Summary:
Kwanika Deposit Types
Kwanika hosts porphyry Cu-Au deposits, classified into alkalic, transitional, and calc-alkalic sub-types. The Central Zone has features of both alkalic and calc-alkalic sub-types, with mineralization linked to a monzonite and strong quartz stockwork. The South Zone is a structurally controlled calc-alkalic deposit in quartz monzonite to quartz monzodiorite, featuring Cu-Au-Ag-Mo mineralization in quartz veins and intense K-spar ± silica flooding.
Stardust Deposit Types
The exploration model for the Stardust property links several mineralization types: porphyry, skarn, carbonate replacement, vein, and sediment-hosted deposits. Cu-Au-bearing garnet skarns replace limestone adjacent to a mineralized porphyry stock. Outboard of the skarns, carbonate replacement massive sulfides (CRD) occur as mantos and chimneys. Sulphosalt veins can occur beyond the CRD or overlie them in leakage zones. The distal end member is the sediment-hosted Au-As-Sb (Carlin-type) deposit.
Kwanika Property
The Kwanika project consists of two mineralized areas: the Central Zone and the South Zone.
Central Zone
The Central Zone is 1,400 m long by 400 m wide and extends more than 700 m below the surface. The western part of the zone is downfaulted by the Central fault and cut off by the Pinchi fault further west. Mineralization is mainly hosted by a quartz monzonite porphyry complex. This porphyry intruded Takla Group andesitic rocks in the west and pre-mineral quartz monzodiorite-diorite intrusions in the east. These rocks are partly overlain in the west by Early Cretaceous sedimentary rocks within a west-dipping half-graben. East of the Central Fault, the zone comprises a steeply-dipping quartz monzonite porphyry with similar grade contours and alteration shells. West of the Central Fault, these features are shallowly to moderately dipping to the west.
Central Zone Alteration and Mineralization
Hydrothermal alteration in the Central Zone comprises an inner potassic core surrounded by an outer potassic shell that yields to a peripheral propylitic zone, all of which are variably overprinted by patchy sericite alteration. The inner potassic zone consists of creamy to pale pink secondary K-feldspar with minor albite, whereas the outer potassic zone comprises pink to red secondary K-feldspar and lesser biotite, cut by minor biotite, tourmaline, gypsum/anhydrite and magnetite veinlets. Both potassic zones contain small patches of less altered rock characterized by sericite-altered plagioclase and chlorite-altered biotite and hornblende. Rare, narrow, dyke-like bodies of hydrothermal breccia occur within 150 m of the bedrock surface in the central part of the zone and contain rotated and rounded fragments of highly silicified quartz monzonite (<1 cm to >6 cm long) in a matrix of quartz, pyrite, chalcopyrite, and tourmaline.
South Zone
The South Zone is 2,200 m long by about 330 m wide, and locally extends more than 600 m below the surface. The highest copper grades occur in a steeply-dipping, 800 m long tabular body in the northwest part of the Zone, with an upper part extending to the east. The South Zone is ovoid in plan and is confined to a northerly trending corridor bounded by the West and East faults. The West fault zone widens from 3 m to 5 m near the surface to a 75 m wide crushed zone at depth, and dips steeply to the west. The east side of the South Zone is not well-delineated, due to limited drilling, but the steeplydipping East fault can be recognized by resistivity and chargeability highs and was confirmed in hole K-10-155 by a 2 m intersection within a broad zone of sericite alteration.
South Zone Alteration and Mineralization
Potassic alteration in the South Zone is characterized by red to orange secondary K-feldspar, which occurs as pervasive flooding and in envelopes around quartz veinlets and fractures. This zone has been brecciated and replaced by fine-grained quartz. Sericite alteration replaces feldspars, while overprinted zones include chlorite, quartz, and pyrite with minor biotite. A surrounding propylitic zone includes epidote, hematite, chlorite, carbonate veins, and late-stage quartz veinlets.
Mineralization includes pyrite, chalcopyrite, and minor molybdenite along micro-fractures and as disseminations within fine-grained quartz and iron-rich alteration. Rare quartz veinlets with pyrite and chalcopyrite, along with molybdenite in fractures, are present. Pyrite is ubiquitous, and minor sphalerite, galena, hypogene chalcocite, tetrahedrite, bornite, and enargite are found mainly in the northern half. These minerals are contemporaneous. There is no significant supergene mineralization.
Stardust Property
The Stardust property is underlain by strongly deformed Pennsylvanian to Permian Cache Creek units, forming west-dipping folds that plunge north at shallow angles. These folds are subparallel to the Pinchi Fault. Stratigraphy mainly strikes at 320-330°, with dips varying due to intense deformation. This deformation complicates stratigraphic interpretation. Despite this, local conformability to the stratigraphic column has been reported, making interpretation feasible. Limited outcrop and observed sedimentary slump structures add to the challenges.
Stardust Mineralization
Several styles of mineralization that are zonally related to each other are present on the property. From most proximal to most distal from the Glover Stock, they are:
• Molybdenum-Copper-Gold Porphyry consisting of quartz-K-spar, pyrite, molybdenite and/or chalcopyrite veinlets associated with potassic, sericitic, and propylitic alteration in intrusive rocks (Glover Stock).
• Multi-stage Garnet-Diopside skarn cut by Cu-Au-Ag-Zn bearing structures with surrounding dispersed Cu-Au mineralization (Canyon Creek Skarn).
• Structurally and stratigraphically controlled massive sulphide Zn, Au, Pb,
• Ag, Cu replacement bodies [CRD] (4b, 3, and 2 Zones) and their oxidized equivalents.
• Sulphosalt-rich veins (Zone 1) which follow faults and are strongly associated with fine-grained, linear, felsic dykes containing high values of Au, Ag, Pb, Zn, Sb and Mn.
• Mercury mineralization in limestone proximal to the Pinchi Fault.
• Sediment-hosted gold mineralization in limestone.