Overview
Three Bluffs occurs approximately central within the Committee Bay Greenstone Belt, 270 km northeast of Meadowbank and 100 km northwest of Wager Bay.
The deposit is hosted within a package of intercalated iron formation, komatiite, felsic volcanic, and greywacke that has been intruded by tonalite and diorite plutons and subject to multiple phases of deformation, metamorphism and tectonism.
Gold mineralization at Three Bluffs occurs within a sub-vertical, 5 to 50 metre wide shear zone referred to as the Walker Lake Trend (‘WLT’). Approximately 4 km of the WLT which has been drill-tested to date contains anomalous gold to a depth of 550 vertical metres. Significant gold mineralization occurs within a structurally thickened fold closure of iron formation at the eastern end of the WLT. Additionally, structurally controlled, plunging lenses of high grade gold mineralization occur within this shear zone in the North, South, West, Antler, and Hayes lodes.
Gold mineralization at Three Bluffs occurs within zones of silica ± sericite alteration within intensely deformed iron formation and greywacke. Gold occurs commonly as fine to coarsely disseminated grains often affiliated with pyrrhotite. Metallurgical test work completed on mineralized material show that gold recoveries of up to 65% can be achieved using gravity separation. This recovery increases to up to 93% when gravity is used followed by successive flotation and cyanide leaching.
Drill Highlights
Hole ID |
East |
North |
Dip |
Azimuth |
From |
To |
Length |
True thickness |
Au grade |
Grade x true thickness |
|
Local Grid |
degrees |
degrees |
metres |
metres |
metres |
metres |
g/t |
Gram metres |
04TB010 |
7582 |
4676 |
-45.0 |
180 |
13.70 |
82.00 |
68.30 |
48.29 |
7.37 |
355.90 |
07TB048 |
7610 |
4611 |
-45.0 |
0 |
34.33 |
58.00 |
23.67 |
16.74 |
19.44 |
325.43 |
07TB049 |
7581 |
4562 |
-48.0 |
0 |
87.00 |
96.34 |
9.34 |
6.24 |
38.59 |
240.80 |
04TB009 |
7730 |
4739 |
-44.0 |
180 |
55.60 |
133.97 |
78.37 |
56.37 |
4.55 |
256.48 |
08TB077 |
6440 |
4782 |
-42.0 |
0 |
37.00 |
50.97 |
13.97 |
10.38 |
23.53 |
244.24 |
03T005 |
7582 |
4676 |
-45.0 |
180 |
54.60 |
67.50 |
12.90 |
9.12 |
24.83 |
226.45 |
03T006 |
7700 |
4712 |
-45.0 |
180 |
60.49 |
89.07 |
28.58 |
20.21 |
10.77 |
217.66 |
10TB082 |
7311 |
4607 |
-43.7 |
0 |
7.00 |
49.14 |
42.14 |
30.47 |
5.88 |
179.16 |
07TB054 |
7671 |
4625 |
-46.0 |
0 |
26.00 |
63.00 |
37.00 |
25.70 |
6.59 |
169.36 |
10TB096 |
7460 |
4607 |
-45.0 |
0 |
11.59 |
31.00 |
19.41 |
13.72 |
12.51 |
171.64 |
11TB128 |
7040 |
4529 |
-55.5 |
0 |
261.00 |
274.00 |
13.00 |
7.36 |
18.13 |
133.44 |
04TB019 |
7671 |
4576 |
-42.0 |
0 |
82.16 |
95.20 |
13.04 |
9.69 |
17.04 |
165.12 |
11TB122 |
6980 |
4565 |
-56.0 |
0 |
225.00 |
243.00 |
18.00 |
10.07 |
12.34 |
124.26 |
10TB092 |
7730 |
4636 |
-44.0 |
0 |
40.00 |
79.00 |
39.00 |
28.65 |
5.52 |
158.15 |
07TB045 |
7611 |
4578 |
-50.0 |
0 |
62.04 |
103.00 |
40.96 |
26.33 |
5.10 |
134.28 |
04TB033 |
7341 |
4651 |
-44.0 |
180 |
35.88 |
51.34 |
15.46 |
11.12 |
13.44 |
149.45 |
07TB046 |
7611 |
4578 |
-45.0 |
0 |
53.00 |
103.00 |
50.00 |
35.35 |
3.84 |
135.74 |
11TB104 |
6920 |
4629 |
-43.0 |
0 |
108.00 |
133.00 |
25.00 |
18.28 |
7.34 |
134.18 |
04TB007 |
7640 |
4697 |
-45.0 |
180 |
70.44 |
109.75 |
39.31 |
27.80 |
4.66 |
129.55 |
11TB107B |
6981 |
4600 |
-62.0 |
0 |
188.00 |
200.00 |
12.00 |
5.63 |
15.00 |
84.45 |
Notes: Coordinates and azimuth are based on local grid, true thickness has been calculated assuming a vertical dip of mineralization
Mineral Resource
Based on 58,222 m of drilling completed to date the mineral resource at Three Bluffs comprises:
- An indicated mineral resource of 4.32 Mt grading 4.91 g/t Au (683,000 oz)
- An inferred mineral resource of 5.52 Mt grading 5.43 g/t Au (965,000 oz).
THREE BLUFFS MINERAL RESOURCES AS OF APRIL 2013 |
Class |
Type |
Cut-Off |
Tonnes |
Gold Grade |
Contained Gold |
|
|
(g/t) |
(tonnes) |
(g/t Au) |
(oz Au) |
Indicated |
Open Pit |
1.35 |
3,600,000 |
4.81 |
557,000 |
Underground |
2.50 |
716,000 |
5.46 |
126,000 |
TOTAL INDICATED |
|
4,320,000 |
4.91 |
683,000 |
Inferred |
Open Pit |
1.35 |
1,000,000 |
5.24 |
169,000 |
Underground |
2.50 |
4,520,000 |
5.48 |
796,000 |
TOTAL INFERRED |
|
5,520,000 |
5.43 |
965,000 |
Resource modelling and estimation was completed by independent mining and geology consultants Roscoe Postle and Associates (‘RPA’) in accordance with the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) “Estimation of Mineral Resource and Mineral Reserve Best Practice Guidelines” and are disclosed in accordance with National Instrument 43-101. For additional information please see North Country Gold Corp. press release dated 23rd April 2013.
- A total of 17 domains utilized in grade estimation of the 0.50g/t wireframes and 16 domains for the 1.0 g/t wireframes, Au capping by domain from 75 g/t Au to 30 g/t Au
- Block grade estimation of 0.50 g/t and 1.00 g/t wireframes utilizing ID3 interpolation
- Block grade estimation for 0.50 g/t and 1.0 g/t wireframes performed by successive search ellipsoids with first pass of 15m x 15m x 5m, second pass 30m x 30m x 10m and third pass 75m x 75m x 20m
- Open pit resources (inside whittle) are estimated at a pit discard grade of 1.35 g/t Au with 93% Au recovery utilizing a long term gold price of US$1,500 per ounce, whittle pit shell on the 0.50g/t block model was utilized to constrain the open-pit resources
- Underground resources constrained from 1.0 g/t wireframe block model below the optimized Whittle pit using a 2.5 g/t block cut-off
- Numbers may not add-up due to rounding
- Prior resources for Three Bluffs were completed by Roscoe Postle Associates Ltd in April of 2012 (see press release dated April 4th, 2012 and the Technical Report on the Three Bluffs Project, Nunavut Territory, Canada filed on Sedar, May 18, 2012)
- Mineral resources are not mineral reserves and do not have demonstrated economic viability
- The quantity and grade of reported Inferred resources are uncertain in nature and there has been insufficient exploration to classify these Inferred resources as Indicated or Measured, and it is uncertain if further exploration will result in upgrading them to an Indicated or Measured category
- There are no known legal, political, environmental, or other risks that could materially affect the potential development of the mineral resources
Additional Mineral Potential from Underground Targets
North Country believes there is excellent potential to delineate an additional 4.5 to 7.5 Mt grading between 3.8 to 7.3 g/t Au (550,000 to 1,736,000oz) by extending high grade plunging mineralized shoots at Three Bluffs (West, North and South) and Antler to depth (See Figure).
Please note that the potential quantity and grade is conceptual in nature as there has been insufficient exploration to define a mineral resource. It is uncertain if further exploration will result in the target being delineated as a mineral resource.
The approximate grades and tonnages have been determined by taking the average underground inferred resource grade (5.48 g/t Au) plus or minus 30 percent and considering the cumulative strike extent of the four high grade shoots, average widths, and a 300 to 500 metre depth extension below existing resources.
Exploration Targets
Regional reverse circulation drilling completed in 2011 identified a number of significant intersections within iron formation units, separate and parallel to that hosting the Three Bluffs gold deposit. North Country believes there is excellent potential to identify additional resources from targets within 2 km of Three Bluffs.