Cheechoo project

The Cheechoo gold project is located in the Eeyou Istchee James Bay region of Quebec, less than 15 km from Newmont’s Éléonore gold mine. The latest resource estimation update conducted on the property (Oct. 2020) has resulted in inferred resources containing 2.0 million ounces of gold (Moz), from 93.0 million tonnes (Mt) at an average grade of 0.65 grams of gold per tonne (g/t Au), with a significant upside for expanding these resources.


The Cheechoo Property.

The Cheechoo gold project is located in the Eeyou Istchee James Bay region of Quebec, less than 15 km from Newmont’s Éléonore gold mine, which began its production in 2015.

The property consists of a main block of 121 claims as well as a secondary block of 35 claims located about 20 km to the west. These 156 claims totaling 81 km2, are fully owned by Sirios (with a royalty to Golden Valley Mines Ltd. ranging from 2.5% to 4% based on gold price on 145 claims).

The Cheechoo project is located approximately 800 km north of Montreal and 200 km east of the Wemindji Cree community.



Regional Geology of the Cheechoo Project.

The property straddles the suture zone between the Opinaca meta-sedimentary subprovince and the La Grande volcano-plutonic province. It is composed of both granitoids typical of the La Grande sub-province and metatexites typical of the Opinaca sub-province. The geology of the property consists of tonalite, meta-wacke, paragneiss, granite and pegmatite.

The gold mineralization is primarily hosted in a silicified and albite rich tonalite, with the presence of parallel or stockwork-type centimetric quartz veins or veinlets. It includes a very low sulfide content (<1%, pyrrhotite-arsenopyrite-pyrite) along with variable amounts of amphibole, biotite, chlorite, diopside, tourmaline and scheelite. Most of the gold occurs as free coarse grains. These overall characteristics are typical of Reduced Intrusion Related Gold Systems.

For more information, please consult the scientific article published by the Geological Survey of Canada in 2018 on the Cheechoo property.


Resource estimation

The resource estimation update conducted on the property (Oct. 2020), based on an open-pit constrained model, resulted in:

  • Inferred resources containing 1,955,000 ounces of gold, from 93.0 million tonnes (Mt) at an average grade of 0.65 grams of gold per tonne (g/t Au);
  • Significant upside for expanding the mineral resources with the potential to add a significant amount of additional gold ounces that have been outlined on the Cheechoo property but require an agreement with the neighbouring property to access this material.

This data comes from the resource estimate update (BBA Inc., Pierre-Luc Richard, geo.) which results have been published in the November 17, 2020 press release.


Completed exploration work

As of April 2020, the exploration work conducted on Cheechoo amounts to 68,000 m of drilling (295 holes) and 3,200 m of channel sampling. (For more details, please consult the press release list announcing the drilling results.)

The main gold area (approximately 500 by 500 m) has been drilled with a 50 m spacing. In order to collect structural data, downhole logging surveys were completed on 57 drill holes.

The following work has also been conducted on the property:

  • Ground magnetometer and induced polarization surveys (2012);
  • Helicopter-borne magnetometer surveys (2014, 2017);
  • Soil (humus) and till sampling surveys (2010, 2015-2017).


Gold mineralization

The Cheechoo gold project’s mineralized areas.

Low-Grade Envelope

The work undertaken to date demonstrates the extent of the Cheechoo mineralized system. The mineralization spreads for more than 1,400 m along the tonalite/meta-sediments contact. (ref. February 8, 2018 press release) and up to 500 m towards the interior of the intrusion. Gold mineralization has also been tested down to 650 m below the surface.

Furthermore, the exploration work carried out to the west of the main area indicates that the mineralized envelope could extend to the west towards the area called Eclipse.

High-grade Zones

High-grade gold intervals are frequently intersected within the low-grade envelope. As of January 2020, a total of 37 high-grade zones have been defined and modelled, including the Jordi Zone, which is distinguishable by the presence of gold bearing pegmatite and quartz-feldspar veins with visible gold. This zone, which is 5 to 10 m thick, is continuous for more than 300 m laterally and for nearly 200 m downdip, while remaining open at depth. About 50 drill holes have intersected it, with grades up to 56.4 g/t Au over 8.2 m.

Mineralization at Depth

Intervals of medium to high-grade gold were intersected at depth in the tonalite including, for example, drill hole #82E (2.0 g/t Au over 16.0 m, including 7.4 g/t Au over 3.1 m) at a depth of more than 600 m and drill hole #98 (17.4 g/t Au over 3.0 m, including 159.3 g/t Au over 1.0 m) at a depth of more than 400 m.

Gold mineralization was also observed in meta-sedimentary rocks in deeper drill holes such as drill hole #98 (1.7 g/t Au over 34.9 m, including 4.4 g/t Au over 8 m) at a vertical depth of 505 m and drill hole #82E (1.1 g/t Au over 24 m, including 4.6 g/t Au over 2.5 m) at a vertical depth of 491 m (ref. May 30, 2017 press release).

Eclipse Area

The Eclipse area is located at more than 750 m west of the main area and represents the continuity of the Moni showing (from the neighboring Éléonore South property). This area’s mineralization is characterized by near-surface, very high-grade gold veins, which are hosted in a low-grade tonalite.

These veins have been intersected by multiple drill holes, including drill hole #95 (11.9 g/t Au over 13.5 m, including a quartz vein with visible gold assaying 65.1 g/t Au over 2.1 m) and drill hole #99 (11.2 g/t Au over 10.6 m, including two intervals with visible gold assaying 63.3 g/t Au over 1.0 m and 50.5 g/t Au over 1.0 m).

Other exploration targets

North-West Area. 1.5 km north-west of the main area, many gold mineralized intervals were intersected by drill holes #47 (5.5 g/t Au over 1.0 m and 5.3 g/t Au over 1.1 m), #48 (1.6 g/t Au over 8.3 m), #63 (3.4 g/t Au over 1.1 m) and #64 (1.9 g/t Au over 3.3 m).

Till Area. 3 km north-west of the main area, gold anomalies have been detected in till samples. In this area, drill hole #73 intersected anomalous gold grades, including 0.8 g/t Au over 5.4 m.


Metallurgical tests

2019 Metallurgical Tests Results.

Metallurgical tests conducted in 2019 on samples representative of Cheechoo’s mineralization obtained gold recovery rates up to 97%, including 88% by gravimetric process.

The tests also demonstrated potential to concentrate the sulfides in the gravity process tailings using flotation. Note that the tailings from the treatment of Cheechoo samples have a very low sulfides content, in the order of less than 0.2%. Cyanidation tests also show a low consumption of reagents (<0.6 kg/t of NaCN and <1.1 kg/t of Ca(OH)2).

For more details, please consult the September 2, 2019 press release.


Positive characteristics

The Cheechoo project has numerous positive characteristics, including:

  • A strong exploration potential;
  • Excellent gold recovery (up to 97% of recovered gold, including 88% by gravity);
  • A low strip ratio of 1.1;
  • Proximity to existing infrastructures, including :
    • Road access;
    • An airfield;
    • A hydro-electric power line;
    • The Éléonore mine camp;
    • 3G / LTE Network.

Drill holes

Drill holes 1 to 4

Drill holes 5 to 8

Drill holes 9 to 12

Drill holes 13, 14

Drill holes 15 to 17

Drill hole 18

Drill hole 19

Drill holes 20, 21

Drill holes 23, 25, 26, 30

Drill holes 22, 24, 27 to 29

Drill holes 22ext and 31 to 56

Drill holes 25ext and 57 to 59

Drill holes 52ext and 60 to 83

Drill holes 84 to 90

Drill holes 91 to 93

Drill holes 37E, 82E, 94, 98, 100

Drill holes 58E, 95

Drill holes 95 to 99

Drill holes 36E and 101 to 107

Drill holes 108 to 111

Drill hole 112

Drill holes 113, 115 to 119

Drill holes 120 to 125

Drill holes 126 to 140

Drill holes 141 to 150

Drill holes 125E and 20E

Drill holes 152, 153, 155 to 158, 160

Drill holes 161, 163, 166, 168

Drille holes 164, 167, 169 to 179

Drill holes 151, 154, 159, 162, 165, 181, 182, 184, 185, 192 to 194

Drill holes 183, 186 to 191

Drill holes 190, 196 et 33E

Drill holes 199 to 204

Drill holes 205 to 220, 222, 223, 227, 229 to 234

Drill holes 221, 235, 239, 240, 243, 245

Drill holes 224 to 226, 228, 236 to 238, 241, 242, 244

Drill holes 246, 248, 249, 251, 253, 254

Drill holes 247, 250, 252, 255 to 267

Drill holes RC-01, RC-02, 268, 269, 271 to 274

Drill holes 279, 280, 286, 288 to 290

Drill holes 291 to 296


Maps and sections

Drill holes map 2017

Channels map

Close-up of channels

Trench 2-2

Trench Mafic Dyke

Main Stripped Area

Map 108-111

Sections 108

Sections 109-110-111

Map 112

Section 112

Map 120-125

Sections 120-124-125

Sections 123

Map 127-140

Sections 128-136-138-139

Sections 131-132

Section 140

Map 141-150

Section 142

Section 146-149

Map 20E and 125E

Map 152,153,155-158,160

Assay map up to #160

Map 161, 163, 166, 168

Section Eclipse

Map 164, 169, 172-177, 179

Map 183, 186-191

Section 186, 188, 191

Section 183

Section 189

Map 151, 154, 159, 162, 165, 181, 182, 184, 185, 192-194

3D Model with grade above 1 g/t Au

Map 190, 196, 33E

Section 190, 196

Section 33E

Map 199-204

Section 199-204

Map 205-220, 222, 223, 227, 229-234

Eclipse Longitudinal

Map 221, 235, 239, 240, 243, 245

Section 239

Section 240

Section 245

Map 224-226, 228, 236, 238, 244

Eclipse Longitudinal June 2019

Discovering gold from prospecting to advanced exploration.
Sirios generates and manages its mining exploration projects by working closely with its partners, fully respecting communities and the environment, as well as utilizing the latest advanced technologies.