Picket Pin

The Picket Pin is a platinum and palladium mine located in Sweet Grass county, Montana at an elevation of 10,000 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: Picket Pin

Commodity

Primary: Platinum
Primary: Palladium
Secondary: Copper
Secondary: Nickel
Tertiary: Antimony
Tertiary: Cobalt
Tertiary: Iridium
Tertiary: Gold
Tertiary: Arsenic

Location

State: Montana
County: Sweet Grass
District: In Stillwater Complex

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

Not available

Ownership

Owner Name: Anaconda Co.
Years: 1980 -

Production

Not available

Deposit

Record Type: Site
Operation Category: Occurrence
Operation Type: Unknown
Discovery Year: 1936
Years of Production:
Organization:
Significant: N
Deposit Size: M

Physiography

General Physiographic Area: Rocky Mountain System
Physiographic Province: Middle Rocky Mountains

Mineral Deposit Model

Not available

Orebody

Form: LENSES, PODS, PIPES, DISSEMINATED

Structure

Type: R
Description: The Stillwater Complex Is Exposed Along The Northern Margin Of The Beartooth Uplift, One Of Several Laramide Basement-Cored Ranges That Make Up The Rocky Mountain Foreland Of South-Central Montana (Foose And Others, 1961: Kulik And Schmidt, 1988)

Type: L
Description: Cross Faults Offset Sulfide Bearing Zone

Alterations

Alteration Type: L
Alteration Text: Plagioclase Is Altered To Clinozoisite-Epidote, Pyroxene To Chlorite-Calcite-(Talc)- Magnetite-Quartz, Pyrrhotite To Pyrite

Rocks

Name: Anorthosite
Role: Host
Age Type: Associated Rock Unit
Age Young: Neoarchean

Name: Anorthosite
Role: Host
Age Type: Host Rock
Age Young: Early Cretaceous

Analytical Data

Analytical Data: 6.1% NI, 14.6% CU, 0.2% CO, 1.4 PPM IR, 35 PPM PT, 44 PPM PD, 3.6 PPM AU IN SULFIDE-RICH SAMPLE (BOUDREAU AND MCCALLUM). 0.58% CU, 0.21% NI, 2.5 PPM PT (+IR, RU, RH), 2.5 PPM PD, 0.22 PPM AU (HOWLAND AND OTHERS). OZ/TON VALUES CONVERTED TO PPM

Materials

Ore: Sperrylite
Ore: Chalcopyrite
Ore: Pyrite
Ore: Pyrrhotite
Ore: Pentlandite
Gangue: Talc
Gangue: Calcite
Gangue: Chlorite
Gangue: Plagioclase
Gangue: Apatite
Gangue: Quartz
Gangue: Graphite
Gangue: Magnetite

Comments

Comment (Geology): MINERALIZING FLUIDS WERE SILICA AND ALKALI RICH WITH HCL AND HF. A LACK OF FE AND TI OXIDES INDICATES THE SULFIDES FORMED AT HIGHER SULFUR FUGACITIES. AGE OF STILLWATER COMPLEX IS 2,705 +/- 4 MA BASED ON U-PB SYSTEMATICS ON ZIRCON-BADDELEYITE (PREMO AND OTHERS, 1990)

Comment (Deposit): SULFIDE ZONE IS STRATIFIED WITHIN UPPER 150 M OF ANORTHOSITE SUBZONE II AND CAN EXTEND UP TO TROCTOLITE BUT GENERALLY ENDS ABOUT 10 M FROM TOP OF ANORTHOSITE WHERE THERE IS A DISTINCT TEXTURAL CHANGE. MINERALIZING SOLUTIONS PERCOLATED UPWARD DURING SOLIDIFICATION OF ANORTHOSITE. HOWLAND AND OTHERS NOTED THAT THE SULFIDES ARE INTERSTITIAL TO SILICATES AND PARTLY REPLACE THEM. DEPOSIT HAS HIGHER CU AND LOWER NI THAN J-M REEF; UNPUBLISHED MODEL NAME: PICKET PIN MINERALIZATION.

Comment (Workings): SAMPLING ONLY

Comment (Location): UNSURVEYED. IN CUSTER AND GALLATIN NATIONAL FORESTS. LOCATION GIVEN IS SUMMIT OF PICKET PIN MOUNTAIN; HOWEVER, DEPOSIT IS TRACEABLE ALONG STRIKE FOR 22 KM

Comment (Development): PRESENCE OF MINERALIZATION WAS KNOWN FROM NEAR HEAD OF NORTH FORK PICKET PIN CREEK IN 1930'S. SOIL GEOCHEMICAL SAMPLING PROGRAM IN 1968 DEFINED AREA OF MINERALIZATION AROUND PICKET PIN.

References

Reference (Deposit): BOUDREAU, A.E., AND MCCALLUM, I.S., 1986, INVESTIGATIONS OF THE STILLWATER COMPLEX: III. THE PICKET PIN PT/PD DEPOSIT: ECONOMIC GEOLOGY, V. 81, P. 1953-1975.

Reference (Deposit): ZIENTEK, M.L., 1993, MINERAL RESOURCE APPRAISAL FOR LOCATABLE MINERALS: THE STILLWATER COMPLEX, IN HAMMARSTROM, J.M., ZIENTEK, M.L., AND ELLIOTT, J.E., EDS., MINERAL RESOURCE ASSESSMENT OF THE ABSAROKA-BEARTOOTH STUDY AREA, CUSTER AND GALLATIN NATIONAL FORESTS, MONTANA: U.S. GEOLOGICAL SURVEY OPEN-FILE REPORT 93-207, P. F1-F83.

Reference (Deposit): HOWLAND, A.L., PEOPLES, J.W., AND SAMPSON, EDWARD, 1936, THE STILLWATER IGNEOUS COMPLEX AND ASSOCIATED OCCURRENCES OF NICKEL AND PLATINUM GROUP METALS: MONTANA BUREAU OF MINES AND GEOLOGY MISCELLANEOUS CONTRIBUTION 7, 15 P.

Reference (Deposit): PREMO, W.R., HELZ, R.T., ZIENTEK, M.L., AND LANGSTON, R.B., 1990, U-PB AND SM-ND AGES FOR THE STILLWATER COMPLEX AND ITS ASSOCIATED SILLS AND DIKES, BEARTOOTH MOUNTAINS, MONTANA: IDENTIFICATION OF A PARENT MAGMA?: GEOLOGY, V. 18, P. 1065-1068.

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.