Three Castle Mountain

Prospect in Alaska, United States with commodities Lead, Zinc, Silver, Uranium

Geologic information

Identification information

Deposit ID 10307416
Record type Site
Current site name Three Castle Mountain

Geographic coordinates

Geographic coordinates: -141.20177, 65.2258 (WGS84)
Relative position The Three Castle Mountain prospects are in two areas, one north of the mountain, and one southwest of it. The Three Castle Mountain North prospects are located in section 29 and 32, T. 5 N., R. 32 E., of the Fairbanks Meridian, and the Three Castle Mountain West prospects are located in sections 8 and 9, T. 4 N., R. 32 E., of the Fairbanks Meridian. Latitude and longitude coordinates are for the Three Castle Mountain North prospects. These prospects are located on Doyon, Limited selected or conveyed land. The locations are accurate.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Lead Primary
Zinc Primary
Silver Secondary
Uranium Secondary

Materials information

Materials Type of material
Pyrite Ore

Alteration

  • (Local) Gossans and local silicification of limestone, along a northeast-trending fault.

Nearby scientific data

(1) -141.20177, 65.2258

Comments on the geologic information

  • Geologic Description = The Three Castle Mountain area is underlain by limestone, shale, and dolomite from the upper Tindir Supergroup (Dover and Miyaoka, 1988). The Three Castle Mountain prospects lie 7 miles southwest of the Nation Gossan prospects (CY021); they exhibit the same type of mineralization and may be part of the same system (Northstar Exploration, Inc., 1999). The Three Castle Mountain prospects consist of northeast-trending gossans that are associated with sulfide mineralization in limestone fault breccias that may be thrust breccias. Lead, zinc, and silver anomalies are common in soil samples, with lead and zinc values ranging from 1,000-10,000 parts per million, and silver ranging from 0.1 to 0.5 ounces per ton. A dolomite sample with secondary silica and traces of pyrite also contained 3.25 parts per million uranium (Northstar Exploration, Inc., 1999). The Three Castle Mountain area has been explored since the mid-1970s by soil and rock sampling.
  • Age = Proterozoic or younger.

Economic information

Economic information about the deposit and operations

Development status Prospect

Comments on exploration

  • Status = Active

Mining district

District name Black

Comments on the workings information

  • Workings / Exploration = The area has been explored since the mid-1970's by soil and rock sampling.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF CY040

Bibliographic references

  • Deposit

    Schmidt, J.M., 1997, Shale-hosted Zn-Pb-Ag and barite deposits of Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska, 1997: Economic Geology Monograph 9, p. 35-65.

  • Deposit

    Northstar Exploration, Inc., 1999, 1998 Annual Report Kandik, Block 7: Fairbanks, Alaska. (Report held by Doyon, Limited, Fairbanks, Alaska.)

Comments on the references

  • Primary Reference = Northstar Exploration, Inc., 1999

General comments

Subject category Comment text
Deposit Model Name = Fault-controlled Zn-Pb?
Deposit Other Comments = These prospects are located on Doyon, Limited selected or conveyed land. For more information, contact Doyon, Limited. This site is within the Yukon-Charley Rivers National Preserve.

Reporter information

Type Date Name Affiliation Comment
Reporter 07-APR-00 Cameron, C.E. Alaska Division of Geological and Geophysical Surveys