Commodities
PrimaryIron
Commodity typeM
Deposit
Deposit typeSecondary Enrichment
Model241: Superior Fe (BC name is Lake Superior & Rapitan types iron-formation)
Deposit sizeU
Ore controlStratigraphically controlled, fault related.
Materials
Ore mineralsHematite, Goethite
GangueChert, Pyrite, Siderite, Stilpnomelane, Chlorite, Mica
Geology
Host rockIron Formation · Riverton Iron-Formation
AlterationChert and siderite to hematite and goethite in oxidation zones
Economic & production
Development statusPast Producer
First production1935
Last production1967
Identification
Deposit ID10106119
MRDS IDW028932
Alternate namesDuff Mine
RegionNA
Data scoreB
Coordinates46.07306, -88.63561
References
JAMES, H.L., DUTTON, C.E., PETTIJOHN, F.J., WIER, K.L., 1968, GEOLOGY AND ORE DEPOSITS OF THE IRON RIVER, CRYSTAL FALLS DISTRICT, IRON COUNTY, MICHIGAN. WASHINGTON, U.S. GOVT. PRINTING OFFICE, 1968. PP. 45-56, 88-110.LAKE SUPERIOR IRON ORE ASSOCIATION, 1952, LAKE SUPERIOR IRON ORES (2ND ED.): CLEVELAND, OHIO. P. 116.JOHNSON, A.M. AND GROTH, E.H., 1998, INVENTORY OF UNDERGROUND MINES, IRON COUNTY, P. 186-188, MICHIGAN DEPARTMENT OF NATURAL RESOURCES.