Metals of Interest
Gold, Silver, Copper, Zinc
Size and Location
The Troilus Property is located in the central part of Quebec in NTS map sheets 32J09, 32J10, 32J15 and 32J16 and consists of 286 claim totalling 15,512.20 hectares. The Troilus Group Property is composed of three principal claim blocks and a few scattered claims located approximately 120 kilometres north-northwest of the town of Chibougamau and 250 kilometres northeast of the town of Lebel-sur-Quévillon, Eeyou-Istchee James-Bay territory.
The Property is composed of 286 Map Designated Claims totalling 15,512.20 hectares. Three principal blocks form the property and are divided as follows:
Bullseye Block consists of 124 claims totalling 6,724.10 hectares and is centrally located within the Frotet greenstone belt.
Larabel Block consists of 77 claims totalling 4,164.0 hectares and is located in the northeastern portion of the greenstone belt.
Troilus Base Metals Block consists of 85 claims totalling 4,624.10 hectares.
Access and Infrastructure
The property is easily accessible by an all weather road from the town of Chibougamau and a network of gravel roads gives access to different portions of the claim group. A powerline passes near the Property and several camps are located in the area, including the installations of Troilus Gold which is working on the past producing Troilus gold mine.
Since 1957, a broad range of exploration work were performed on the Frotet-Troilus belt. Those historical work were recently listed and resumed in Ilieva et al. (2014) and in Auger and Brousseau (2018). This very last report consists in a compilation of all work and results done until March 2018 on the former property of Beaufield Resources Inc., today owned by Osisko Mining Corp. Most of the following statements are thus extracted of the compilation report from Auger and Brousseau (2018) and references herein.
In 1957, it was the discovery of a Cu-Ni rich bolder in the region which led to an intensive staking of the Frotet-Troilus greenstone belt. From this to late 1950s, ground and airborne magnetic/EM survey as well as field exploration were undertaken mostly for gold and copper-gold potential. Nonetheless, during early 1960s, several base metals and/or gold occurrences were found (Figure 4) while drilling for the MAG/EM anomalies revealed by late 1950s surveys. These discoveries include showings Baie Moléon (181 000 t @ 1.56% Cu, 3.4% Zn), Diléo (0.50 m @ 3.70% Cu, 6.20% Zn) and Lac Coulombe (4.90 m @ 1.00% Cu, 2.19% Zn) (Dessureault, 1998; Ilieva et al., 2014).
First sub-economic potential of the region waited for 1970 with Lessard mineralization exposure. It was followed by various exploration strategies in the 1970s by SELCO Mining Corporation Limited, SDBJ, Shell Canada Limited, Muscocho EXPLS Limited and the Québec Government. The 2 000 000 Oz gold plus 70 000 tons copper Troilus deposit and so-named mine was discovered in 1987 after almost 4 000 m drilling campaign this year.
Late 1980s and early 1990s exploration works led to the highlighting of several gold rich volcanogenic occurrences, including the Inco VMS Boulder (3.0% Cu, 2.7% Zn, 8.0 g/t Au) and showing. Tortigny polymetallic mineralization (Not NI 43-101 compliant 490 000 tons @ 2.21% Cu, 6.15% Zn, 61.1 g/t Ag, 0.24% Pb) was found by Noranda in 1994. Troilus Mine construction started in 1996. The same year, SOQUEM Inc. crosscut the De Maurès evidence (9.10 m @ 1.3% Cu, 10.0% Zn, 24.0 g/t Ag).
From late 1990s to 2008, Falconbridge et SOQUEM Inc. were the two most active companies on the whole area and conducted a range of exploration surveys (from ground field work, to soil sampling and airborne geophysics). About 30 to 40 holes were drilled based on these exploration technics. Knowledge as well as best intersections on the 1960s showings were thus updated. From Mid-2000s to 2012, Beaufield Resources performed various work and drilling campaigns notably on the Tortigny evidence. In 2015, First Quantum Minerals Limited realized flown gradiometric and VTEM surveys over Troilus Mine.
The area of study belongs to the Superior Province. A synthesis on the Superior Province by Card (1990) and Hocq (1994) has divided the Superior Province in 20 sub-provinces based on lithologies, metamorphism, structures, geochronology and geophysical data. Troilus Property is part of the Opatica Sub-Province, which is an Archean volcano-plutonic assemblage. It extends in the southto the limit with the Abitibi greenstone belt, and in the northuntil the limit of migmatized paragneiss, which constitute the most part of the Opinaca Sub-Province.
The Frotet-Evans greenstone belt belongs to the Opatica Sub-Province (Figure 3). It extends for about 250 km from Lac Mistassini to the Nottaway River. It is composed of two Archean volcanic piles separated by a sedimentary basin. Both volcanic piles consist of thick accumulations of submarine basalt and andesite interbedded with minor amounts of rhyolite, intermediate to felsic volcanoclastic rocks, siltstone, argillite and greywacke. The belt is 45 km wide and is divided in four segments: 1) Evans-Ouagama, 2) Storm-Evans, 3) Assinica and 4) Frotet-Troilus
Based on the compilation works held by many authors in the sector (Gosselin, 1995, 1996; Beauregard and Gaudreault, 2005; Stephens and Rivard, 2013; Auger and Brousseau, 2018), the Frotet-Troilus greenstone belt is usually divided into four structural and lithostratigraphic domains or volcanic cycles (cycles I to IV) that are separated by major regional faults and bounded on every sides by granodioritic to tonalitic intrusions.
The Dompierre formation was firstly defined by Simard (1987) as ferrous tholeiites. They mostly are composed of pillowed to massive basalts with more local gabbros as decametric to hectometric sills. Dompierre Formation belongs to cycle I. The higher iron content found within those basalts, compared to the other formations of cycle I, indicates a more evolved magma (Gosselin, 1996). Rare volcanogenic mineralization is found associated to thin pyroclastic or sedimentary units which are interbedded in the volcanic pile. Dompierre Formation is older than Frotet Formation.
The Frotet Formation is composed of variable pyroclastics rocks and sediments. It belongs to volcanic cycle II. Calc-alkaline blocky tuffs are the most represented facies. In the area of interest, the blocks are composed of a porphyritic felsic rock and of calc-alkaline amygdoïdal andesites that can be attributed to cycle I De Maurès Formation (Gosselin, 1996). These pyroclastic units are locally injected by ultramafic to mafic hectometric sills.
This formation belongs to cycle III. It is the only transitional unit within the Frotet-Troilus assemblage. Because of this geochemical signature, it represents an important regional stratigraphic interval. Châtillon Formation is composed of variolitic and pillowed basalts. Several members are recognized within this formation. Corchet Member contains komatiitic micro-spinifex basalts. Testard Member hosts the most part of the tuffs and graphitic argillite levels in the Châtillon Formation (Simard, 1987). The most important VMS showing (Tortigny) of cycle III is associated to this formation and to these thinly bedded sediments horizons.
Domergue Nord Formation
Domergue Nord Formation (Simard, 1987) is part of cycle IV. It is composed of magnesian basalts, that are massive to pillowed. Magmatic affinity is clearly tholeiitic. Basalts are interbedded with gabbroic sills. Decametric horizons of sedimentary and pyroclastic rocks are commonly found in the basalts. These pyroclastic units are more concentrated at the bottom of Domergue Formation, which may indicate a gradual contact from the top of Frotet Formation (Gosselin, 1996).
Several mineralization genetic models are found in the Frotet-Troilus greenstone belt. Some are clearly polymetallic thought only gold or copper evidences are also present. These geological and metallogenic contexts give to the Troilus property potential for copper, zinc, silver and gold occurrences.
Volcanogenic Massive Sulfides
VMS are Cu-Zn±Au±Ag±Pb deposits that are the most represented mineralization type of the Frotet-Troilus Belt. They form on or within the volcanic seafloor in association with discharge fault zone of subseafloor convecting hydrothermal cell (Franklin et al., 2005). Mineralization consist both in stratabound massive sulfide lenses and in discordant zoned alteration and stockworks.
Close to the property, Tortigny deposit is one good example of VMS mineralization. Lenses occur in pellitic meta-sediments at a very specific locus which is a tholeiitic-transitional mafic volcanism interface. Measured and indicated resources are 1 098 000 tons at 1.78% Cu, 3.65% Zn, 48.51 g/t Ag and 0.35 g/t Au (Ilieva et al., 2014). These resources are contained in discontinuous semi-massive to massive zoned sulfides lenses as well as in larger lateral extent disseminated horizons. Some other VMS type occurrences are Lac Coulombe, Baie Moléon, Lessard, Diléo, Inco and Jacobus.
Archean Cu-Au porphyry
Copper-Gold porphyry has an economic potential for the whole area, since the only former mine – Troilus - of the Frotet-Troilus belongs to this genetic model. Troilus Mine has produced more than two million ounces of gold (2 M. Oz. Au) and almost 70 000 tons copper over thirteen years (1997-2010). Porphyry deposit is still a matter of interest when this rapport is written, as Troilus Gold Corporation is to accomplish a 30 000 m definition drilling in the coming years (Troilus Gold, 2018a). The most recent press release of Troilus Gold states 121.7 Mt @ 0.87 g/t Au and 0.086 % Cu as indicated resources and 36.1 Mt @ 0.88 g/t Au and 0.083 % Cu as inferred resources (Troilus Gold, 2018b).
Copper-Gold porphyry are hydrothermal deposit that form at depth of about 4 km in subduction related magmatism setting. During fractionation, initially volatile rich calc-alkaline magma gets oversaturated in volatiles and frees a hydrothermal fluid. Such fluid is responsible for the formation of stockworks, large zoned alteration halos rich in copper (± gold) sulfide disseminations (Sinclair, 2007). At Troilus Mine, chalcopyrite, pyrite and pyrrhotite disseminated mineralization is hosted in quartz-chlorite breccias and vein swarms. These ore shoots are mostly contained at Troilus Diorite margins and in associated porphyritic felsic dykes (Zones Z87 and J4, Troilus Gold, 2018c).
Ni-Cu sulfides are magmatic deposits that form in association with syn-volcanic ultramafic flows or mafic to ultramafic intrusions. Sulfur saturation in the magma is responsible for sulfide precipitation and accumulation, and can be caused by various processes, crustal sulfur contamination from surrounding sediments being one (Eckstrand and Hulbert, 2007). Such mineralization has long been known in the Frotet-Evans belt, since the discovery of a Cu-Ni rich boulder in 1957 (Auger and Brousseau, 2018). The main Ni-Cu sulfide showing in the belt is the Horden occurrence, which take places at the contact between metasediments and the mafic-ultramafic Chabouillé intrusion, 200 km westfrom Troilus property. Mineralization consists in pyrrhotite, chalcopyrite, pentlandite, pyrite and rarer sphalerite. Another good example of this genetic model is The Lac Rocher, but both this showing and Horden are far away from the Troilus property. The only Ni-Cu evidence in the Troilus belt is the Boulder Groupe showing found in 1957 in which no outcrop nor economic potential has ever been highlighted (SIGÉOM, 2018).
Li-Cs-Ta (LCT) pegmatites are also found on the property, such as, Moblan and Moléon-Lithium. Mineralization consist in spodumene crystals in large (decametric) pegmatites intrusions. Volatile rich granitic magmas fractionate to an undercooling point where only hydrated and light element rich minerals remain and grow (London, 2008). This type of mineralization can be substantial sources of lithium as well as some other rare metals. Moblan is owned 60% by Lithium Guo Ao Limited and 40% by SOQUEM Inc (SIGÉOM, 2018). Perilya Limited’s press release in 2011 states 14.25 Mt at 1.41% Li2O (Perilya, 2011). The main showing is a major 40 m large pegmatite dykes east-weston 700 m and dipping 35 degreesnorth. It takes place in the hinge of Frotet Anticline.