Montana Saddle

The Montana Saddle is a gold 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: Montana Saddle

Commodity

Primary: Gold
Secondary: Mercury
Secondary: Arsenic
Secondary: Antimony

Location

State: Alaska
District: Innoko

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: Ankerite alteration near quartz-sulide vein swarms.

Rocks

Not available

Analytical Data

Not available

Materials

Ore: Chalcopyrite
Ore: Arsenopyrite
Gangue: Quartz
Gangue: Feldspar

Comments

Comment (Exploration): Status = Active

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

Comment (Deposit): Other Comments = See Wyoming Lode (MD016), Neirod East (MD020), and Moose Jaw (MD019) prospects.

Comment (Geology): Age = A Late Cretaceous age is inferred based on a 71.0 Ma age for the adjacent Cripple Creek Mountains pluton (Bundtzen and others, 1997).

Comment (Workings): Workings / Exploration = The prospect area has been cut by four trenches of two distinct ages. One trench system is nearly completely overgrown with vegetation, whereas good rock exposures are still preserved in the two younger excavations. Five chip-channel samples of that aggregate about 45 feet (14 m) of vein width yielded an average assay of 465 ppb gold, 968 ppm arsenic, and 1,995 ppb mercury (Bundtzen and others,1997). One sample contained 590 ppm antimony; however, the remaining samples contained only trace amounts. Placer Dome U.S., Inc. and Novagold Inc. sampled and trenched the prospect in 1997 and 1998 respectively.

Comment (Geology): Geologic Description = The Montana Saddle prospect consists of an en echelon series of cox-comb quartz-arsenopyrite-chalcopyrite and quartz-feldspar veinlets ranging from 1 to 5 inches (2.5 to 13 cm) thick in a hornblende granite phase of the Cripple Creek Mountains stock. The vein spacing, which varies from 6 inches to 3 feet (15 cm to 0.9 m), trends in a consistent north 60 degrees east for a traceable strike distance of at least 450 feet (137 m) and for a width of at least 275 feet (84 m), before disappearing under tundra in all directions. . The Montana Saddle prospect is aligned along a north 40 degrees east trending fault mapped by Bundtzen and others (1997), which apparently controls the distribution of other metallic prospects--including the Wyoming (MD016), Neirod-East (MD020), and Moose Jaw (MD019) lodes. The coarse grained, hypidiomorphic, hornblende granite contains about 10 percent olive green hornblende, and contrasts with the biotite pyroxene monzonite phase, which is more typical of the Cripple Creek Mountains stock. Age of mineralization is inferred to be Late Cretaceous based on a 71.0 Ma age for the adjacent Cripple Creek Mountains pluton (Bundtzen and others, 1997). Five chip-channel samples that aggregate about 45 feet (14 m) of vein width yielded an average assay of 465 ppb gold, 968 ppm arsenic, and 1,995 ppb mercury (Bundtzen and others,1997). One sample contained 590 ppm antimony; however, the remaining samples contained only trace amounts of antimony.

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

References

Reference (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.

Reference (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.

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.