Hidden Dike

Prospect in Alaska, United States with commodities Tin, Lead, Silver

Geologic information

Identification information

Deposit ID 10308417
Record type Site
Current site name Hidden Dike

Geographic coordinates

Geographic coordinates: -167.17541, 65.48927 (WGS84)
Relative position The Hidden dike prospect is located on the northwest flank of the ridge between Crystal Creek and the upper part of Cassiterite Creek. Both creeks are east tributaries to Lost River in the York Mountains. The prospect is at about 750 foot elevation and only 0.5 mile upstream from the confluence of Crystal Creek and Lost River. This locality was not identified separately by Cobb and Sainsbury (1972) or Cobb (1975) but the surface trace of the Hidden dike was mapped by Sainsbury (1969, plate 1).
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Geographic areas

Country State
United States Alaska


Commodity Importance
Tin Primary
Lead Secondary
Silver Secondary

Materials information

Materials Type of material
Cassiterite Ore
Galena Ore
Pyrrhotite Gangue
Quartz Gangue
Tourmaline Gangue


  • (Local) Calc-silicate tactite is well developed in carbonate rocks bordering the Hidden dike. The dike itself is variably replaced by tourmaline but large parts are unaltered. The border of the dike appears to have localized irregular solution breccias.

Mineral occurrence model information

Model code 43
USGS model code 14b
Deposit model name Sn skarn
Model code 44
USGS model code 14c
Deposit model name Replacement Sn
Model code 47
USGS model code 15b
Deposit model name Sn veins
Model code 49
USGS model code 15c
Deposit model name Sn greisen

Nearby scientific data

(1) -167.17541, 65.48927

Comments on the geologic information

  • Geologic Description = The Hidden dike is a felsic quartz porphyry that is bordered by layered tactite developed in Ordovician limestone. The contact with tactite is irregular, brecciated, and locally strongly altered. Tourmaline, galena, and pyrrhotite are present in the more strongly altered rocks. Two samples of tourmalized quartz porphyry contained 1.4 and 3.2% tin, 2.9 and 4.45% lead, and 1.1 and 2.9 opt silver. The layered tactite was only weakly anomalous in tin (to 110 ppm) and other elements (Hudson, 1983). . This prospect, the Dalcoath dike prospect 0.75 mile to the east (TE052), the extensive tactite development at lower elevations of the ridge where the Hidden and Dalcoath dikes are located, and an apparently related magnetic anomaly (McDermott, 1983) suggests the possibility of a tin mineralizing system at depth in this general area (Hudson, 1983). The surface dikes are not believed to be directly responsible for the nearby tactite development.
  • Age = the age of the mineralization is assumed to be related to the development of tin systems in the Lost River area and therefore Late Cretaceous, the age of the tin-mineralizing granites there (Hudson and Arth, 1983).

Economic information

Economic information about the deposit and operations

Development status Prospect

Comments on exploration

  • Status = Inactive

Mining district

District name Port Clarence

Comments on the reserve resource information

  • Reserves = Not defined

Comments on the workings information

  • Workings / Exploration = Only limited surface observations and sampling have been completed here.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF TE053

Bibliographic references

  • Deposit

    Cobb, E.H., and Sainsbury, C.L., 1972, Metallic mineral resource map of the Teller quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-426, 1 sheet, scale 1:250,000.

  • Deposit

    Sainsbury, C.L., 1972, Geologic map of the Teller quadrangle, Seward Peninsula, Alaska: U.S. Geological Survey Map I-685, 4 p., 1 sheet, scale 1:250,000.

  • Deposit

    McDermott, M.M., 1983, Investigation of the magnetic contact aureoles of the Khotol and Black Mountain granites, Alaska: Anchorage, Alaska, Anaconda Minerals Company internal report (Report held by Cook Inlet Region, Inc., Anchorage, Alaska).

  • Deposit

    Hudson, T.L., and Arth, J. G., 1983, Tin-granites of Seward Peninsula, Alaska: Geological Society of America Bulletin, v. 94, p. 768-790.

  • Deposit

    Sainsbury, C.L., 1969, Geology and ore deposits of the central York Mountains, western Seward Peninsula, Alaska: U.S. Geological Survey Bulletin 1287, 101 p.

  • Deposit

    Cobb, E.H., 1975, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Teller quadrangle, Alaska: U.S. Geological Survey Open-File Report 75-587, 130 p.

  • Deposit

    Hudson, T.L., 1983, Interim report on the Lost River district, Seward Peninsula, Alaska: Anchorage, Alaska, Anaconda Minerals Company internal report (Report held by Cook Inlet Region, Inc., Anchorage, Alaska).

Comments on the references

  • Primary Reference = Hudson, 1983

General comments

Subject category Comment text
Deposit Model Name = Altered quartz porphyry dike in tactite. Deposit analog is not clear; possibly tin vein model (15b), or at depth, tin skarn, replacement, or greisen models(14b, 14c, and 15c) after Cox and Singer (1986).
Deposit Model Number = 14b, 14c, 15b, 15c

Reporter information

Type Date Name Affiliation Comment
Reporter 10-MAY-98 Travis L. Hudson Applied Geology