Canada

Great Burnt Project

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Categories

Overview

Mine TypeOpen Pit & Underground
StagePreliminary Economic Assessment
Commodities
  • Copper
  • Gold
  • Copper Equivalent
Mining Method
  • Truck & Shovel / Loader
  • Cut & Fill
  • Sub-level Retreat
  • Drift & Fill
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Owners

SourceSource
CompanyInterestOwnership
Spruce Ridge Resources Ltd. 100 % Direct
Spruce Ridge Resources Ltd. owns 100% interest in the Great Burnt Property.

Contractors

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Deposit type

  • VMS

Summary:

Copper mineralization at the Great Burnt Copper Deposit occurs within metavolcanic-metasedimentary rocks that include reworked tuffs, volcaniclastics and clastic sediments associated with mafic volcanics that are interpreted to have formed in a back-arc basin. This type of sedimentary rock-dominated volcanogenic massive sulphide (“VMS”) mineralization has historically been classified as “Besshi-type” (Bond and Delaney, 2005), after the Besshi district of Japan. More recently, this type of mineralization has also been classified as mafic-siliciclastic or mafic-pelitic VMS (Galley et al., 2007).

Gold is a component of mineralization at the South Pond Deposit, the South Pond Gold Zones, and has been identified at the Great Burnt Copper Deposit itself. The South Pond Gold Zones occur within a strongly foliated area that has been termed the “South Pond Deformation Zone”. Whether the gold mineralization is syngenetic or epigenetic in origin remains to be determined.

MINERALIZATION
Four deposits of copper ± gold mineralization have been delineated on the Great Burnt Property: 1) Great Burnt Copper Deposit; 2) South Pond “A” Copper-Gold Zone; 3) South Pond “B” Gold Zone; and 4) End Zone Copper Prospect. The mineralization in each of these four deposits plus the Northern Zone, is described below. It is the Great Burnt Copper Deposit and the South Pond “A” Deposit that are subject to the Mineral Resource Estimates.

Great Burnt Copper Deposit
The Great Burnt Copper Deposit is a stratabound, tabular body of pyrrhotite-chalcopyrite mineralization within an interfingering mafic volcanic-metasedimentary contact (Bond and Delaney, 2005). The mineralization strikes approximately 10° to 20° and dips 65° to 80° to the southeast, with a 30° plunge to the south-southwest. The mineralization has a plunge length of approximately 600 m, pinches and swells from 2 m to 13 m in width along the plunge axis (McBride 1977), and has an average vertical extent of 120 m with a horizontal (plan) length of 210 m. P&E divided the Great Burnt Copper Deposit into three mineralized zones for the wireframe modelling of the drill hole database: the Main Zone, Lower Zone and North Stringer Zone.

Mineralization consists of disseminated to massive and banded, fine- to medium-grained pyrrhotite with coarse chalcopyrite, minor sphalerite and galena, and rare pyrite. Pyrrhotite is the dominant sulphide mineral present and occurs generally as massive layers, whereas chalcopyrite forms large blebs within the massive pyrrhotite and discrete layers of massive mineralization up to 6 cm thick. The main mineralized zone carries sulphide concentrations ranging from <40 to 90%. Zinc mineralization was reported by Celtic from drill hole GB-01-07, where assays of a 2.71 m zone of massive sulphide mineralization returned 1.33% Cu and 2.11% Zn (Bond and Delaney, 2005).

A stringer zone of mainly pyrrhotite-chalcopyrite occurs in the upper portions of the Deposit, which suggests proximity to hydrothermal discharge. Farther down-plunge, mineralization becomes more massive and contains pyrrhotite-chalcopyrite-sphalerite in discrete en-echelon lenses up to 14 m wide. The lenses have been interpreted to be primary deposits or a boudinaged and (or) folded and transposed horizon (McBride, 1979; Bond and Delaney, 2005).

The mineralization is hosted by interbedded mafic volcanics and metasedimentary rocks composed of dark green, fine-grained chloritic and actinolitic mafic volcanic tuffs and minor lapilli tuffs interfingered, and in gradational contact with, fine-grained, massive amphibolitic to well-banded biotitic to locally graphitic greywacke and siltstone (McBride, 1979). McBride (1977) noted that mafic volcanics near higher concentrations of sulphides are typically greyish and more siliceous with or without sericite.

The contact between sulphide mineralization and wall rock varies from sharp to gradational with disseminated mineralization. Colman-Sadd and Swinden (1982) interpreted the eastern contact to be the stratigraphic footwall, with 30 to 40 m of the footwall being weakly altered to black chlorite and, locally, quartz with associated stringers of pyrite, pyrrhotite and chalcopyrite. The hanging wall to the west shows little evidence of alteration or mineralized contact between massive sulphide and barren rock. Wallis (2000) described the immediate footwall and hanging wall contacts as sharp with little visible alteration and suggested that the sulphide mineralization had been detached from the footwall stringer zone (found at the North Stringer Zone) during D1 deformation.

North Stringer Zone
The North Stringer Zone is located approximately 200 m northeast of the Great Burnt Copper Deposit. The North Stringer Zone consists of weakly altered and mineralized rocks that have been delineated along a strike-length of 335 m and to a vertical depth of 50 m in 20 EX diamond drill holes. The surface expression of this Zone is characterized by a moderate strength VLF-EM anomaly over a strike length of 400 m with a coincident high magnetic anomaly over 300 m (Collins, 1996).

South Pond “A” Copper-Gold Deposit
The South Pond “A” Deposit (also known as the South Pond Copper-Gold Deposit) is located 10 km north of the Great Burnt Copper Deposit and 3 km southwest of South Pond. The mineralization occurs at a similar stratigraphic level and within similar lithologies to the Great Burnt Copper Deposit. The South Pond “A” Deposit has a 914 m north-easterly strike-length and dips 60° to the west. This deposit has been delineated in approximately 30 drill holes to a maximum vertical depth of 152 m, is up to 15 m wide (Collins, 1995a), and discordant to bedding and foliation (Swinden, 1988; Desnoyers, 1991).

Mineralization in the South Pond “A” Deposit consists of disseminated to semi-massive pyrrhotite (up to 40%) with 1 to 2% disseminated blebs of chalcopyrite, minor pyrite and rare local arsenopyrite in variably silicified, sheared and locally brecciated mafic volcanic flows and tuffs. Host rocks of the Deposit consist of pillow lava, mafic tuff and fine to medium grained clastic sedimentary rocks in the form of hornblende-albite-biotite-epidote schist and hornfels interbedded with graphitic schist, cherts, quartzite and lesser mica schist and phyllite (Larsen, 1969). The rocks are moderately chloritized with pervasive carbonate alteration in the form of concordant calcite veinlets or fine-grained disseminations (Desnoyers, 1987). The boundaries of the Deposit are gradational and reflect a decrease in total sulphide content and chalcopyrite.

South Pond “B” Gold Zone
The South Pond “B” Zone Gold Zone (also known as South Pond Gold Zone) is an advanced exploration target located one km south of the South Pond “A” Copper-Gold Deposit, has been delineated by approximately 4,200 m of BP drilling from 1987 to 1989. The drilling defines the Zone over approximately 1,400 m in a north-south direction. The Zone is located approximately 600 m south of the South Pond Copper-Gold Deposit and occupies a similar stratigraphic horizon, such that the combined zones occur over 2.0 km of strike length of near surface gold-copper mineralization.

End Zone Prospect
The End Zone Prospect is a geochemical, gravity, magnetic and EM anomaly located to the south of South Pond Gold Zone and six km north of the Great Burnt Main Zone. Historical samples from mineralized boulders in the End Zone area returned assays of up to 13% Cu and 2.5% Zn. The bedrock source of the boulders remains to be determined.

Reserves

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Mining Methods

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Comminution

Crushers and Mills

Milling equipment has not been reported.

Processing

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Production

CommodityProductUnitsLOM
Copper Concentrate kt 87
Gold Payable metal oz 1,340

Operational metrics

Metrics
Daily ore mining rate  ....  Subscribe
Daily milling rate  ....  Subscribe
Annual ore mining rate  ....  Subscribe
Waste tonnes, LOM  ....  Subscribe
Ore tonnes mined, LOM  ....  Subscribe
* According to 2022 study.

Production Costs

CommodityUnitsAverage
Cash costs Copper USD  ....  Subscribe
All-in sustaining costs (AISC) Copper USD  ....  Subscribe
Assumed price Copper USD  ....  Subscribe
Assumed price Gold USD  ....  Subscribe
* According to 2022 study / presentation.
** Net of By-Product.

Operating Costs

Currency2022
Processing costs ($/t milled) CAD 25 *  
G&A ($/t milled) CAD  ....  Subscribe
Total operating costs ($/t milled) CAD  ....  Subscribe
* According to 2022 study.

Project Costs

MetricsUnitsLOM Total
Sustaining CapEx $M CAD  ......  Subscribe
Closure costs $M CAD  ......  Subscribe
Processing OpEx $M CAD 26.7
G&A costs $M CAD 6.3
Total OpEx $M CAD  ......  Subscribe
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Net revenue (LOM) $M CAD  ......  Subscribe
After-tax Cash Flow (LOM) $M CAD  ......  Subscribe
After-tax NPV @ 5% $M CAD  ......  Subscribe
After-tax NPV @ 10% $M CAD  ......  Subscribe
After-tax NPV @ 8% $M CAD  ......  Subscribe
After-tax IRR, % $M CAD  ......  Subscribe
After-tax payback period, years  ......  Subscribe

Heavy Mobile Equipment

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Personnel

Mine Management

Job TitleNamePhoneEmailRef. Date
....................... Subscription required ....................... Subscription required ........... Subscription required ........... Subscription required Aug 17, 2023

EmployeesYear
...... Subscription required 2022

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