The Hart nickel deposit is located approximately 27 km southeast of the City of Timmins, Ontario, Canada in Eldorado Township and about 6 km east of the Redstone Mine.
The ore-body is interpreted to be plunging 20 degrees to the east following a trough-like embayment flanked by sulphide-facies iron formation. This conforms with the classical Kamblada-style komatiite-hosted Ni deposit, in which massive sulphide lenses occupy localized depressions in the paleotopography. Drilling at the Hart project was completed to delineate mineralization down to approximately 460m below surface with a few holes probing to 550m.
A NI 43-101 resource calculation released on October 20, 2008 stated an indicated resource of 1,390,000 tonnes grading 1.50% Ni and 0.1% Cu and an inferred resource of 286,000 tonnes grading 1.36% Ni and 0.09% Cu. These tonnages represent the largest NI 43-101 compliant resource in the Shaw Dome identified to date with an average grade of 1.5% Ni. The resource calculation included drilling only to the 460m level. Mineralization is known to exist down to the 550m level and the resources remain open to depth.
Diamond drilling to date has defined a mineralized body with an average strike length of approximately 265m that can be subdivided into two zones based on sulphide content and mineralized zone width: the upper zone contained within the top 275m below surface, and the lower zone found below this elevation.
The upper zone was largely defined in 2007 and has been the subject of a 25m-30m center in-fill drill program in 2008. The latest drill results have returned very positive intersections including: 1.01% Ni over 7.4m (H-08-81), 1.01% Ni over 5.6m (H-08-78), and 0.48% Ni over 13.8m (H-08-75). These results, in combination with previously released diamond drill hole intersections, have defined a continuously mineralized zone with an average strike length of 275m and an average true width of approximately 4m.
The lower zone, discovered by Northern Sun in 2007, is comprised of a large sulphide pool collected in a pronounced paleotopographical depression. This mineralized zone has been defined over a strike length of 260m, and has an average true width of approximately 14m. The central portion of the zone is characterized by intersections such as 2.15% Ni over 14.55m (H-07-35), 1.19% Ni over 25.55m (H-07-45), 1.15% Ni over 27.4m (H-07-30), 2.51% Ni over 10.4m (H-08-66), and 1.37% Ni over 14.2m (H-07-48). This zone appears to be truncated to the west and at depth by a relatively large gabbroic dyke. This dyke appears to have displaced the mineralization as narrow zones of nickel rich sulphides can be located at the upper contact, as evidenced in H-08-68. The mineralized zone may continue on the far side of the dyke. The eastern margin has been defined, terminating in a barren iron formation.
Near Future Production
The Hart deposit could be Northern Sun’s third nickel mine following the Redstone and most recently the McWatters Mine. The Hart claims have been brought to lease already and the Closure Plan was submitted in 2012.
A preliminary economic assessment (PEA) was completed by Stantec on the Hart Deposit in October 2012. This report used the updated resource model which included recent drill hole information.
The Hart Deposit remains open on strike and at depth.
Further exploration and development will be deferred until the long-term nickel price improves.