Montgomery Prospect

The Montgomery Prospect is a copper and nickel mine located in Boundary county, Idaho at an elevation of 3,100 feet.

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

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Site Name

Primary: Montgomery Prospect

Commodity

Primary: Copper
Primary: Nickel
Tertiary: Zinc
Tertiary: Cobalt
Tertiary: Gold
Tertiary: Lead

Location

State: Idaho
County: Boundary
District: Moyie-Yaak District

Land Status

Land ownership: National Forest
Note: the land ownership field only identifies whether the area the mine is in is generally on public lands like Forest Service or BLM land, or if it is in an area that is generally private property. It does not definitively identify property status, nor does it indicate claim status or whether an area is open to prospecting. Always respect private property.
Administrative Organization: Kaniksu National Forest

Holdings

Type: Located Claim

Workings

Type: Underground

Ownership

Owner Name: M. N. Seeley
Home Office: Wyoming
Info Year: 1953

Owner Name: Montgomery Mines, Inc.
Home Office: Idaho
Info Year: 1953

Production

Not available

Deposit

Record Type: Site
Operation Category: Prospect
Operation Type: Underground
Discovery Method: Unknown
Years of Production:
Organization:
Significant: N
Deposit Size: S

Physiography

General Physiographic Area: Rocky Mountain System
Physiographic Province: Northern Rocky Mountains
Physiographic Detail: Purcell Range

Mineral Deposit Model

Not available

Orebody

Not available

Structure

Type: R
Description: Occurrence On East-Dipping Limb Of Large Fold With North-Trending Axis;Kaniksu Batholith,Purcell Trench;Moyie-Leonia Fault

Type: L
Description: North-Northeast Trending Purcell Sills;Vein On Contact Of Sill With Quartzite

Alterations

Alteration Type: L
Alteration: MODERATE

Alteration Type: L
Alteration Text: Chlorite, Fe Stains

Rocks

Name: Diorite
Role: Associated
Age Type: Associated Rock
Age Young: Neoproterozoic

Name: Diorite
Role: Associated
Age Type: Host Rock Unit
Age Young: Neoproterozoic

Name: Diorite
Role: Associated
Age Type: Host Rock
Age Young: Neoproterozoic

Analytical Data

Analytical Data: AVERAGE GRADE OF 7 LBS CU, 5 LBS NI PER TON. DRILL CORE ASSAYS: 3.5% CU, 1.1%NI. ANALYSIS BY BRACHEBUSCH ON PYRRHOTIZED SILL ROCK: 200 PPM NI.

Materials

Ore: Pentlandite
Ore: Chalcopyrite
Ore: Gersdorffite
Ore: Sphalerite
Gangue: Pyrrhotite
Gangue: Hypersthene
Gangue: Quartz
Gangue: Siderite
Gangue: Pyrite

Comments

Comment (Geology): A Petrographic Study Of A Suite Of Samples Taken From The Ore Body Show The Average Density (From Six Samples) To Be 2.985 Grams Per Cubic Centimeter. The Aldridge-Prichard Formation, Of The Precambrian Belt Series Is Intruded By Numerous Diorite And Gabbro Sills Some Of Which Are As Much As 600 Meters Thick.

Comment (Geology): Eight Samples Were Taken Whose Assays Averaged 0.56 Percent In Copper, 0.06 Percent In Nickel, And 0.25 Ounces Of Gold Per Ton. Cobalt Was Not Included In The Assays.

Comment (Deposit): 3-4 Anomalies

Comment (Workings): 7 Tunnels

Comment (Geology): Geol.Desc: Disseminated Sulfides In Mafic Sill, 250 Ft. Thick And Composed Of Hypersthene Gabbro And Uralitized Diorite; Disseminations Of Pyrrhotite And Minor Pentlandite And Chalcopyrite In Its Lower 80 Ft.

Comment (Reserve-Resource): Marginal Cu-Ni Ore Reserves Indicated Because Of Low Tenor

Comment (Reserve-Resource): Reserves Insignificant Because Of Low Tenor.

Comment (Location): Western Base Of Hall Mountain

Comment (Development): 68 Unpatented Claims. Three 30-Ft Ddhs

Comment (Geology): The Three Upper Adits Explore A Quartz Vein In Or Near The Footwall Of A Large Basic Sill. It Was Found To Contain Minor Amounts Of Iron, Lead, And Zinc Sulfides, But In No Place Were The Minerals Sufficiently Concentrated To Even Approach A Commercial Grade. The Lower Tunnels Cut Several Minor Slips And Seams, But No Definite Vein. Instead The Walls Are Heavily Pyrhotitized And Appear To Be Components Of An Extensive Low Grade Ore Body. Microscopic Evidence Indicates That The Sulfides Of The Sill Rock Are The Result Of Concentration By Magmatic Segregation The Evidence That Is Common To All Of The Sulfide-Bearing Samples Includes The Following: Igneous Textures, Inclusion Of Sulfides Within Silicates With The Distinct Corrosion Of The Silicates Along Cleavage Planes And Planes Of Weakness By The Sulfides, And No Apparent Corrosion Of The Sulfides By The Silicates. The Corrosion Of The Silicates By The Sulfides May Be Explained As Follows: During The Latter Stage Of Crystal- Ization All Of The Silicates Were Crystalized While The Sulfides Were Still Molten Due To Their Lower Melting Point. The Sulfides, Descending As Immiscible Droplets To The Base Of The Sill, Were Crystalized And Deuterically Replaced Silicate Minerals. Varying Degrees Of Hydrothermal Alter- Ation Subsequently Produced Sericite And Kaolinite At The Expense Of The Feldspar.

Comment (Deposit): Amount Of Sulfide-Bearing Rocks Is Large, But The Tenor Of Nickel And Copper Is Too Low To Be Of Economic Interest, 1974 Drilling Indicated An 80-Ft-Wide Zone Averaging 7lbs Cu And 5lbs Ni/Ton, And Indications Of About $5/Ton Au Values.

References

Reference (Deposit): Brackebusch,Fred W.,1969,Economic Geology Of The Queen Mountain Area, A Part Of The Purcell Range, Boundary County,Idaho: Unpublished Thesis,Univ.Idaho,76p.

Reference (Deposit): Cornwall, H.R., 1966, Nickel Deposits Of North America: USGS Bulletin 1223, 62 P.

Reference (Deposit): Kiilsgaard,Thor H.,1951,Description Of Some Ore Deposits And Their Relationships To The Purcell Sills, Boundary County,Idaho:Idaho Bureau Of Mines And Geology Pamph; No. 85, 31p.

Reference (Deposit): Lemoine,Denis,1959,Thorite Deposits And General Geology Of The Hall Mountain Area,Boundary County,Idaho:Unpublished Thesis,Univ.Idaho, 68p.

Reference (Deposit): 5) Spokane Chronicle, Mar. 23, 1974; Feb. 14, 1974.

Reference (Deposit): 6) Western Mining News, 1974-75 Directory Of Mines In Idaho (Coeur D'Alenes) And Washington, P. 89.

Reference (Deposit): 1966 Cornwall,H.R., Bulletin1223

Reference (Deposit): 1973 Direxpl Montgomery Mines

Reference (Reserve-Resource): Cornwall, H.R., 1966, USGS Bulletin 1223, P. 42.

Reference (Deposit): 1951 Compile Idaho Bureau Of Mines And Geol. Pamph No. 85

Reference (Deposit): U.S.Bureau Of Mines, Wfoc, Mineral Property File 0160210006.

Idaho Gold

"Where to Find Gold in Idaho" looks at the density of modern placer mining claims along with historical gold mining locations and mining district descriptions to determine areas of high gold discovery potential in Idaho. Read more: Where to Find Gold in Idaho.