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Unnamed (north of upper Antler Creek)

Prospect in Alaska, United States with commodities Copper, Molybdenum, Gold, Zinc, Silver
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Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Public Land Survey System information
  6. Commodities
  7. Materials information
  8. Mineral occurrence model information
  9. Host and associated rocks
  10. Nearby scientific data
  11. Ore body information
  12. Economic information about the deposit and operations
  13. Mining district
  14. Mineral rights holdings
  15. Land status
  16. Ownership information
  17. Reserves and resources
  18. Workings at the site
  19. Links to other databases
  20. Bibliographic references
  21. General comments
  22. Reporter information

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.

Site location context

Political divisions (FIPS codes)

Valdez-Cordova(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Nabesna A-4(quadrangle 1:63,360 scale)

Nabesna SW(quadrangle 1:100,000 scale)

Nabesna C(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Alaska(hydrologic region)

Federal lands

Wrangell-St. Elias National Preserve(National Preserve)

National Preserve NPS(Type of land area)

NPS(Federal land areas administered by NPS)

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 Critical 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
ListMap

Economic information

Ore body information

  • Thickness 335M
    Length 1220M
    Width 610M
    Area 20HA
    Depth to top 0M
    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 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 290300000mt ore
    Total resources 290300000mt ore
    Commodity Subtype Grade units Group Importance Year
    Molybdenum Mo 0.018 wt-pct Molybdenum Major 1979
    Copper Cu 0.35 wt-pct Copper Major 1979
  • Type In-situ
    Estimate year 1979
    Demonstrated 187000000mt ore
    Total resources 187000000mt ore
    Commodity Subtype Grade units Group Importance Year
    Molybdenum Mo 0.015 wt-pct Molybdenum Major 1979
    Copper Cu 0.35 wt-pct Copper Major 1979
  • Type In-situ
    Estimate year 1991
    Demonstrated 290300000mt ore
    Total resources 290300000mt ore
    Commodity Subtype Grade units Group Importance Year
    Molybdenum Mo 0.018 wt-pct Molybdenum Major 1991
    Gold Au 0.39 g/mt Gold Trace 1991
    Copper Cu 0.35 wt-pct Copper Major 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

Bibliographic references

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

Beyond USGS

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

Maps centered on this site

Authoritative Alaska resources

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