Big Gate

Occurrence in Alaska, United States with commodities Zinc, Lead

Geologic information

Identification information

Deposit ID 10307795
Record type Site
Current site name Big Gate

Geographic coordinates

Geographic coordinates: -154.15895, 63.4375 (WGS84)
Relative position The Big Gate zinc occurrence is located at an elevation of approximately 1,700 feet (518 m), east of the North Fork of Soda Creek in Section 1, T. 24 S., R. 24 E., of the Kateel River Meridian. Location is known to within 250 feet (76 m).
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Geographic areas

Country State
United States Alaska


Commodity Importance
Zinc Primary
Lead Secondary

Comments on the commodity information

  • Gangue = Mineralized gossan


  • (Local) Secondary dolomite.

Mineral occurrence model information

Model code 224
USGS model code 32a
BC deposit profile E12
Deposit model name Mississippi Valley, S.E. Missouri Pb-Zn
Mark3 model number 42

Host and associated rocks

  • Host or associated Host
    Stratigraphic age (youngest) Silurian

Nearby scientific data

(1) -154.15895, 63.4375

Comments on the geologic information

  • Geologic Description = The Big Gate iron-rich gossan occurs in the Beaver Dolomite of Andrews and Rishel (1982), the same unit hosting mineralization at the Hillside (MD0049), Beaver (MD048), and Bermuda (MD045) Mississippi Valley Type showings. The gossan occurs in an irregular zone with an approximate surface diameter of 200 feet (61 m). Host units are inferred to be Silurian from fossils (Dutro and Patton, 1982). The age of the mineralization is unknown. Grab samples contained up to 0.1 percent lead and 2.0 percent zinc (Andrews and Rishel, 1982).
  • Age = Host units are inferred to be Silurian from fossils (Dutro and Patton, 1982). The age of the mineralization is unknown.

Economic information

Economic information about the deposit and operations

Development status Occurrence

Comments on exploration

  • Status = Inactive

Mining district

District name McGrath

Comments on the workings information

  • Workings / Exploration = The Big Gate gossan was discovered by WGM Inc. and Patino Ltd. during exploration for base metals in the late 1970s on lands selected by Doyon Ltd. (Andrews and Rishel, 1982). Surface grab samples contained up to 0.1 percent lead and 2.0 percent zinc.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF MD050

Bibliographic references

  • Deposit

    Andrews, Tom, and Rishel, John, 1982, Annual Report for 198, Reef Ridge I-to-XIII Project Areas, Kuskokwim Block, Alaska: Anchorage, Alaska, WGM Inc., Project Report 4, 45 pages, two sheets at 1:63,360 and 1:20,000 scales. (Report held by Doyon, Limited, Fairbanks, Alaska.)

  • Deposit

    Blodgett, R.B., 1982, Stratigraphy of Reef Ridge project area: WGM Inc., Anchorage, Alaska, Reef Ridge Project area, Block 10, Doyon region: 34 pages.

  • Deposit

    Dutro, T.T. Jr., and Patton,W.W. Jr., 1982, New Paleozoic Formations in the northern Kuskokwim Mountains, west-central Alaska: U.S. Geological Survey Bulletin 1529-H, p. H13-H22.

Comments on the references

  • Primary Reference = Andrews and Rishel, 1982

General comments

Subject category Comment text
Deposit Model Name = Southeast Missouri Pb-Zn (Cox and Singer, 1986; model no. 32a) or Mississippi Valley Type.
Deposit Other Comments = See Hillside (MD049), Beaver (MD048), and Bermuda (MD045) Mississippi Valley Type occurrences. The Big Gate occurrence is on land selected or conveyed to Doyon Ltd. For further information, contact Doyon Ltd. at 210 1st Ave., Fairbanks, Alaska, 99701.

Reporter information

Type Date Name Affiliation Comment
Reporter 02-JUN-98 Bundtzen, T.K. Pacific Rim Geological Consulting