North American Nickel Inc.'s three-dimensional modelling of SkyTEM helicopter time domain electromagnetic (EM) data collected last fall over parts of its Maniitsoq project in southwest Greenland is complete and has identified three high priority targets for follow-up this summer. Details on each are discussed in the sections below.
Highlights:
-- Target B1-L - modeled as a 330 x 100 m flat-lying conductor located 160 m below surface within a norite intrusion. The conductor is untested but past shallow drilling 100 to 150 m above the conductor intersected weakly disseminated, nickeliferous sulphides grading up to 0.52% Ni and 0.26% Cu over 12.94 m, demonstrating that mineralizing processes were at work in the intrusion.
-- Target B1-B - 700 m long, untested, near surface conductive zone. The characteristics and orientation of the conductor vary considerably along strike suggesting it is not formational. Magnetic data suggests that it is hosted in a large (2.5 x 1.0 km) norite body.
-- Target B1-J - 170 m long by 16 m wide conductor that comes to surface and is directly coincident with the Imiak Hill showing, the most significant nickel occurrence discovered to date in our Maniitsoq licence area. The model shows that the Imiak Hill mineralization strikes parallel to most of the historical drilling and therefore has not been properly tested. The model has very limited dip extent (21 m), but the best intersection on the showing (9.85 m averaging 2.67% Ni and 0.60%
Cu) occurs 130 m below surface indicating that strong mineralization at surface is masking mineralization at depth.
North American Nickel CEO Rick Mark states: "The Maniitsoq project is progressing remarkably well. Our primary objective in 2011 was to employ today's airborne EM survey technology in this highly prospective nickel belt. Fifteen years ago Falconbridge and Cominco used fixed wing aircraft and the technology of the day searching for conductive bodies to indicate drill targets. It simply didn't work. After flying only 8% of our Maniitsoq license, we have proven that modern helicopter EM is much more effective than previous techniques used in this 75 km long belt of nickeliferous norites. Today's release describes, in detail, the first three targets we have identified in this potential nickel camp."
Background
As described in NAN news releases dated December 6 and 8, 2011, SkyTEM helicopter EM and magnetic surveys flown over two flight blocks covering approximately 8% of the 4,841 km2 Maniitsoq project, detected twenty five anomalous target zones. The location of the project and the flight blocks are shown in figures 1 and 2.
The purpose of the EM modeling discussed in this news release was to determine the characteristics of the anomalies in three dimensions in preparation for follow-up prospecting and drilling. All three high priority targets are located within flight block 1 (Figure 3).
Target B1-L
The target corresponds to the Spotty Hill showing, which consists of weak (less than 1 to 2%) disseminated sulphide mineralization in a lenticular exposure of norite roughly 400 m long and 150 m wide. It was discovered in the early 1960's by Kyrolitselskabet Oresund A/S who tested it with five very shallow (less than 60 m long) holes. All five intersected norite with weak, disseminated, nickeliferous sulphide mineralization. The best intersection was 12.94 m averaging 0.52% Ni and 0.26% Cu in norite containing about 5% sulphide.
The SkyTEM survey detected a moderate strength EM anomaly directly over the showing. Modeling indicates that the anomaly is produced by a flat-lying conductor, approximately 330 m long by 100 m wide, located at a depth of 160 m below surface, which is over 100 m below the deepest hole on the showing (figures 4 and 5).
Target B1-B
This target was modeled as a series of six conductive plates ranging in thickness from 9 to 43 m that occur over a distance of about 700 m. In Figure 6 it can be seen that the strike and dip of the plates vary considerably along the length of the target suggesting that it is not a simple stratigraphic conductor. It should be noted that the plates in Figure 6 have been truncated along their strike length in order to show their orientations more clearly. In most cases the plates actually overlap along strike; although the large gap in the middle of the target does appear to be real.
The target is situated within a 2.5 km by 1.0 km magnetic feature interpreted to be a norite intrusion. Some of the model plates come very close to surface and it may be possible to determine the source of the anomaly through surface prospecting which will be carried out this season.
Target B1-J
This target corresponds to the Imiak Hill showing and models as a 172 m long by 16 m thick plate that comes to surface and has a depth extent of just 21 m (figures 7 and 8). Clearly, the mineralization continues well below 21 m as evidenced by hole Im-9, which intersected 9.85 m of massive to semi-massive sulphide averaging 2.67% Ni and 0.60% Cu at a depth of 130 m vertically below surface. It therefore appears that highly conductive material at surface is masking responses from deeper mineralization, which is to be expected. The modeling results are significant, however, in that they show that most of previous drilling at Imiak was oriented parallel to strike and that, despite the numerous shallow drill holes, many of which intersected significant mineralization (see table in Figure 8), the zone has not been properly tested. Two or three holes oriented perpendicular to strike followed by down-hole 3-component EM surveying is required to get a better interpretation of the potential of this zone.
Electromagnetic Modeling Program
Nineteen of the twenty five conductive target zones identified in 2011 were modeled by Condor Consulting of Lakewood, Colorado using Maxwell, a program developed by EMIT of Perth, Australia for analysis of EM geophysical data. Maxwell produces simplified, three-dimensional conductive plate models that mimic the observed response from the EM anomaly being analyzed. This type of modeling is a powerful exploration tool but it is important to bear in mind the limitations of the method, which include the following:
-- The model is limited to plates and therefore complex geometries can only be very roughly approximated.
-- In most cases there is not a single unique model that fits the observed data, so the operator must make some assumptions about the conductor.
-- In airborne datasets, such as the one being interpreted here, a strong EM response near surface will drown out responses from deeper sources and the top of a conductor will be much better defined than the bottom.
Qualified Person
All technical information in this release has been reviewed by Dr. Mark Fedikow, P.Geo, who is the Qualified Person for the Company and President and Chief Operating Officer, North American Nickel Inc.
