The Kwanika porphyry deposits are located along the western margin of the Quesnel Terrane, a Late Paleozoic to Early Jurassic island arc that hosts numerous calc-alkalic to alkalic Cu-Au porphyry deposits including the Copper Mountain, Mount Milligan and New Afton Cu-Au mines, the giant Highland Valley Cu-Mo mine, and NorthWest’s Lorraine – Top Cat Cu-Au-Ag±PGE porphyry project. Kwanika geology is dominated by Jurassic intrusions that are part of the Hogem batholith, to which Kwanika mineralization is related, emplaced into favourable Triassic Takla Group volcanic rocks. The Kwanika hydrothermal system and the Hogem intrusions are truncated on their west side by the Pinchi fault, a regional-scale dextral strike-slip structure. Mineral resources at Kwanika are hosted by the Central Zone, and the South Zone located just 1.5 km to the southeast.
Kwanika Central Zone. Mineralization in the Central Zone is hosted by Early Jurassic monzodiorite porphyry to diorite intrusions emplaced into Triassic-aged Takla Group volcanic rocks, which are cut by late-mineral diorite porphyry dykes. The deposit has a structurally controlled core of very high-grade Cu-Au-Ag mineralization characterized by disseminated and vein-hosted chalcopyrite ± bornite within intense K-feldspar alteration related to abundant quartz-sulphide veins (Table 1., Figure 3 & 4). High-grade Cu-Au-Ag mineralization begins at top of bedrock in an open pit resource that extends continuously to depth to the west where block cave mining may be feasible. An extensive zone of Cu-Au-Ag mineralization of more moderate grade occurs in diorite intrusions and Takla Group volcanic rocks that surround the high-grade core. The western part of the Central Zone is overlain nonconformably by Cretaceous-aged sedimentary rocks, which preserved a small tonnage of paleo-supergene copper mineralization at the top of the deposit.
Table 1. NorthWest Copper Drill Highlights from Kwanika1
Hole |
From (m) |
Interval2
(m) |
CuEq3 (%) |
Cu (%) |
Au (g/t) |
Ag (g/t) |
K-21-217 |
253.2 |
235.5 |
2.65 |
2.00 |
1.21 |
5.3 |
K-08-062 |
130.9 |
610.1 |
1.15 |
0.74 |
0.78 |
1.8 |
K-18-182 |
25.0 |
500.3 |
1.04 |
0.66 |
0.80 |
2.2 |
K-18-180 |
33.0 |
513.9 |
1.05 |
0.64 |
0.80 |
2.1 |
K-16-177 |
160.0 |
438.4 |
1.14 |
0.71 |
0.83 |
2.0 |
K-20-198 |
214.7 |
697.6 |
0.83 |
0.40 |
0.65 |
1.9 |
K-22-255 |
152.2 |
399.8 |
1.01 |
0.62 |
0.74 |
2.0 |
K-07-015 |
27.4 |
328.3 |
1.04 |
0.72 |
0.61 |
1.8 |
K-21-210 |
263.5 |
416.5 |
0.74 |
0.44 |
0.57 |
1.6 |
K-21-210 |
263.5 |
416.5 |
0.74 |
0.44 |
0.57 |
1.6 |
K-22-242 |
339.3 |
304.2 |
0.75 |
0.47 |
0.53 |
1.7 |
K-18-183 |
407.4 |
312.0 |
0.83 |
0.45 |
0.73 |
1.8 |
Note 1: See NI 43-101 technical report titled “Kwanika-Stardust Project NI 43-101 Technical Report on Preliminary Economic Assessment” dated February 17, 2023, with an effective date of January 4, 2023, filed under the Company’s SEDAR profile at www.sedar.com .
Note 2: True widths of the reported mineralized intervals have not been determined
Note 3: Assumptions used in USD for the copper equivalent calculation (CuEq) were metal prices of $3.50/lb. Copper, $1,650/oz Gold, $21.50/oz Silver, and recovery is assumed to be 86.0% for copper, 63.5% for gold and 61.6% for silver. The following equation was used to calculate copper equivalence: CuEq = Copper (%) + (Gold (g/t) x 0.5078) + (Silver (g/t) x 0.0064)
Figure 3. Example of High-Grade Mineralization with Chalcopyrite and Bornite from the Kwanika Central Zone. KW-180 388.4 metres depth
Figure 4. Image showing continuity of the Kwanika Central Zone Deposit.
Kwanika South Zone. The South Zone is a discrete Cu-Au-Mo-Ag porphyry deposit that is located approximately 1.5 km southeast of the Central Zone open pit resource. In comparison to the Central Zone, the South Zone is slightly younger, has a more polymetallic metal signature that includes significant molybdenum, and is hosted by a distinct, equigranular quartz monzonite intrusion. The South Zone has an open pit resource that adds important tonnage to the Kwanika-Stardust Project and which remains open to expansion.