Ni-Cu dominant magmatic deposits
The Raglan Mining Company, a wholly
owned subsidiary of Falconbridge Ltd., began open-pit
and underground production in 1998, after an initial investment
of $500 million in the mine, concentrator and infrastructures. The
mineralization is composed of several massive sulfide lenses associated
with Proterozoic ultramafic flows that extend along the contact
between tholeiites and sediments of the Povungnituk Group and komatiites
of the Chukotat Group. The average grades from 23 samples taken
at the Raglan mine were 4.49% Ni, 1.22% Cu, 2.9 g/t Pd, and 1.3
g/t Pt. Reserves at the mine are 9.0 Mt of ore at 3.06% Ni and 0.89%
Cu. Nine zones are recognized over a distance of 55 km in the area
of the mine (Donaldson, Boundary, West Boundary, 13–15, 5–8,
Katinniq, 2–3, East Lake, and Cross), as shown in Figure 1.
The sulfides are associated with pentlandite and pyrrhotite. Chalcopyrite,
magnetite and pyrite are also associated with Cu and PGEs.