Pork Chop

Prospect in Alaska, United States with commodities Gold, Arsenic, Copper, Zinc, Silver, Cadmium, Antimony

Geologic information

Identification information

Deposit ID 10307781
Record type Site
Current site name Pork Chop

Geographic coordinates

Geographic coordinates: -154.59597, 63.51949 (WGS84)
Relative position The Pork Chop prospect is situated near the summit of a southerly spur of the Mystery Mountains about one mile (1.6 km) north of Cottonwood Creek at an elevation of 2,500 feet (762 m) in Section 10, T. 23 S., R. 22 E., of the Kateel River Meridian. Location is accurate to within about 300 feet (91 m).
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Geographic areas

Country State
United States Alaska

Commodities

Commodity Importance
Gold Primary
Arsenic Primary
Copper Primary
Zinc Primary
Silver Secondary
Cadmium Secondary
Antimony Secondary

Materials information

Materials Type of material
Chalcopyrite Ore
Malachite Ore
Pyrite Ore
Gold Ore
Quartz Gangue
Tourmaline Gangue

Alteration

  • (Local) Sericite+quartz+tourmaline+malachite.

Mineral occurrence model information

Model code 85
USGS model code 22c
Deposit model name Polymetallic veins
Mark3 model number 46

Nearby scientific data

(1) -154.59597, 63.51949

Comments on the geologic information

  • Geologic Description = The Pork Chop prospect is one of six mineralized zones that occur in a prominent 7 mile (11 km) long, northeast trending belt that crosses the central part of the Mystery Mountains (DiMarchi and others, 1997). This belt is marked by a central core of copper-gold soil anomalies, and a peripheral zone of lead-zinc soil anomalies (DiMarchi and others, 1997). At Pork Chop, porphyry-like mineralization consist of disseminated chalcopyrite and pyrite in intensive altered tourmaline-quartz veins, vein breccias, and shears, all within several small quartz porphyry bodies that intrude Cretaceous Kuskokwim Group flysch. The Cretaceous flysch is thermally altered to biotite hornfels. Malachite is frequently observed in hairline fractures of intrusions. The strongest tourmaline alteration appears to be near the intersection of northeast trending and northwest trending faults. Most of the hydrothermal alteration is restricted to the quartz porphyry and does not invade the country rock (DiMarchi and others, 1997). The Pork Chop prospect is believed to be Late Cretaceous, based on isotopic age of Mystery Mountains plutonic rocks (Moll and others, 1981). Surface samples analyzed by ASA Inc. run as high as 5,000 ppm copper and 1,000 ppb gold. Clautice and others (1993) report values as high as 141 ppm copper, 788 ppb gold, 1,870 ppm arsenic, 14.0 ppm uranium, 2.00 percent zinc, and 441 ppm cadmium from grab samples at the Pork Chop prospect.
  • Age = the Pork Chop prospect is believed to be Late Cretaceous, based on isotopic age of Mystery Mountains plutonic rocks (Moll and others, 1981).

Economic information

Economic information about the deposit and operations

Development status Prospect

Comments on exploration

  • Status = Active

Mining district

District name McGrath

Comments on the workings information

  • Workings / Exploration = Regional exploration work conducted by WGM Inc. during 1975-to-1978 discovered the Pork Chop, Copenhagen Hill (MD030), and Ursus (MD033) prospects in the Mystery Mountains (Andrews, 1978). Hecla Mining Company explored and sampled the Pork Chop prospect in 1982 (Bell, 1983). From 1988 to 1990, American Copper and Nickel Inc. conducted exploration of the Pork Chop and related prospects in the Mystery Mountains, and flew a detailed airborne geophysical survey of the area. From 1991 to 1997, ASA Inc. continued to explore the Pork Chop and related deposits (DiMarchi and others, 1997). No drilling has taken place at the Pork Chop prospect. Surface samples analyzed by ASA Inc. run as high as 5,000 ppm copper and 1,000 ppb gold. Clautice and others (1993) report values as high as 141 ppm copper, 788 ppb gold, 1,870 ppm arsenic, 14.0 ppm uranium, 2.0 percent zinc, and 441 ppm cadmium from grab samples at the Pork Chop prospect.

Reference information

Links to other databases

Agency Database name Acronym Record ID Notes
USGS Alaska Resource Data File ARDF MD031

Bibliographic references

  • Deposit

    Andrews, Tom, 1978, Summary of Progress, Doyon Project, Mystery Mountains, (Block 10): Anchorage, Alaska, WGM Inc., 24 pages (Held by Doyon Ltd., as proprietary report 78-42).

  • Deposit

    Bell, J.D., 1983, Mystery Mountains Area, Block 10, Doyon Region, Kuskokwim District: Hecla Mining Company Summary Report, 25 pages.

  • Deposit

    Moll, E.J., Silberman, M.L., and Patton, W.W. Jr., 1981, Chemistry, mineralogy, and K-Ar ages of igneous and metamorphic rocks of the Medfra quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-811C, 15 p., 2 sheets, scale 1:250,000.

  • Deposit

    Clautice, K.H., Bowman, N.D., Clough, J.G., Gilbert, W.G., Kline, J.T., Smith, T.E., and Blodgett, R.B., 1993, Land selection Unit 8 (Kantishna River, Ruby, and Medfra quadrangles): References, lead isotope, geochemical and major oxide data: Alaska Division of Geological and Geophysical Surveys, 42 p., 1 sheet, scale 1:250,000.

  • Deposit

    DiMarchi, J.J., and Frantz, P.S., 1997, Annual Report for 1997-Doyon Option Lands, Block 10: ASA Inc.-Montague Gold Joint Venture Report, Volume II: Unpublished report, 189 p. (Report held by Doyon, Limited, Fairbanks, Alaska.)

Comments on the references

  • Primary Reference = DiMarchi and others, 1997

General comments

Subject category Comment text
Deposit Model Name = Porphyry Cu-Au (Cox and Singer, 1986; model no. 22c)
Deposit Other Comments = See Copenhagen Hill (MD030), Mystery Mt. East (MD028), Ursus (MD033), Tarn (MD027), and Frozen Creek (MD032) prospects. The Pork Chop prospect is on land selcted or owned by Doyon Ltd. For additional information, contact Doyon Ltd at 210 1st Ave, Fairbanks, Alaska, 99701.

Reporter information

Type Date Name Affiliation Comment
Reporter 06-JUN-98 Bundtzen, T.K. Pacific Rim Geological Consulting