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Canada

Sleeping Giant Mine

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Overview

Mine TypeUnderground
StageRestarting
Commodities
  • Gold
Mining Method
  • Shrinkage stoping
  • Room-and-pillar
  • Longhole stoping
Mine Life... Lock
SnapshotOver the 2023 year, the company will work on developing a budget plan for the resumption of production at the Sleeping Giant mine.

The cleaning and recovery phase having been completed; the team can now begin work to put the mill back into operation as quickly as possible.

In parallel with the start-up of the mill and the resulting sale of gold, Abcourt plans to begin development work in the upper levels of the Sleeping Giant mine with a view to extracting mineralized material.

Owners

SourceSource
CompanyInterestOwnership
Abcourt Mines Inc. 100 % Indirect
Abcourt is the sole owner of all leases and mining titles on the Sleeping Giant Property.

Contractors

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Deposit type

  • VMS

Summary:

Sleeping Giant is a sulphide-rich lode gold deposit of volcanogenic affinity. In a geochemistry study of the volcanogenic massive sulphide (VMS) deposits in the Abitibi belt, Gaboury and Pearson (2008) classified the Sleeping Giant Rhyolite as “F1 type”, which includes VMS deposits rich in gold and silver. Such deposits, which have the particularity of being spatially isolated, are probably the result of local hydrothermal processes (Gaboury, 2004). The Sleeping Giant deposit displays atypical characteristics of orogenic Archean deposits associated with major faults. According to Gaboury (1999), gold-bearing veins formed in subhorizontal strata shortly after QFP injections but before the end of mafic magmatism. All rock types, including gold-bearing veins, have been affected by regional ductile deformation (folding of strata and development of schistosity) and metamorphism to greenschist facies.

The mine sequence is represented by a volcano-sedimentary succession intruded by a felsic complex and transected by late hornblende-rich dykes. Strata strike predominantly E-W and dip steeply to the south, forming a single homoclinal stratigraphic succession. All the rock types have been metamorphosed to greenschist facies, but the prefix "meta" is omitted in the following sections to simplify the rock nomenclatures.

Mineralization styles
Gold-bearing veins
Gold-sulphide-quartz veins are generally massive and range from a few centimetres to 2 m thick (average of 50 cm for the mined veins). The veins are rich in gold with assays commonly > 100 g/t Au (unpublished data, Cambior Inc.). The vein contacts range from sharp, planar and free of surrounding planar fabric to undulose and schistose. Branching of main veins is a common phenomenon but does not show consistent attitudes. Veins terminate laterally through pinching out or arborescent multibranching veinlets.

Stratabound mineralization
Stratabound mineralization corresponds to gold-bearing segments of sedimentary horizons in which three main modes of occurrence have been observed: (1) subconcordant, millimetre- to centimetre-wide quartz-sulphide veinlets (the most common form); (2) concordant, parallel layers of massive sulphides; and, (3) disseminated sulphides, mainly pyrrhotite, pyrite and marcasite, with minor chalcopyrite and sphalerite. The sulphide layers are a few millimetres thick and are mainly composed of pyrrhotite and pyrite, with lesser chalcopyrite and sphalerite. In thin section, remnant magnetite grains and pseudomorphs suggest that the sulphide layers, and in part the disseminated sulphides, formed by the hydrothermal replacement of magnetite iron formations. Mineralization occurrences are related to both compositional (e.g., magnetite and silica contents) and rheological characteristics (e.g., bedding attributes and competency contrasts between individual beds) in the sedimentary horizons, and the relative proportions of which are variable. Some sulphide layers were mapped as the lateral termination of subconcordant quartz-sulphide veinlets. High-grade gold mineralization (>100 g/t Au) is restricted to the narrow quartzsulphide veinlets and sulphide layers.

SE-NW veinlet arrays
Arrays of gold-bearing veinlets occur in close spatial association with the gold-bearing veins hosted by mafic sills. These 1-cm to 4-cm-wide quartz-sulphide veinlets strike consistently SE-NW and dip steeply to the NE, parallel to the QFP dykes. Individual veinlets are planar and exhibit a regular distribution, with spacings of 1 to 2 m. The SE-NW veinlets generally have a consistent width, but some are boudinaged in vertical section. The grade of the veinlets ranges from 1 to 10 g/t Au.

Veining within the QFP dykes
This style of mineralization occurs solely within the QFP felsic dyke group, where it forms multiple, millimetre-wide quartz and sulphide veinlets and disseminated auriferous pyrite Crosscutting relationships indicate episodic veining injections within the dykes. Mineralization within the QFP dykes is a mine-scale phenomenon, but it is best developed in close spatial association with the gold-bearing veins. Systematic assays have revealed erratic gold grades ranging from nil to hundreds of g/t Au.

Gold mineralization with economic potential is mainly restricted to the volcanosedimentary succession bounding the dacitic intrusion. At the mine-scale, mineralized zones are scattered within a 1-km2 surface area. For the gold-bearing veins, there is a substantial difference in attitude and size depending on their position relative to the dacitic intrusion. North of the dacitic intrusion, the veins strike mainly E-W with a steep dip (> 75°) to the south. Their lateral extent ranges from 100 to 200 m with a vertical extent in excess of 700 m, yielding a ratio (lateral/vertical) of about 1:7.

Deformation affecting the host rocks is expressed by (1) the subvertical attitude of the volcanic strata; (2) the development of ductile planar and linear elements; (3) local mesoscopic folds; and (4) subhorizontal extensional calcite veinlets. These features are related to the regional deformation event. Subsequent deformation includes local shear zones and late brittle faults.

Reserves

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Mining Methods

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Comminution

Crushers and Mills

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Processing

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Production

CommodityProductUnitsAvg. AnnualLOM
Gold Metal in doré koz 30181
Gold Payable metal koz 181

Operational metrics

Metrics
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Waste tonnes, LOM  ....  Subscribe
Ore tonnes mined, LOM  ....  Subscribe
Tonnes processed, LOM  ....  Subscribe
* According to 2023 study.

Production Costs

CommodityUnitsAverage
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All-in sustaining costs (AISC) Gold USD  ....  Subscribe
Assumed price Gold USD  ....  Subscribe
* According to 2023 study / presentation.

Operating Costs

Currency2023
UG mining costs ($/t mined) CAD 226.24 *  
Processing costs ($/t milled) CAD  ....  Subscribe
G&A ($/t milled) CAD  ....  Subscribe
Total operating costs ($/t milled) CAD  ....  Subscribe
* According to 2023 study.

Project Costs

MetricsUnitsLOM Total
Pre-Production capital costs $M CAD  ......  Subscribe
Sustaining CapEx $M CAD  ......  Subscribe
Closure costs $M CAD  ......  Subscribe
Total CapEx $M CAD  ......  Subscribe
UG OpEx $M CAD  ......  Subscribe
Processing OpEx $M CAD 32.3
Refining and treatment costs $M CAD  ......  Subscribe
G&A costs $M CAD 11.6
Total OpEx $M CAD  ......  Subscribe
Income Taxes $M CAD  ......  Subscribe
Royalty payments $M CAD  ......  Subscribe
Gross revenue (LOM) $M CAD  ......  Subscribe
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After-tax Cash Flow (LOM) $M CAD  ......  Subscribe
Pre-tax NPV @ 5% $M CAD  ......  Subscribe
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Heavy Mobile Equipment

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Personnel

Mine Management

Job TitleNameEmailProfileRef. Date
....................... Subscription required ....................... Subscription required ........... Subscription required Subscription required Oct 2, 2023
....................... Subscription required ....................... Subscription required Subscription required Jun 7, 2023
....................... Subscription required ....................... Subscription required Subscription required Jun 7, 2023

EmployeesYear
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Aerial view:

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