Back River (Goose) Project

Click for more information



Mine TypeOpen Pit & Underground
  • Gold
Mining Method
  • Truck & Shovel / Loader
  • Cut & Fill
  • Drift & Fill
  • Longhole stoping
  • Longitudinal stoping
Backfill type ... Lock
Production Start... Lock
Mine Life... Lock
SnapshotThe Back River Gold District consists of five mineral claims blocks along an 80 km belt. The most advanced project in the district, Goose, is fully permitted, under construction, and has been de-risked with significant infrastructure currently in place. The Goose Project has an estimated two year construction period, which is expected to be completed in the first quarter of 2025.


B2Gold Corp. 100 % Indirect
On April 19, 2023, B2Gold Corp. completed the acquisition of Sabina, resulting in the Company acquiring Sabina’s 100% owned Back River Gold District located in Nunavut, Canada.



- subscription is required.

Deposit type

  • Vein / narrow vein
  • Banded iron formation hosted


Goose Site Geology The Goose Site includes the Llama, Llama Extension, Umwelt, Echo, Nuvuyak, and Goose Main deposits; it has a consistent stratigraphic model that can be applied to all deposits. The folded Beechey Lake turbiditic metasediments, including oxide and silicate banded iron formation (BIF) horizons have been broken down into a modelled stratigraphy consisting of, from oldest to youngest: the lower sediments that contain a subordinate interbedded deep iron formation (DIF); the lower iron formation (LIF); the middle mudstone, the upper iron formation (UIF); and the upper sediments. This sequence is cut by quartz-feldspar porphyry dykes (QFP) and later gabbroic dykes. Property Mineralization Gold mineralization on the Property is spatially correlated to iron formation stratigraphy, and as a result, the mineralization geometry is relatively continuous along the plunging antiform/synform structures; however, within the modelled mineralized zones, gold grades can be variable. Further details on the mineralization at the Property are provided in the subsections below. Llama and Llama Extension Deposits Gold mineralization is hosted in both iron formation and clastic sedimentary lithologies, as well as rarely within quartz veins in the QFP dykes. Late gabbro dykes are known to post-date the timing of gold mineralization and do not host economic concentrations of gold. Banded oxide-facies iron formation, consisting of chert + grunerite + magnetite, hosts most of the known gold mineralization. Silicate-facies iron formation consisting of actinolite + chert + grunerite, and locally interbedded clastic sediments hosts relatively lesser gold concentrations. Clastic sediments consisting of greywacke, siltstone, and mudstone are noted to be mineralized, but typically return low levels of gold, with locally elevated gold assays related to veining. In some cases, felsic dykes have been proven to host gold; however, to date the amount is considered relatively insignificant and associated with mineralized veining. Umwelt Deposit Similar to the Llama deposit, gold mineralization at the Umwelt deposit is focused within a structural corridor that is axial plane parallel. Gold mineralization is strongly associated with quartz veining and sulphidized iron formation lithologies, most commonly associated with arsenopyrite ± pyrrhotite ± pyrite. Pyrite and pyrrhotite are the most common sulphides in the Umwelt deposit, with pyrrhotite becoming significantly more prominent as the gold mineralized zone plunges to the southeast. Arsenopyrite is the most common sulphide associated with visible gold, occurring as fine- to coarse-grained, euhedral, individual masses of crystals, occasionally located preferentially along banding planes, trailing along fractures, as vein halos, or as clusters along vein margins. Pyrrhotite appears as two textures within the deeper portions of this deposit; in the first, pyrrhotite is fine-grained and appears to be locally replacing magnetite in zones of intense sulphidization; the second texture is coarsegrained, and more blebby in nature. This second texture is later than the magnetite-replacement pyrrhotite and clusters along fine fractures, within veins, and along vein margins. Gold-mineralized zones are characterized by sulphide and silica alteration including quartz flooding, accompanied by shearing and veining. Visible gold is locally present, especially when sulphides are greater than 10% and when coarse-grained arsenopyrite and pyrrhotite are present. Echo Deposit Gold mineralization at the Echo deposit is concentrated in, but is not limited to, the lower contact of the iron formation with interbedded sediments. Brittle deformation is prominent at the contact; there is also a moderate amount of shearing present locally. A poorly mineralized QFP intrudes proximal to the structurally influenced contact and is interpreted to be closely related to the timing of gold mineralization. Alteration consists of varying amounts of grunerite + chlorite + quartz + calcite ± biotite. Mineralization associated with higher gold values (up to 120 g/t Au) consists of pyrrhotite + pyrite + arsenopyrite occurring with quartz veining, as well as replacement of the host rocks. The overall sulphide content ranges from trace to 10% over 0.5 m. Nuvuyak Deposit Discovered in 2018, the Nuvuyak deposit is located approximately 850 m along strike and 1,000 m down plunge of the Goose Main deposit. The central antiform extends from the Goose Main deposit and continues through an area of intense D2 cross folding that had previously been drill tested, recovering encouraging mineralization. At the Nuvuyak deposit, the central QFP dyke continues to follow the axial-planar structural zone, and gold mineralization is predominantly hosted in polyphase-folded LIF stratigraphy. The tight- to isoclinal-antiform geometry is very similar to that of the Goose Main deposit. Gold mineralization consists of pyrrhotite mineralization within fractures, replacement zones in brecciated host rock, and veins with locally rich arsenopyrite zones and abundant visible gold. Sulphide mineralization is associated with quartz veining, shearing, and moderate to strong amphibole and chlorite alteration. Goose Main Deposit Most of the observed gold mineralization at the Goose Main deposit is associated with quartz veins, silicification, and shearing. Gold mineralization occurs within silicified and variably sulphidized iron formation and, to a lesser extent, mixed iron formation and meta-sedimentary units located in the underlying central greywacke, modelled as DIF. Observed sulphide minerals include pyrite, arsenopyrite, and pyrrhotite. Gold mineralization is associated with accessory chlorite, carbonate, hornblende, and grunerite. Visible gold is locally present, especially when sulphides are greater than 10% and when coarse-grained arsenopyrite is present. DEPOSIT TYPES The gold deposits at the Property are hosted by sulphidized oxide and silicate iron formation rocks, and clastic sediments that are cut by barren and sulphide-bearing quartz veins. Analogous deposits occurring in this region of the Arctic include the Lupin Mine approximately 225 km west of the Property (Bullis et al, 1994), the Meliadine district at Rankin Inlet (Carpenter et al., 2005), and the Meadowbank deposit north of Baker Lake (Sherlock et al., 2004). Within Canada, BIF-hosted gold deposits commonly occur within Archean-aged greenstone belts, typical of the shield areas of northern Ontario, Quebec, NWT, and Nunavut. Generally, BIF host rocks are thinly banded sedimentary rocks with alternating iron-rich and cherty (siliceous) layers. In BIF-hosted gold deposits, gold mineralization is commonly associated with quartz veining, shearing, and zones of hydrothermal alteration suphidizing the host silicate and oxide iron formations (mainly pyrite, pyrrhotite, and/or arsenopyrite). Gold mineralization is mainly located along shear zones associated with tightly folded and structurally complex BIF horizons that provide favourable chemical and structural traps. This understanding is being applied in the current exploration strategy for the Property.



- subscription is required.

Mining Methods


- subscription is required.


Crushers and Mills


- subscription is required.



- subscription is required.


CommodityUnitsAvg. AnnualLOM
All production numbers are expressed as payable metal.

Operational metrics

Daily processing rate  ....  Subscribe
Daily processing capacity  ....  Subscribe
Stripping / waste ratio  ....  Subscribe
Waste tonnes, LOM  ....  Subscribe
Ore tonnes mined, LOM  ....  Subscribe
Total tonnes mined, LOM  ....  Subscribe
Tonnes processed, LOM  ....  Subscribe
* According to 2021 study.

Production Costs

Cash costs Gold USD  ....  Subscribe
Total cash costs Gold USD  ....  Subscribe
All-in sustaining costs (AISC) Gold USD  ....  Subscribe
Assumed price Gold USD  ....  Subscribe
* According to 2021 study / presentation.

Operating Costs

OP mining costs ($/t mined) CAD 4.16 *  
UG mining costs ($/t mined) CAD  ....  Subscribe
Processing costs ($/t milled) CAD  ....  Subscribe
G&A ($/t milled) CAD  ....  Subscribe
Total operating costs ($/t milled) CAD  ....  Subscribe
* According to 2021 study.

Project Costs

MetricsUnitsLOM Total
Initial CapEx $M CAD  ......  Subscribe
Sustaining CapEx $M CAD  ......  Subscribe
Closure costs $M CAD  ......  Subscribe
Total CapEx $M CAD  ......  Subscribe
OP OpEx $M CAD  ......  Subscribe
UG OpEx $M CAD  ......  Subscribe
Processing OpEx $M CAD 693
Site services costs $M CAD 450
G&A costs $M CAD 415
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
Net Operating Income (LOM) $M CAD  ......  Subscribe
Pre-tax Cash Flow (LOM) $M CAD  ......  Subscribe
After-tax Cash Flow (LOM) $M CAD  ......  Subscribe
Pre-tax NPV @ 5% $M CAD  ......  Subscribe
After-tax NPV @ 5% $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 Aug 18, 2023
....................... Subscription required ....................... Subscription required Subscription required Aug 18, 2023
....................... Subscription required ....................... Subscription required Subscription required Aug 16, 2023
....................... Subscription required ....................... Subscription required Subscription required Aug 18, 2023

...... Subscription required 2021


- subscription is required.