1944, Mineral deposits at Orange Hill, Alaska: U.S. Geological Survey Open-File Report 76, 16 p., 1 sheet.

  • Deposit

    Wedow, Helmuth, Jr., White, M.G. and Moxham, R.M., 1952, Interim report on an appraisal of the uranium possibilities of Alaska: U.S. Geological Survey Open-File Report 51, 123 p.

  • Deposit

    Wedow, Helmuth, Jr., 1953, Preliminary summary of reconnaissance for uranium and thorium in Alaska, 1952: U.S. Geological Survey Circular 248, 15 p.

  • Deposit

    Twenhofel, W.S., 1953, Potential Alaskan mineral resources for proposed electrochemical and electrometallurgical industries in the upper Lynn Canal area, Alaska: U.S. Geological Survey Circular 252, 14 p.

  • Deposit

    Moffit, F.H., 1954, Geology of the eastern part of the Alaska Range and adjacent area: U.S. Geological Survey Bulletin 989-D, p. 65-218.

  • Deposit

    Nelson, A.E., West, W.S., and Matsko, J.J., (1952) 1954, Reconnaissance for radioactive deposits in eastern Alaska: U.S. Geological Survey Circular 348, 21 p.

  • Deposit

    McInnes, Wilmer, 1957, Molybdenum, a materials survey, with a chapter on geology and resources by S.C. Creasy: U.S. Bureau of Mines Information Circular 7784, 77 p.

  • Deposit

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

  • Deposit

    Richter, D.H., 1967, Geology of the upper Slana-Mentasta Pass area, southcentral Alaska: Alaska Division of Mines and Minerals Geologic Report 30, 30 p., 2 sheets, scale 1:63,360.

  • Deposit

    Richter, D.H., and Matson, N.A., Jr., 1970, Geochemical data from the Nabesna A-4 quadrangle, Alaska: U.S. Geological Survey Open File Report: Technical Data Unit classification number 398, 8 p., 1 sheet. Superseded by: Richter, D.H., and Matson, N.A., Jr., 1970, Geochemical data from the Nabesna A-4 quadrangle, Alaska: U.S. Geological Survey Open-File Report 70-276, 8 p., 1 sheet, scale 1:63,360.

  • Deposit

    Richter, D.H., Singer, D.A., and Cox, D.P., 1975, Mineral resources map of the Nabesna quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-655-K, 1 sheet, scale 1:250,000.

  • Deposit

    Richter, D.H., and Matson, N.A., 1972, Metallic mineral resources map of the Nabesna quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-422, scale 1:250,000.

  • Deposit

    Richter, D.H., 1972, Reconnaissance geologic map of the Nabesna A-4 quadrangle, Alaska: U.S. Geological Survey Open File Report: Technical Data Unit classification number 509, 1 sheet. Superseded by: Richter, D.H., 1972, Reconnaissance geologic map of the Nabesna A-4 quadrangle, Alaska: U.S. Geological Survey Open-File Report 72-313, 1 sheet.

  • Deposit

    Richter, D.H., 1973, Reconnaissance geological map of the Nabesna A-4 quadrangle, Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map I-789, Scale 1:63,360.

  • Deposit

    Richter, D.H., Albert, N.R.D., Barnes, D.F., Griscom, A., Marsh, S.P., and Singer, D.A., 1976, The Alaskan mineral resource assessment program ?background information to accompany folio of geologic and mineral resource maps of the Nabesna quadrangle, Alaska: U.S. Geological Survey Circular 718, 27p.

  • Deposit

    CIM BULL 7504 Canadian Institute of Mining, Metallurgy, and Petroleum?

  • Deposit

    Richter, D.H., 1976, Geologic map of the Nabesna quadrangle, Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map I-932, 1 sheet, scale 1:250,000.

  • Deposit

    MacKevett, E.M., Jr., and Holloway, C.D., 1977, Map showing metalliferous and selected non-metalliferous mineral deposits in the eastern part of southern Alaska: U.S. Geological Survey Open-File Report 77-169-A, 99 p., 1 sheet, scale 1:1,000,000.

  • Deposit

    Engineering and Mining Journal 7905 No. 145

  • Deposit

    Bundtzen, T.K., Eakins, G.R., and Conwell, C.N., 1983, Alaska mineral resources 1981-82: Alaska Division of Geological and Geophysical Surveys, Annual Report 1981-82, 153 p., scale 1:2,500,000, 4 sheets.

  • Deposit

    MTA 82 No. E-49

  • Deposit

    SR38 No. 73

  • Deposit

    Berg, H.C., Eberlein, G.D., and MacKevett, Jr., E.M., 1964, Metallic mineral resources, in Mineral and water resources of Alaska, Report prepared by the United States Geological Survey in cooperation with State of Alaska Department of Natural Resources at the request of Senator Ernest Gruening of Alaska of the Committee on Interior and Insular Affairs United States Senate, U.S. Government Printing Office, Washington, D.C., p. 95-125.

  • Deposit

    Herreid, G., 1961, Geology and ore deposits of Alaska, State Division of Mines and Minerals, (Reprinted from Mining Enpineering Magazine).

  • Deposit

    Direxp 1940

  • Deposit

    Mendenhall, W.C., and Schrader, F.C., 1903, The mineral resources of the Mount Wrangell district, Alaska: U.S. Geological Survey Professional Paper 15, 71 p.

  • Deposit

    Richter, D.H., and Matson, N.A., 1970, Geochemical data from the Nabesna A-4 quadrangle, Alaska: U.S. Geological Survey Open-File Report 70-276, 14 P., 1 sheet, scale 1:63,360.

Comments on the references

  • MINING WORLD, 1971, NO.4, P. 4-8

General comments

Subject category Comment text
Age Mid-Cretaceous. The intrusive host rocks to the Orange Hill deposit are considered to be part of the Nabesna pluton. K/Ar ages for the Nabesna pluton range from 105 +/- 4.0 to 114 +/- 3.4 Ma (Richter and others, 1975; Richter, Lanphere, and Matson, 1975). Many varieties of hornblende-plagioclase porphyry form irregular intrusive bodies into the Nabesna pluton and other regional bedrock units in the area; these are considered to be Tertiary in age (Richter, 1973).
Deposit USGS CRIB W016505 PROPOSED BENEFICIATION WITH BOND CREEK DEPOSIT 0020780016 FEED RATE: BOND CREEK=56%, ORANGE HILL=44% LANDS WITHDRAWN AS WRANGELL MT. NATIONAL PRESERVE PATENTED CLAIMS UNDER U.S. PAT. NO. 914107, DATED 1923 PATENTED CLAIMS UNDER M.S. 1414-A ROAD PRESENTLY EXISTS TO NABESNA- 14 MILES FROM ORANGE HILL ALL ELECTRICAL POWER MUST BE GENERATED ON SITE WASTE VOLUME ESTIMATED AT 12.1 CU FT/SHORT TON POWDER FACTOR CONSIDERED AT .25 LB/S.T. FOR ANFO EXPLOSIVE

Reporter information

Type Date Name Affiliation Comment
Reporter 01-JUL-74 King, Robert U. U.S. Geological Survey
Reporter 01-APR-85 Leonard, Kenneth R. (Elliott, R.L.) U.S. Geological Survey
Updater 29-MAY-92 Beougher, Dee (Spanski, Gregory T.) U.S. Geological Survey
Editor 27-APR-95 Mosier, Dan U.S. Geological Survey
Reporter 17-OCT-96 WSR U.S. Bureau of Mines
Updater 01-JAN-97 Leonard, Kenneth R. (Elliott, R.L.) U.S. Geological Survey
Editor 06-MAR-98 Mason, George U.S. Geological Survey
Reporter 11-NOV-02 Hudson, Travis Applied Geology