McIlvenna Bay Project

Click for more information



Mine TypeUnderground
  • Copper
  • Zinc
  • Lead
  • Gold
  • Silver
Mining Method
  • Longhole stoping
  • Avoca
  • Transverse stoping
  • Sub-level stoping
Backfill type ... Lock
Mine Life... Lock
SnapshotMarch 16, 2022 - To date, Foran has completed work on the boxcut, ground support, as well as the blasting and excavation of the first 10m of planned advancement on the exploration decline. The construction and placement of the ore and waste pad is 95% complete and development of the containment pond is 40% complete. Foran has also re-energized the 1.2 MW existing distribution line and commissioned a temporary workshop that will support the ongoing exploration decline program.


Foran Mining Corp. 100 % Direct
Foran owns 100% of the McIlvenna Bay property.



- subscription is required.

Deposit type

  • VMS
  • Breccia pipe / Stockwork


McIlvenna Bay is a VMS deposit consisting of structurally modified stratiform volcanogenic polymetallic massive sulphide mineralization and associated stringer-style mineralization. The massive to semi-massive sulphides contain copper and/or zinc, with lower concentrations of silver, gold, and lead. The stringer-style mineralization generally contains elevated copper and gold. The deposit has undergone moderate to strong deformation and upper greenschist to possibly lower amphibolite facies metamorphism. The sulphide lenses are now attenuated down the plunge to the northwest.

The McIlvenna Bay Deposit includes five separate zones and two styles of mineralization that are mineralogically and texturally distinct and typical of VMS deposits.

• Massive to semi-massive sulphide mineralization in the Main Lens and Lens 3.
• Stockwork-style sulphide mineralization in CSZ directly beneath the Main Lens.
• Two other small lenses of stockwork-style mineralization:
- The Stringer Zone, which is located between the Main Lens and Lens 3.
- The Copper Stockwork Footwall Zone (FW), which occurs as a separate lens underneath the CSZ for approximately 150 m of strike length and could represent a fault offset and repetition of the Main Lens and CSZ.

The Main Lens at McIlvenna Bay is a large-massive to semi-massive sulphide horizon containing a metal zonation consisting of Cu- and Au-rich material near the upper plunge line of the deposit which. Down-dip it transitions into a more Zn and Ag dominant massive sulphide. In the 2013 resource estimate (Rennie 2013), the Main Lens was subdivided into the copper-rich Upper West Zone (UWZ) and the more zinc-rich Zone 2, based on these differences in mineralogy. However, statistical analysis of the assay grades within the lens suggests that there is a gradual transition between the two zones and that a hard boundary is not appropriate. The Main Lens Massive Sulphide is a continuous mineralized horizon which varies from 0.1 m to 18.0 m in thickness and averages 3.5 m overal.

The CSZ is a zone of stockwork style copper-rich mineralization that directly underlies and is in contact with the Massive Sulphide. The zone is wedge-shaped, running parallel to the plunge line Main Lens Massive Sulphide. Based on the limit of current drilling, the zone extends up-dip beyond the upper edge of the Massive Sulphide for approximately 100–200 m and terminates downdip where it pinches out against the Massive Sulphide approximately 100–200 m before the Main Lens ends. This unit is interpreted to represent the feeder zone to the massive sulphide system that was transposed into its current geometry during deformation. The CZS varies from 0.3 m to 26.0 m in thickness with an average thickness of 12.0 m.

The Main Lens Massive Sulphide and the underlying CSZ are generally in contact throughout the deposit, giving the bulk of the deposit an average thickness of 15.5 m overall. The mineralization in the deposit plunges at approximately -35° northwest from near-surface, for a down-plunge length of approximately 2,000 m.

Lens 3 is a massive sulphide that sits approximately 10 m to 30 m in the hanging wall above the Main Lens and could represent a stacked massive sulphide lens within the deposit. This lens has been traced intermittently along a strike length of 1,600 m and plunges parallel to the underlying Main Lens and CSZ. Lens 3 ranges in thickness from 0.1 m to 8.0 m and averages 2.0 m.

The Stringer Zone (SZ) comprises a narrow, intermittent lens of stringer-style sulphide mineralization that occurs sporadically between the massive sulphides of the Main Lens and Lens 3. The zone has a strike length of 850 m and averages 4.5 m in true thickness through the deposit.

The Copper Stockwork Footwall Zone (FW) is a separate lens that underlies the SZ and has been intersected in nine drill holes over approximately 150 m of strike length in the shallow, central part of the deposit. The lens varies in thickness from 0.3 to 38 m, with an average thickness of 30 m. The FW dominantly consists of stockwork style copper-rich mineralization similar to the CSZ, although, in several holes, narrow massive sulphide was also intersected at the top of the interval. It is possible that the FW represents a fault offset and repetition of the Main Lens and CSZ, but further drilling is required to prove the relationship of this lens to the rest of the deposit.

Massive to locally semi-massive sulphides are typical of the Main Lens and Lens 3 horizons in the deposit. The massive sulphide mineralization tends to be composed of 70% to 80% medium-sized and subrounded pyrite grains resembling “buckshot” in a fine-grained sphalerite-rich matrix. Sphalerite occurs as fine-grained and sometimes feathery minerals located in the interstices of the pyrite grains, ranging from 5% to 25% of the total unit. The sphalerite is generally dark brown to medium brown in color. Faint banding of the massive sulphides is occasionally apparent. Up to 10% fine-grained gray quartz, and occasionally fine calcite, are also observed in the interstices. Subangular to subrounded inclusions or fragments of massive black chlorite ranging from 2 mm to 50 mm in diameter comprise 10% of the unit. Patchy but commonly rounded chert fragments ranging from 1 cm to 3 cm in diameter can constitute up to 20% of the unit locally. Such chert, when present, is often surrounded by zones 1–3 cm in thickness that are enriched in pale brown sphalerite.

The semi-massive sulphides range from 20% to 60% sulphides which are found as veinlets, veins, and pods within strongly chlorite-altered rock. The sulphide portion tends to be either sphalerite or chalcopyrite dominant, with less than 20% fine-grained pyrite.

Sphalerite-dominant portions are generally comprised of reddish or pale brown to blonde sphalerite, indicative of zinc-rich and iron-poor sphalerite. Individual veins or pods have been documented to contain up to 56% zinc. Less common are the chalcopyrite-dominant intervals which are composed of 80% chalcopyrite over narrow widths. Veining and replacement textures are common in the semi-massive sulphides.

The CSZ mineralization is confined to the area below the Main Lens Massive Sulphide, but locally a similar stringer style of mineralization has also been observed between the Main Lens and Lens 3. In these instances, stringer-style mineralization can occur directly above the Main Lens Massive Sulphide, directly below Lens 3, or in the intervening stratigraphy between the two lenses, where it has been broken out as the “Stringer Zone” in the 2021 resource estimate (Lewis, San Martin and Jones 2021). The nature of the stockwork zone mineralization varies according to the host rock alteration, but, dominantly, this style of mineralization is associated with moderate to strong chlorite alteration. Chlorite-alteration hosted copper stockwork mineralization comprises chalcopyrite and pyrrhotite, with occasional pyrite, and is found in veinlets and pods cutting the chlorite. Sericite-quartz altered copper stockwork zones tend to be less prevalent and comprise exclusively chalcopyrite. The chalcopyrite lines fine, hairline fractures within the strongly silicified host, occurring in 5–10 cm long semi-massive pods containing angular to rounded host rock fragments. These pods and fractures appear to be late brittle features and may suggest that the chalcopyrite was remobilized into fractured rock, possibly during deformational events.

The sulphide mineralogy and the size of the alteration footprint suggest the presence of a proximal vent environment along the entire top plunge line of McIlvenna Bay, which is represented by the copper-rich portion of the Massive Sulphide.



- subscription is required.

Mining Methods


- subscription is required.


Crushers and Mills


- subscription is required.



- subscription is required.


CommodityProductUnitsAvg. Annual
Copper Metal in copper conc. M lbs 39
Zinc Metal in zinc concentrate M lbs 64
Gold Metal in concentrate koz 20
Silver Metal in copper conc. koz 486

Operational metrics

Daily mining rate  ....  Subscribe
Daily processing capacity  ....  Subscribe
Annual processing capacity  ....  Subscribe
Ore tonnes mined, LOM  ....  Subscribe
Tonnes processed, LOM  ....  Subscribe
* According to 2022 study.

Production Costs

All-in sustaining costs (AISC) Copper USD  ....  Subscribe
C1 cash costs Copper USD  ....  Subscribe
Assumed price Zinc USD  ....  Subscribe
Assumed price Copper USD  ....  Subscribe
Assumed price Silver USD  ....  Subscribe
Assumed price Gold USD  ....  Subscribe
* According to 2022 study / presentation.
** Net of By-Product.

Operating Costs

UG mining costs ($/t milled) CAD 41.3 *  
Processing costs ($/t milled) CAD  ....  Subscribe
G&A ($/t milled) CAD  ....  Subscribe
Total operating costs ($/t milled) CAD  ....  Subscribe
* According to 2022 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 615.9
Refining costs $M CAD  ......  Subscribe
Transportation (haulage) costs $M CAD 242.7
G&A costs $M CAD 174.2
Total OpEx $M CAD  ......  Subscribe
Total Taxes $M CAD  ......  Subscribe
Royalty payments $M CAD  ......  Subscribe
Gross revenue (LOM) $M CAD  ......  Subscribe
Net revenue (LOM) $M CAD  ......  Subscribe
EBITDA (LOM) $M CAD  ......  Subscribe
Pre-tax Cash Flow (LOM) $M CAD  ......  Subscribe
After-tax Cash Flow (LOM) $M CAD  ......  Subscribe
Pre-tax NPV @ 7% $M CAD  ......  Subscribe
After-tax NPV @ 7% $M CAD  ......  Subscribe
Pre-tax IRR, %  ......  Subscribe
After-tax IRR, %  ......  Subscribe
Pre-tax payback period, years  ......  Subscribe
After-tax payback period, years  ......  Subscribe

Heavy Mobile Equipment


- subscription is required.


Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Sep 5, 2023
....................... Subscription required ....................... Subscription required Subscription required Feb 28, 2022
....................... Subscription required ....................... Subscription required Subscription required Feb 28, 2022
....................... Subscription required ....................... Subscription required Subscription required Sep 5, 2023
....................... Subscription required ....................... Subscription required Subscription required Mar 1, 2023
....................... Subscription required ....................... Subscription required Subscription required Mar 27, 2023
....................... Subscription required ....................... Subscription required Subscription required Sep 5, 2023


- subscription is required.