The Northeast Arm Iron Range is part of the Temagami Greenstone Belt which occurs on the southern margin of the Abitibi Subprovince.

[1] It consists primarily of a banded iron formation that was deposited in an Algoma type volcanic setting 2.7 billion years ago.

[3] The iron and silica mineralization comprising this feature was directly derived from hydrothermal venting associated with major island arc volcanic centres in a Neoarchean ocean.

[4] After deposition, the sediments were subsequently compressed, deformed and uplifted to form the present-day banded iron formation.

[1] Iron-bearing rocks were noted near the west end of Turtle Lake in 1888 while topographical work and geological reconnaissance was being done adjacent to Temagami.

[2][7] Two ore samples grading 42.89% and 38.94% iron were obtained by O'Connor in 1902 for mineral processing tests, the results of which showed that it was possible to produce a concentrate from this deposit.

[8] Caldwell engaged in exploratory work of the Northeast Arm Iron Range in 1905 which involved diamond drilling, trenching and cross-cutting of the ore body.