Neirod - East

Prospect in Alaska, United States with commodities Gold, Arsenic, Copper, Mercury, Lead, Antimony, Zinc

Geologic information

Identification information

Deposit ID 10307773
Record type Site
Current site name Neirod - East

Geographic coordinates

Geographic coordinates: -155.998, 63.53546 (WGS84)
Relative position The Neirod-East prospect lies along a steep westerly slope of the Cripple Creek Mountains at an elevation of 2,350 feet (716 m) in Section 33, T. 22 S., R. 16 E., of the Kateel River Meridian. The reporter investigated the site in 1996.
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary
Arsenic Secondary
Copper Secondary
Mercury Secondary
Lead Secondary
Antimony Secondary
Zinc Secondary

Comments on the commodity information

  • Gangue = Ferricrete breccia

Materials information

Materials Type of material
Arsenopyrite Ore
Boulangerite Ore
Jamesonite Ore
Pyrite Ore
Zinkenite Ore
Tourmaline Gangue
Quartz Gangue

Alteration

  • (Local) Extensive sericitization of plutonic rocks; late tourmaline metasomatism.

Mineral occurrence model information

Model code 78
USGS model code 20c
Deposit model name Porphyry Cu-Au
Mark3 model number 34

Nearby scientific data

(1) -155.998, 63.53546

Comments on the geologic information

  • Geologic Description = An extensive altered zone in border phase plutonic rocks and hornfels extends in a north-south direction for a distance of about 1,968 feet (600 m). The mineralization consists of : (1) ferricrete breccia in the border phase of the Cripple Creek Mountains pluton; (2) stockwork veins in hornfels; and (3) quartz stockwork in fine grained monzonite. The Neirod-East prospect falls within a north 40 degrees east alignment of several metallic lodes--including the Moose Jaw (MD019), Montana Saddle (MD018), and Wyoming Lode (MD016) prospects. Age of mineralization is inferred to be Late Cretaceous based on 71.0 Ma age of adjacent pluton (Bundtzen and others, 1997). . Microprobe analyses of mineralization from the Neirod-East prospect indicates the presence of boulangerite, jamesonite, and zinkenite in addition to the megascopic arsenopyrite observed in hand specimens. Gold is intimately intergrown with jamesonite - an uncommon association (Bart Cannon, written communication, 1998). Five chip channel samples collected along about 1,640 feet (500 m) strike of the zone contained up to 760 ppb gold, 1.00 percent arsenic, 5,360 ppb mercury, and 178 ppm copper (Bundtzen and others, 1997).
  • Age = Late Cretaceous (inferred) based on 71.0 Ma age of adjacent pluton (Bundtzen and others, 1997).

Economic information

Economic information about the deposit and operations

Development status Prospect

Comments on exploration

  • Status = Active

Mining district

District name Innoko

Comments on the workings information

  • Workings / Exploration = Five chip channel samples collected along about 1,640 feet (500 m) strike of the zone contained up to 760 ppb gold, 1.00 percent arsenic, 5,360 ppb mercury, and 178 ppm copper (Bundtzen and others, 1997).

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF MD020

Bibliographic references

  • Deposit

    Patton, W.W., Jr., Moll, E.J., Dutro, J.T., Jr., Silberman, M.L., and Chapman, R.M., 1980, Preliminary geologic map of Medfra quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-811-A, 1 sheet, scale l:250,000.

  • Deposit

    Bundtzen, T.K., Pinney, D.S., and Laird, G.M., 1997, Preliminary geologic map and descriptive data tables from the Ophir C-1 and western Medfra C-6 quadrangles, Alaska: Alaska Division of Geological and Geophysical Surveys Public Data File Report 97-46, 10 p., 1 sheet, scale 1:63,360.

Comments on the references

  • Primary Reference = Bundtzen and others, 1997

General comments

Subject category Comment text
Deposit Model Name = Porphyry Cu-Au (Cox and Singer, 1986; model no. 20c)
Deposit Other Comments = See Montana Saddle prospect (MD018).

Reporter information

Type Date Name Affiliation Comment
Reporter 03-JUN-98 Bundtzen, T.K. Pacific Rim Geological Consulting