Mogul

Prospect in Alaska, United States with commodity Iron
Sections on this page
  1. Identification information
  2. Geographic coordinates
  3. Site location context
  4. Geographic areas
  5. Commodities
  6. Materials information
  7. Alteration
  8. Host and associated rocks
  9. Nearby scientific data
  10. Economic information about the deposit and operations
  11. Mining district
  12. Reserves and resources
  13. Links to other databases
  14. Bibliographic references
  15. General comments
  16. Reporter information

Geologic information

Identification information

Deposit ID 10001945
MRDS ID A012780
Record type Site
Current site name Mogul
Related records 10111625

Geographic coordinates

Geographic coordinates: -165.73469, 64.76122 (WGS84)
Relative position The Mogul prospect is on a rolling hill south of the divide between Trinity Creek to the west and Durrant Creek to the east. It is about 1.5 miles northeast of the Monarch prospect (NM017) and 1.5 miles south-southeast of the Tub Mountain prospect (NM018). The location is the approximate center of a group of limonite occurrences mapped by Herreid (1970). The location is accurate. This is locality 4 of Cobb (1972 [MF 463], 1978 [OFR 78-93]).

Site location context

Political divisions (FIPS codes)

Nome(Census area)

Alaska(state)

United States(country)

North America(continent)

Land(continent)

USGS map quadrangles

Nome D-2(quadrangle 1:63,360 scale)

Solomon NW(quadrangle 1:100,000 scale)

Nome(quadrangle 1:250,000 scale)

Hydrologic units (watersheds)

Nome(hydrologic unit)

Norton Sound(hydrologic accounting unit)

Northwest(hydrologic subregion)

Alaska(hydrologic region)

Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Iron Primary

Materials information

Materials Type of material
Limonite Ore

Alteration

  • (Local) Dolomitization and oxidation.

Host and associated rocks

  • Host or associated Host
    Rock type Metamorphic Rock > Metasedimentary Rock > Marble

Nearby scientific data

(1) -165.73469, 64.76122

Economic information

Comments on the geologic information

  • Geologic Description = The Mogul prospect includes four small concentrations of limonite at or near a contact of marble and schist (Herreid, 1970, figure 1). This prospect is one of several carbonate-hosted, iron-rich deposits in the area (NM014, NM014, NM017, NM018, and NM019). The limonite can be massive to granular, botryoidal, mamillary, or fibrous and commonly occurs in veins along joints and fractures in marble. The iron content ranges to as much as 59 percent in analyzed samples (Eakin, 1915 [B 622-I, p. 361-365]). Hematite, pyrolusite, and calcite are present locally. Shallit (1942; Mulligan and Hess, 1965, table 3) estimated that the Mogul prospect contains 5,000 long tons of rock with 10 to 20 percent iron.? This prospect and other iron deposits of the Sinuk River area occur at or near the base of massive marble whose protolith age is probably lower Paleozoic (Sainsbury, Hummel, and Hudson, 1972; Bundtzen and others, 1994). The deposits are locally controlled by high-angle faults or folds, but they are in general crudely stratabound within the basal massive marble or underlying calc-schist (Mulligan and Hess, 1965; Herreid, 1970). This stratigraphic interval also hosts base metal sulfide-fluorite-barite deposits at the Galena (NM130) and Quarry prospects (NM135).? the origin and age of the iron deposits of the Sinuk River area are uncertain. The deposits may be, in part, gossan developed on oxidized sulfide deposits (Eakin, 1915 [B 622-I, p. 361-365]; Mertie, 1918 {B 662-I, p. 425-449]; Cathcart, 1922; Mulligan and Hess, 1965; Herreid, 1970). Several of the iron deposits, including American (NM014) and Monarch (NM017), are locally highly anomalous in zinc and lead. Arguing against a simple gossan origin is the paucity of diagnostic textures and structures in boxworks that would suggest derivation from specific sulfide minerals. Alternatively, these deposits could be hypogene iron oxide and carbonate deposits probably transitional to lead-zinc-barite deposits such as the Quarry (NM135).? the age of the iron deposits of the Sinuk River area is most likely post-mid-Cretaceous because faults that crosscut mid-Cretaceous metamorphic rocks are an important control on them. A Late Cretaceous age for the iron deposits was suggested by Brobst and others (1971) as this is the age of flourine-rich tin granites of northwestern Seward Peninsula (Hudson and Arth, 1983). The youngest possible age appears to be Early Tertiary, when deep weathering, sandstone-type uranium mineralization, and possibly karst formation occurred to the east in the Solomon quadrangle (Hudson, 1999).
  • Age = Late Cretaceous or Early Tertiary; post mid-Cretaceous metamorphism.

Economic information about the deposit and operations

Development status Prospect
Commodity type Metallic

Comments on exploration

  • Status = Probably inactive

Mining district

District name Nome

Reserves and resources

  • Type In-situ
    Estimate year 1942
    Total resources 2000mt ore
    Remarks Entry carried over from Old MRDS or added later (i.e. it did not originate in ARDF)
    Commodity Subtype Grade units Group Importance Year
    Iron Fe 15 wt-pct Iron Major 1942

Comments on the reserve resource information

  • Reserves = Shallit (1942); Mulligan and Hess, 1965, table 3) estimated that the Mogul prospect contains 5,000 long tons of rock with 10 to 20 percent iron.

Comments on the workings information

  • Workings / Exploration = There may be small prospecting pits at this locality.

Reference information

Bibliographic references

Comments on the references

  • Primary Reference = Herreid, 1970

General comments

Subject category Comment text
Deposit Model Name = Carbonate-hosted, iron oxide deposit.

Reporter information

Type Date Name Affiliation Comment
Reporter 22-OCT-99 Hawley, C.C. Hawley Resource Group
Reporter 22-OCT-99 Travis L. Hudson Hawley Resource Group

Beyond USGS

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

Authoritative Alaska resources

These are landing pages for further research — the state agencies don't currently expose per-mine deep links.