Mystery Mountains East

The Mystery Mountains East is a copper mine located in Alaska.

About the MRDS Data:

All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.

Mine Info

Satelite View

MRDS mine locations are often very general, and in some cases are incorrect. Some mine remains have been covered or removed by modern industrial activity or by development of things like housing. The satellite view offers a quick glimpse as to whether the MRDS location corresponds to visible mine remains.

Site Name

Primary: Mystery Mountains East

Commodity

Primary: Copper
Secondary: Silver
Secondary: Antimony
Secondary: Arsenic

Location

State: Alaska
District: McGrath

Land Status

Not available

Holdings

Not available

Workings

Not available

Ownership

Not available

Production

Not available

Deposit

Record Type: Site
Operation Category: Prospect
Operation Type: Unknown
Years of Production:
Organization:
Significant:

Physiography

Not available

Mineral Deposit Model

Model Name: Porphyry Cu-Au

Orebody

Not available

Structure

Not available

Alterations

Alteration Type: L
Alteration Text: Biotite, tourmaline, and quartz.

Rocks

Not available

Analytical Data

Not available

Materials

Ore: Stibnite
Ore: Pyrite
Ore: Chalcopyrite
Ore: Arsenopyrite
Gangue: Tourmaline
Gangue: Quartz

Comments

Comment (Exploration): Status = Inactive

Comment (Geology): Age = the Mystery Mountain East prospect is inferred to be Late Cretaceous, based on isotopic ages from Mystery Mountains plutonic rocks (Moll and others, 1981).

Comment (Reference): Primary Reference = DiMarchi and others, 1997

Comment (Workings): Workings / Exploration = WGM Inc. located a number of porphyry-like prospects in the Mystery Mountains during the late 1970s (Andrews, 1978). From 1988 to 1990, ACNC conducted detailed exploration work, which included an airborne geophysical survey. ASA Inc. continued work from 1991 to 1997. Surface grab samples from the Mystery Mountains East prospect ran as high as 830 ppm arsenic, 203 ppm copper, 2.0 ppm silver, but contained no gold (DiMarchi and others, 1997).

Comment (Deposit): Model Name = Porphyry Cu-Au (Cox and Singer, 1986; model no. 20c)

Comment (Deposit): Other Comments = See Copenhagen Hill (MD030), Frozen Creek (MD032), Tarn (MD027), and Pork Chop (MD031) prospects.

Comment (Geology): Geologic Description = The Mystery Mountains East prospect is one of a number of porphyry-like copper-gold prospects that occur along a seven mile (11 km) long, northeast trending belt through the central Mystery Mountains. Mineralization consists of tourmaline quartz veins, breccia veins, and fractures associated with small monzonite and quartz porphyry bodies hosted in biotite hornfels (DiMarchi and others, 1997). Sulfides include arsenopyrite, chalcopyrite, pyrite, and traces of stibnite, within a 600 feet by 600 feet (183 m by 183 m) area. The Mystery Mountain East prospect is inferred to be Late Cretaceous, based on isotopic ages from Mystery Mountains plutonic rocks (Moll and others, 1981). Surface grab samples from the Mystery Mountains East prospect ran as high as 830 ppm arsenic, 203 ppm copper, 2.0 ppm silver, but contained no gold (DiMarchi and others, 1997).

References

Reference (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.)

Reference (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.

Reference (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).

The Top Ten Gold Producing States

These ten states contributed the most to the gold production that built the West from 1848 through the 1930s. The Top Ten Gold Producing States.