Monarch No. 1 and No. 2

Past Producer in Alaska, United States with commodities Gold, Silver, Lead, REE

Geologic information

Identification information

Deposit ID 10002250
MRDS ID A013152
Record type Site
Current site name Monarch No. 1 and No. 2
Related records 10185696

Geographic coordinates

Geographic coordinates: -136.85045, 58.86639 (WGS84)
Relative position Monarch No. 1 is at an elevation ranging from 1850 to about 2100 feet about 0.2 mile east-northeast of triangulation station End, which has an elevation of 2480 feet. Monarch No. 1 is about one mile above the beach at the mouth of Reid Inlet. The Monarch No. 2 deposit is about 600 feet east of Monarch 1 at an elevation of about 1500 feet. Monarch No. 2's approximate latitude and longitude are, respectively, 58.8688 and 136. 8345. The locations of the prospects are known within 0.1 mile.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary
Silver Secondary
Lead Secondary
REE Secondary

Comments on the commodity information

  • Ore Material = Gold (native)

Materials information

Materials Type of material
Allanite Ore
Arsenopyrite Ore
Chalcopyrite Ore
Galena Ore
Marcasite Ore
Pyrite Ore
Sphalerite Ore
Gold Ore
Calcite Gangue
Quartz Gangue

Alteration

  • (Local) Oligoclase replaces original plagioclase; chlorite, epidote, and calcite are other alteration products (MacKevett and others, 1971, p. 61).

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 Plutonic Rock > Mafic Intrusive Rock > Diorite

Nearby scientific data

(1) -136.85045, 58.86639

Comments on the geologic information

  • Geologic Description = The Monarch veins occur in granodiorite of Cretaceous age (Brew and others, 1978). Rossman (1959, B 1058-B) found two phases of granodiorite within the intrusion, but the differences were too subtle to be mapped.? the Monarch vein-bearing structures belong to a steep fault set of north to north-northwest strike; faults of this are relatively continuous. (Another member of the same set is the Incas vein-fault--MF023). A quartz-vein segment developed in the Monarch No. 1 crops out for 400 feet between 1875 and 2050 feet elevation. It is 1-5 feet thick and was explored for 225 feet in the Monarch No. 1 adit. The vein outcrop locally contained about 1 oz/ton gold (Reed, 1938, p. 63), but assays from underground mostly range from 0.01 to 0.03 ounce per ton gold. There has been little stoping in either Monarch No. 1 or No. 2 underground workings. ? Quartz veins or lenses at the Monarch deposits locally contain pyrite, arsenopyrite, galena and minor free gold. The maximum arsenic detected in 11 vein samples was 7000 ppm (MacKevett and others, 1971, table 11; also Kimball and others, 1978, table C42). Arsenic is much less abundant than in the Le Roy mine (MF022) where the arsenic content is occasionally more than 10 percent. Allanite is apparently a characteristic mineral of the granodiorite near the Monarch.
  • Age = Late Cretaceous or younger.

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 Juneau

Comments on the production information

  • Production Notes = A small production of gold, probably from surface cuts.

Comments on the workings information

  • Workings / Exploration = The Monarch lodes were discovered in 1924 by Joe Ibach, while the National Monument was closed to mining. After the Monument was opened to mining in 1936, Monarch claims were staked by Ibach and Rex Beach. The adit on Monarch No. 1 is 225 eet long, mostly as a drift. Monarch No. 2 was developed with a 140-foot adit with two short drifts. Minor production came from surface cuts and possibly from a small overhand stope at 70 feet in the No. 1 adit. Reed (1938) sampled a surface exposure in the original Monarch five-claim area located by Joseph Ibach and Rex Beach; an exposed vein contained 0.97 ounce per ton gold, 0.50 ounce per ton silver and 1.08 percent zinc. Rossman (1959, p. 50) reported rich veins near the Monarch No. 1; he thought they were too narrow to be significant.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Mineral Resources Data System MRDS A013152
USGS Alaska Resource Data File ARDF MF026

Bibliographic references

  • Deposit

    Rossman, Darwin, 1959, Geology and ore deposits in the Reid Inlet area, Glacier Bay, Alaska: U.S. Geological Survey Bulletin 1058-B, p. 33-58.

  • Deposit

    MacKevett, E.M., Jr., Brew, D.A., Hawley, C.C., Huff, L.C., and Smith, J.G., 1971, Mineral resources of Glacier Bay National Monument, Alaska: U.S. Geological Survey Professional Paper 632, 90 p., 12 plates, scale 1:250,000.

  • Deposit

    Brew, D.A., Johnson, B.R., Grybeck, D., Griscom, A., Barnes, D.F., Kimball, A.L., Still, J.C., and Rataj, J.L., 1978, Mineral resources of the Glacier Bay National Monument Wilderness Study Area, Alaska: U.S. Geological Survey Open-File Report 78-494, 670 p.

  • Deposit

    Kimball, A.L., Still, J.C., and Rataj, J.L., 1978, Mineral resources, in Brew, D. A., and others, Mineral resources of the Glacier Bay National Monument wilderness study area, Alaska: U.S. Geological Survey Open-File Report 78-494, p. C1-C375.

  • Deposit

    Reed, J.C., 1938, Some mineral deposits of Glacier Bay and vicinity, Alaska: Economic Geology, v. 33, p. 52-80.

  • Deposit

    Cobb, E.H., 1972, Metallic mineral resources map of the Mount Fairweather quadrangle, AK: U.S. Geological Survey Miscellaneous Field Study Map MF-436, 1 sheet, scale 1:250,000.

Comments on the references

  • Primary Reference = Rossman, 1959 (B 1058-B); MacKevett and others, 1971

General comments

Subject category Comment text
Deposit Model Name = Low-sulfide gold-quartz vein (Cox and Singer, 1986; model 36a).
Deposit Other Comments = the Monarch structures are weakly mineralized but relatively strong shear zones. Possibly ore might be found on short segments of northeast- striking veins exposed on the Monarch trend to the south. No prospecting is expected in the near future, because the veins are in Glacier Bay National Park and Preserve.

Reporter information

Type Date Name Affiliation Comment
Reporter 08-APR-99 Hawley, C.C. Hawley Resource Group