The Nickel Rim Depth Cu-Ni-PGE deposit, discovered by Falconbridge
Limited in 1993, illustrates several trends in exploration in the Sudbury
area. Recent discoveries tend to be deep, high grade, footwall hosted,
close to or straddle property boundaries and made using a
multi-disciplinarian exploration approach that integrates economic
considerations with geology, metal geochemistry and geophysics
(borehole EM). The Nickel Rim deposit occurs down dip of Inco's Victor Deep deposit
(4.2 million tonnes at 2.25 per cent Ni, 7.30 per cent Cu) in the eastern
margin of the Sudbury Igneous Complex (SIC) at a depth of 2650 m.
Before commencing drilling an economic evaluation was done to
determine the minimum size needed to be economic at the expected
depths and determine the expected value of an exploration venture. The subsequent surface exploration program discovered a drill
indicated, undiluted mineral inventory of 1.6 million tonnes of 1.58 per
cent Ni, 10.13 per cent Cu, 4.17g/t Pt and 3.50 g/t Pd including 519 000
tonnes of 4.13 per cent Ni, 25.53 per cent Cu, 9.76 g/t Pt and 8.42 g/t Pd.
The deposit is hosted by gneiss, migmatite, gabbro and pseudotachylite
(Sudbury Breccia) 100 m below the base of the SIC.