The Redstone nickel mine, discovered in 1987, is located 24
kilometers south east of Timmins, Ontario, Canada. Previous operators of
the property mined 276,700 tonnes grading 2.4% nickel ("Ni") from the
upper 213 m of the deposit in the 1989-1996 periods.
Northern Sun dewatered the mine during the fall of 2005, and commenced
production mid 2006. Shrinkage stoping was the traditional mining method
used to exploit the rich veins (typically grading 14% Ni to 32% Ni) in
the footwall contact of the komatiite and the underlying dacite known as
Re-examination of drill data from 2007-2008 and earlier historical
data revealed three mineralized zones roughly parallel to the footwall
R-zone (massive pyrrhotite-pentlandite mineralization that has been the
main target in the mine). These zones are typical of the parallel shoots
known in the Kambalda Nickel Belt of Australia, and are prime
The H-zone (hanging wall zone) occurs in a mineralized horizon that
stratigraphically overlies the R-zone by approximately 20m. The H-zone
has been drilled from the 213m and 244m levels and the following
intersections and grades were obtained: UG7-12 at 11.15% Ni over 0.4m;
UG8-18 at 2.52% Ni over 4.5 m; UG7-04 at 1.97% Ni over 2.95 m; UG8-29 at
4.19%Ni over 1.08 m; and R06-08 which showed 2.26% Ni over 1.85 m.
The E-zone was intersected during 2007 surface drilling in hole
R07-93, which assayed 3.05 m grading 3.77% Ni (including 0.5m grading
19.03% Ni). The E-zone appears to be a secondary shoot of mineralization
occurring approximately 60m east from the R-zone. It lies on the main
Redstone lithological contact between komatiite and footwall dacite and
appears to be a parallel zone. The contact can be traced in outcrop and
by mag and EM surveys. The target remains open to the east and
corresponds well to a 1.5km long EM conductor identified in earlier
The historically known S-zone is a parallel zone located
stratigraphically about 60m above the R-zone. Drill hole R-41
intersected 4.0m of mineralization in the interval 113.4m to 117.4m
grading 1.02 % Ni. There are 4 other historically known drill holes of
similar grades which may have intersected the S-zone.
These three target zones were not included in the resource estimation
stated above and provide additional potential to expand the overall
resource and reserves of the Redstone mine.
Reserves and Resources
The pre-feasibility study for the Redstone Mine was released January
11, 2010. The mineral resource estimate at a cut-off grade of 0.51%
nickel ("Ni") consists of 599,000 tonnes in the Measured and Indicated
categories grading 1.47% Ni and 0.02% copper ("Cu"); and 737,000 tonnes
in the Inferred category grading 1.57% Ni and 0.03% Cu. The Proven and
Probable Mineral Reserves were estimated at 259,900 tonnes with an
average grade of 1.04% nickel ("Ni") using a nickel price of US$15,430
per tonne (US$7.00 per pound) and an exchange rate of $1.00 CDN = $0.90
US. There is a strong potential to increase the Inferred Resources in
the lower zone between 510m and 1150m; and to upgrade the current
Inferred resources to the Indicated category with additional drilling.
The reserves would be positively increased and the life of mine
At the start of the first quarter 2011, the Redstone Mine was place
on care and maintenance. A detailed production plan is currently being
prepared to analyze the accessibility and viability of the stopes above
the 1600 metre level. The Redstone Mine continues to be dewatered in
anticipation of returning to production. An exploration plan is in
progress to identify the mineralization below 1600 metre level.
Further exploration and development will be deferred until long-term nickel prices improve.