Advanced exploration stage
Detour Fenelon Gold Trend
Nickel, copper, cobalt, platinum-group metals (PGM), and gold
|Current exploration activities:||
Review of project data for exploration targeting
Indicated resource of 4.75 Mt at 1.33% Ni, 0.15% Cu, 0.03% Co, 0.29 g/t Pt and 0.71 g/t Pd (March 2021)
The Grasset project is part of the 739 km2 Detour Fenelon Gold Trend land package acquired with the acquisition of Balmoral Resources Ltd. It is located adjacent to the Fenelon Gold and Jérémie properties (100% Wallbridge) and approximately 50 kilometres west-northwest of Matagami, Québec.
The Grasset nickel sulphide deposit occurs at the southern end of the Grasset Ultramafic Complex (“GUC”), immediately north of the regional Sunday Lake Deformation Zone (“SLDZ”). The deposit was discovered in 2012 and is comprised of two subparallel zones (H1 and H3 Zones) of disseminated to locally semi-massive sulphide mineralization. It is one of the largest nickel sulphide deposits in Canada’s Abitibi region, and the only North American nickel sulphide deposit with >50,000 contained tonnes of nickel and an average nickel grade of over 1.5% not controlled by a major mining company.
An initial resource estimate and preliminary metallurgical testing results were published in early 2016. Grasset is one of the largest nickel sulphide deposits in Canada’s Abitibi region. Drilling in 2018 and 2019 intersected another significant zone of nickel mineralization in the Central GUC zone, approximately 7 kilometres to the northwest.
Gold mineralization was also intersected on the Grasset project, both within the regional-scale SLDZ which transects the project and within secondary structures marginal to the GUC. Significant discoveries include the Grasset Gold Zone with an intercept of 1.6 g/t Au over 33.0 m, including 6.15 g/t Au over 4.04 m.
The last drilling program on the project was carried out by Balmoral in 2019 with geophysical surveys in early 2020. Since the acquisition of Balmoral, Wallbridge has not carried out exploration activities on the property. Drill targeting and budgeting is currently underway to develop an exploration programs for H2 2020.
Exploration on the Grasset project had been very limited prior to the acquisition of the property by Balmoral Resources Ltd. (“Balmoral”). The earliest reported mineral discovery is a quartz-vein hosted gold showing located on the southwestern shore of Lac Grasset where grab samples returned a high of 5.55 g/t Au. Four holes were drilled in the vicinity of this discovery in 1957 but no anomalous gold values were reported. All work during the late 1950’s and late 1970’s focused on drill testing of magnetic or conductive features in the search for VMS-type copper-zinc deposits, like the nearby Matagami and Selbaie mines.
In the late 1990’s, Fairstar Exploration tested two conductors on the northeastern portion of the property with one of these two holes intersecting a narrow quartz vein with strongly elevated silver values (209 g/t Ag over 0.30 m).
Work in 2006 by a previous operator identified nickel-copper-PGM mineralization at the northern end of the southern segment of the GUC.
Balmoral acquired the Grasset property in 2010. In 2011, they carried out a drilling program of 5 holes totaling 1,728 metres and discovered the Grasset Gold Zone with an intercept of 1.6 g/t Au over 33.0 m, including 6.15 g/t Au over 4.04 m, along the SLDZ. In 2012, they completed 7 holes totaling 1,899 metres and discovered a new nickel-copper-PGM system within the basal portion of a largely untested sequence of ultramafic rocks (GUC) on the property, the first of its kind recognized in the belt (~8.3 kilometres southeast of the occurrence identified in 2006 and 1 kilometre east of the Grasset Gold Zone). Discovery hole GR-12-09 intersected a 10 metre wide zone of disseminated pyrrhotite, pentlandite and minor chalcopyrite mineralization which returned an intercept of 0.51% Ni, 0.09% Cu, 0.15 g/t Pt and 0.33 g/t Pd over 9.17 m, including a high-grade interval of 1.34% Ni, 0.17% Cu, 0.16 g/t Pt and 0.54 g/t Pd over 0.4 m.
The winter 2014 program (11 holes totaling 3,634 metres) was successful in delineating at least three Ni-Cu-PGM mineralized horizons in the GUC and was consequently followed up with a 51-hole drill program totaling 16,673 metres. The bulk of the high-grade mineralization is in the upper of these three horizons (H3 Zone). The H3 Zone discovery hole GR-14-25 returned 45.28 m grading 1.78% Ni, 0.19% Cu, and 0.42 g/t Pt.
The 2015 drilling program (39 holes totaling 16,801 metres) continued to intersect broad zones of disseminated nickel-copper-PGM sulphide mineralization, extending the scale of the mineralized system and provided sufficient information to perform an initial resource estimate for the Ni-Cu-PGM Grasset deposit. In late 2015, Balmoral completed 12 exploration holes totaling 3,236 metres outside of the Grasset deposit.
An initial resource estimate and preliminary metallurgical testing results were published in March 2016 and all exploration activity ceased (prompted by low nickel prices) with the deposit remaining open to depth and along strike to the northwest.
Balmoral carried out a drilling program in 2018 and 2019 in the area 7 kilometres northwest of the Grasset nickel deposit within a high-level intrusive portion of the GUC (area referred to as the Central GUC area; prior drilling in 2015 by Balmoral with nickel mineralization identified in 2006). The drilling intersected both high grade and broader zones on nickel mineralization. The best high-grade intercepts included 7.58 m grading 1.05% Ni, 0.31% Cu, 0.05% Co, 0.20 g/t Pt and 0.48 g/t Pd (FAB-18-58). Broad zones of mineralization included: 112.85 m grading 0.27% Ni and 0.013% Co (beginning at <200 m below surface) (FAB-19-61) and 120.57 m grading 0.26% Ni and 0.012% Co (FAB-18-54).
The Grasset project covers approximately 20 kilometres of the SLDZ and to the east covers a portion of the Lower Detour Deformation Zone (“LDDZ”) as well. To the north of the SLDZ, mafic to felsic volcanic rocks dominate and are, at least in the western part of the property, intruded by a northwest trending, laterally extensive series of mafic to ultramafic intrusions. These intrusive rocks – collectively the Grasset Ultramafic Complex (GUC) - are known to host nickel-PGM mineralization which has been the focus of exploration on the Grasset project.
The GUC is formed by a stacked pile of basalts, gabbro and ultramafic sills and dykes, with minor rhyodacitic to dacitic volcaniclastics and rhyolite flows, and several narrow, intercalated bands of iron formation, and graphitic argillite in apparent conformable contact relations with the overlying rock units. The general attitude of the GUC is west-northwest, pinched between the Jérémie pluton and the Opatica Subprovince. Several zones of ductile deformation have been intercepted in drill holes along strike in the complex, suggesting that the NW-SE trend may correspond to a major fault, parallel to others similar faults north and south of the SLDZ. The southern portion of the complex is sheared and possibly folded by the SLDZ.
At the Grasset deposit, mineralization is concentrated in two stacked sulphide-bearing horizons (H1 and H3 Zones) oriented NW-SE within vertically dipping peridotite ultramafic units. Mineralization consists of metre-scale layers of net-textured, blebby semi-massive and massive sulphides. Pyrrhotite is the dominant sulphide mineral, with subordinate amounts of pentlandite, chalcopyrite and pyrite. The concentration of pentlandite and chalcopyrite is proportional to the total sulphide content. The two horizons are stacked, 25 to 50 metres thick, and separated by 10 to 80 metres of unmineralized ultramafic rock. The H3 Zone (a Type 2 komatiite hosted deposit) is defined over a strike length of roughly 500 metres to vertical depths of 550 vertical metres and hosts the bulk of the high Ni-Cu-PGE values defined to date. The less extensive H1 Zone (Type 1 komatiite-hosted) has been defined over a longer strike length (~900 metres) to a vertical depth of approximately 450 metres and hosts moderate nickel grades (<1%) over its entire extent. Both zones are open at depth.
In the Central Zone of the GUC, the broad zone of nickel sulphide mineralization occurs in a geological setting which is highly analogous to that of the high-grade Grasset deposit (7 kilometres to the southeast) and may represent the halo or marginal phase of a similar system. Like Grasset, the discovery occurs within an olivine cumulate dominated, intrusive conduit feeding higher level volcanic phases of the GUC. The high-grade nickel mineralization (Type 1 komatiite-hosted) occurs stratigraphically below this broader zone (Type 2 komatiite-hosted) within the lower volcanic sequence of the Complex. The new zone remains open along strike to the northwest, up-dip to the bedrock surface, and to depth.
In addition to the magmatic nickel potential of the GUC, Balmoral identified a number of gold zones on the Grasset property both within the regional-scale SLDZ which transects the property and within secondary structures marginal to the GUC.
The drilling by Balmoral from 2011 to 2014 outlined gold mineralization, named the Grasset Gold discovery, at the contact between the sequence of strongly deformed polylithic Timiskaming-type conglomerates and a mafic intrusive of the Manthet group, in the footwall of the SLDZ. The first hole intersected 1.66 g/t Au over 33.0 m, including two higher grade intervals grading 6.15 g/t Au over 4.0 m and 4.18 g/t Au over 5.0 m. The mineralization is hosted in an anastomosing quartz-carbonate vein system along the contact, which is open laterally and at depth.
At the Grasset nickel deposit, several styles of gold mineralization were intersected in the hanging wall and footwall to the GUC. A 21-metre wide zone of semi-massive pyrite and quartz veining returned an average grade of 0.66 g/t Au in a sheared zone located in the footwall. Elsewhere along the footwall of the GUC, 216 g/t Au over 0.78 m was intersected in the 1990s.
In addition, narrow horizons of semi-massive pyrite with anomalous zinc and copper values were identified in drill holes in a potential exhalative horizon at the contact between felsic and mafic rocks of the Grasset property.
In March 2016, Balmoral published an initial resource estimate for the Grasset nickel deposit, which was prepared by InnovExplo Inc. in Val d’Or, Québec. The Base Case estimate is focused on the higher-grade core of the deposit with 99% of the estimated resource contained within the high-grade core of the H3 Zone. Surrounding the high-grade core is a larger volume of disseminated nickel-sulphide mineralization which also remains open for expansion and which could potentially be brought into the resource model through changes in metal prices, exchange ratios, mining, milling, transport and smelting costs and improvements in the metallurgical assumptions contained within the initial resource model.
|CoG = 0.8% NiEq||Tonnes||NiEq
Additional notes on the MRE of the Grasset project
Wallbridge Mining Company Limited is an equal opportunity employer.
|Senior Underground Geologist||Full-Time||Fenelon|
|Geologist GIS Specialist||Full-Time||Fenelon|