True Fissure Mine

The True Fissure Mine is a lead and silver mine located in Mineral county, Montana at an elevation of 4,400 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

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: True Fissure Mine

Commodity

Primary: Lead
Primary: Silver
Secondary: Copper

Location

State: Montana
County: Mineral
District: Unorganized

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.

Holdings

Not available

Workings

Type: Underground

Ownership

Owner Name: Day Mines, Inc.

Production

Not available

Deposit

Record Type: Site
Operation Category: Occurrence
Operation Type: Unknown
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: Coeur D'Alene Mountains

Mineral Deposit Model

Not available

Orebody

Not available

Structure

Type: R
Description: A Major Structural Grain Trends Nw And Consists Of Subparallel Faults And Folds. Major Fault Is The Osburn. This Fault Seems To Demarcate A Change In Folding Form With Folds To The North Showing Signs Of More Intense Structural Deformation Than Those To The South.

Type: L
Description: Owing To Its Proximity To The Osborn Fault Beds Are Greatly Deformed And Are In Tight, Overturned, Nearly Isoclinal Folds

Alterations

Alteration Type: L
Alteration Text: Hydrothermal Bleaching Is Common Within A Belt Approx 1 Mi Wide Along The North Side Of The Osburn Fault Zone. It Has Been Used As A Guide To Ore Deposits.

Rocks

Name: Quartzite
Role: Host
Age Type: Host Rock
Age Young: Neoproterozoic

Analytical Data

Analytical Data: SAMPLES TAKEN FROM THE LOWER ADIT ARE REPORTED TO CONTAIN 1-3 OZ/TON AG AND 5-10% OF LEAD

Materials

Ore: Chalcopyrite
Ore: Galena
Gangue: Siderite
Gangue: Hematite
Gangue: Quartz
Gangue: Pyrite

Comments

Comment (Location): ON EAST TWIN CREEK.

Comment (Deposit): VEIN STRIKES NORTH WHICH IS UNUSUAL COMPARED TO OTHER VEIN TRENDS WITHIN THE REGION.

Comment (Workings): WORKINGS CONSIST OF 3 ADITS ONLY 2 OF WHICH ARE ACCESSIBLE.

References

Reference (Analytical Data): SRC.REF: WALLACE, R. E. AND HOSTERMAN, J. W., 1956 : US GEOLOGICAL SURVEY BULL. 1027-M

Reference (Deposit): WALLACE, R. E. AND HOSTERMAN, J. W., 1956 , RECONNAISSANCE GEOLOGY OF WESTERN MINERAL COUNTY MONTANA: US GEOLOGICAL SURVEY BULL. 1027-M, P. 607 .

Reference (Deposit): CONSV. DIV. COMP. DATE, 02-15-1963

Principal Gold Districts of Montana

In Montana, 54 mining districts have each have produced more than 10,000 ounces of gold. The largest producers are Butte, Helena, Marysville, and Virginia City, each having produced more than one million ounces. Twenty seven other districts are each credited with between 100,000 and one million ounces of gold production. Read more: Principal Gold Districts of Montana.