The Little Johnnie Mine is a thorium mine located in Gunnison county, Colorado at an elevation of 8,921 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
Elevation: 8,921 Feet (2,719 Meters)
Commodity: Thorium
Lat, Long: 38.32167, -107.08611
Map: View on Google Maps
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Little Johnnie Mine MRDS details
Site Name
Primary: Little Johnnie Mine
Secondary: Unpatented Claims: Little Johnnie Nos. 1-2
Secondary: Little Johnnie Extension
Secondary: Cathey Nos. 1-5
Secondary: Charley Nos. 1-5
Commodity
Primary: Thorium
Tertiary: REE
Location
State: Colorado
County: Gunnison
District: Goose Creek District
Land Status
Land ownership: BLM Administrative Area
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: John A. Mcgregor
Home Office: Powderhorn
Years: 1962 -
Production
Not available
Deposit
Record Type: Site
Operation Category: Occurrence
Deposit Type: Vein
Operation Type: Unknown
Discovery Year: 1949
Discovery Method: Ore-Mineral In Place
Years of Production:
Organization:
Significant: N
Deposit Size: S
Physiography
General Physiographic Area: Rocky Mountain System
Physiographic Province: Southern Rocky Mountains
Mineral Deposit Model
Not available
Orebody
Form: TABULAR
Structure
Type: R
Description: Gunnison Uplift, San Juan Volcanic Field
Type: L
Description: Gunnison Gold Belt, Iron Hill Alkalic Complex, Tolvar Peak Stock
Alterations
Not available
Rocks
Name: Syenite
Role: Associated
Age Type: Associated Rock
Age Young: Late Ordovician
Name: Syenite
Role: Associated
Age Type: Host Rock
Age Young: Neoproterozoic
Analytical Data
Analytical Data: 0.009, 0.05
Analytical Data: 0.15, 0.84
Analytical Data: 0.031, 0.17
Analytical Data: 0.034, 0.19
Analytical Data: 0.019, 0.10
Analytical Data: 0.88, 4.9
Analytical Data: 0.11, 0.61
Analytical Data: 0.12, 0.67
Analytical Data: 0.045, 0.25
Analytical Data: ADAMS AND MOORE (1951) GIVE CHEMICAL ANALYSIS OF VEIN MATERIAL AS 2.29% TH02 AND 0.50% RARE-EARTH OXIDE. RADIOMETRIC ANALYSES TABULATED BY OLSON AND WALLACE (1956) (EACH SET OF VALUES IS % EQUIV URANIUM AND CALCULATED % TH02 ASSUMING THAT ALL RADIOACTIVITY IS DUE TO TH): 0.13, 0.73
Analytical Data: 0.014, 0.08
Analytical Data: 0.20, 1.12
Materials
Ore: Thorite
Gangue: Xenotime
Gangue: Quartz
Gangue: Goethite
Gangue: Chlorite
Gangue: Clinozoisite
Gangue: Allophane
Gangue: Rutile
Gangue: Hematite
Gangue: Tourmaline
Gangue: Barite
Gangue: Apatite
Comments
Comment (Location): ON NORTH SIDE OF MILKRANCH GULCH DRAINAGE BASIN AND EAST OF OLD LOT MINE. ; INFO FROM LAND.ST :1976
Comment (Deposit): THORIUM VEINS IN THIS AREA ARE ONE OF FOUR ENVIRONMENTS OF TH OCCURRENCE KNOWN IN POWDERHORN-IRON HILL AREA AND ARE PROBABLY RELATED TO EMPLACEMENT OF LATE PRECAMBRIAN SYENITES NORTH AND WEST OF IRON HILL AND OF YOUNGER LATE PRECAMBRIAN OR CAMBRIAN CARBONATITES AT IRON HILL. FOLIATION OF DUBOIS GREENSTONE FELSITE AND SEVERAL LAYERS OF HORNBLENDE SCHIST AND AMPHIBOLITE COUNTRY ROCK TREND GENERALLY N 55 TO 60 E, 80 TO 90 NW. OLSON AND WALLACE (1956) DESCRIBE SEQUENCE AS QUARTZ-BIOTITE SCHIST AND QUARTZITE, METARHYOLITE PORPHYRY, AMPHIBOLITE DIKES AND BODIES ALL CUT BY SMALL FAULTS, BY SYENITE DIKES AND LARGE NW-TRENDING GABBRO DIKE, AND BY QUARTZ, CARBONATE, SODA-AMPHIBOLE, AND BRECCIA VEINS. POORLY EXPOSED VEIN IS MINERALIZED FAULT TRENDING N 65 E, DIPPING WITHIN 10 DEG OF VERTICAL. VEIN RANGES FROM UNDER 6 INCHES TO 5 FT WIDE, WITH AVERAGE NOT EXCEEDING 2 FT. VEIN MAY EXTEND FARTHER NE REAPPEARING AS TRACHYTE PORPHYRY DIKE BUT IS SEPARATED FROM IT BY TWO NW-TRENDING CAMBRO-ORDOVICIAN
Comment (Deposit): DIABASE DIKES. MINERALOGY CHARACTERIZED BY SUBHEDRAL TO ANHEDRAL MASSES OF THORITE OR THOROGUMMITE, EUHEDRAL CRYSTALS OF HEMATITE PARTLY ALTERED TO GOETHITE, COARSE-GRAINED BARITE, AND POSSIBLE ACCESSORY XENOTIME (Y RARE EARTH).
Comment (Workings): 40-FT LITTLE JOHNNIE NO. 1 TUNNEL; 389-FT LITTLE JOHNNIE NO. 2 TUNNEL; SMALL PROSPECT SHAFT; SURFACE CUTS.
References
Reference (Deposit): HEDLUND, D.C., AND OLSON, J.C., 1975, GEOLOGIC MAP OF THE POWDERHORN QUADRANGLE, GUNNISON AND SAGUACHE COUNTIES, COLORADO: USGS MAP GQ-1178.
Reference (Deposit): HEDLUND, D.C., AND OLSON, J.C., 1961, FOUR ENVIRONMENTS OF THORIUM-, NIOBIUM-, AND RARE-EARTH-BEARING MINERALS IN THE POWDERHORN DISTRICT OF SOUTHWESTERN COLORADO: USGS PROF. PAPER 424-B, P. B283-B286.
Reference (Deposit): OLSON, J.C., AND HEDLUND, D.C., 1981, ALKALIC ROCKS AND RESOURCES OF THORIUM AND ASSOCIATED ELEMENTS IN THE POWDERHORN DISTRICT, GUNNISON COUNTY, COLORADO: USGS PROF. PAPER 1049-C.
Reference (Deposit): OLSON, J.C., AND WALLACE, S.R., 1956, THORIUM AND RARE-EARTH MINERALS IN POWDERHORN DISTRICT, GUNNISON COUNTY, COLORADO: USGS BULL. 1027-0.
Reference (Deposit): NELSON-MOORE, J.L., AND OTHERS, 1978, RADIOACTIVE MINERAL OCCURRENCES OF COLORADO AND BIBLIOGRAPHY: CGS BULL. 40, P. 175.
Reference (Deposit): ADAMS, J.W., AND MOORE, F.B., 1951, AEC PRELIM. RECON. REPT. RR-95.
Reference (Deposit): COLORADO DIV. MINES INF. REPTS.
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