Commodities
PrimaryIron
Commodity typeM
Deposit
Deposit sizeS
WorkingsSurface/Underground
Orebody formONE OF THE MAIN ORE BODIES IS CRUDELY DOME SHAPED, THE OTHER IS AN ELONGATED LENSE IN PLAN BUT HOOK-SHAPED IN CROSS SECTION
Materials
Ore mineralsMagnetite, Martite
GangueActinolite, Andradite, Apatite, Barite, Bornite, Calcite, Chalcopyrite, Chlorite, Dolomite, Epidote, Fluorite, Galena, Pyrite, Pyroxene, Quartz, Sericite, Tremolite
Geology
Host rockConglomerate,Andesite · Andesite Porphyry
Associated rockAndesite
StructureSt. Francois Mountains, Ozark Dome., Many Near-Vertical Strike-Slip Faults Intersect The Ore Body, But Most Have Displacements Less Than A Foot. Faults Are Especially Common Along The Late Andesite Dikes With Movement Both Preceding And Following The Intrusion. All The Faults Are Precambrian. Two Sets Of Joints That Strike Ne And Nw Are The Most Common. Dips Are 82 Deg Nw And 87 Deg Ne Respectively.
Tectonic settingSt. Francois Mountains
AlterationRocks On The Upper Portion Of Big Mountain Exhibit Everywhere The Effects Of Extreme Alteration. Wall Rocks Are Altered To Chlorite, Epidote And Sericite.
Economic & production
Development statusPast Producer
First production1845
Identification
Deposit ID10072189
MRDS IDW016789
RegionNA
Data scoreB
Coordinates37.70506, -90.63481
References
SRC.REF: LAKE, M.C., 1933 , 16 TH INT. GEOL. CONG. GUIDEBOOK 2 , P. 64.CRANE, G.W., 1912 , THE IRON ORES OF MISSOURI: MO. BUREAU OF MINES AND GEOL., 2D SER., V. 10 , P. 108 - 120 .MURPHY, JOHN E., AND OHLE, ERNEST L., 1968 , THE IRON MOUNTAIN MINE, IRON MOUNTAIN, MISSOURI, IN: RIDGE, J.D., ORE DEPOSITS OF THE UNITED STATES, 1933 - 1967 (GRATON-SALES VOLUME): NEW YORK, AM. INST. MINING, METALL. PETROLEUM ENGINEERS, V. 1 , P. 288 - 302.LAKE, M.C. 1933 , THE IRON-ORE DEPOSITS OF IRON MOUNTAIN, MISSOURI, IN: 16TH INT. GEOL. CONG. GUIDEBOOK 2 , P. 56 - 67WINSLOW, ARTHUR, HAWORTH, E., NASON, F., 1894 , A REPORT ON THE IRON MOUNTAIN SHEET INCLUDING PORTIONS OF IRON, ST. FRANCOIS AND MADISON COUNTIES: MO. GEOL. SURV., 1 SERV., V. 9 , SHEET REPORT NO. 3 , P. 56 - 61.1910 DIREXPL 3 HOLES INDICATE A CONSIDERABLE THICKNESS OF CONGLOMERATE ORE. 50 FT AND 8 IN OF SOLID VEIN ORE ISENCOUNTERED IN ONE HOLE.DIREXPL OLD IRON MOUNTAIN COMPANY DRILLED 3 HOLES IN THE FOOT WALL OF THE BIG PIT AT LITTLE MOUNTAIN AND CUT CONSIDERABLE ORE.CRANE, G.W., 1912 , THE IRON ORES OF MISSOURI: MO. BUREAU OF MINES AND GEOL., 20 SER., V. 10 , P. 108.