20. Banded iron formation (Magnetite)

Banded Iron Formation (BIF)

Sedimentary rock consisting of interbedded grey specular magnetite and red jasper layers. Archean in age. Algoma-type BIF. 

Mined at Sherman Mine in Temagami, Northeastern Ontario. This sedimentary rock was worked as ore to supply the steel mills of Dofasco. When the mine was active, over one million tons of iron pellets were shipped annually down to Dofasco in Hamilton. The deposit was first investigated in 1904 and 1905. Sherman Mine was brought into production in 1968 and closed in 1990.

Close-up of banded iron formation (magnetite)
Banded iron formation (magnetite) sample from the side