The Kudz Ze Kayah (KZK) mineral claims are located within the Finlayson Lake District of the Yukon-Tanana terrane, which underlies much of central Yukon and parts of Alaska and British Columbia. The Finlayson Lake District forms a crescent-shaped area ~300 km long and ~50 km wide that extends from Ross River in the north to Watson Lake in the south, and comprises Devonian-Mississippian volcanic, intrusive, and sedimentary rocks. It is bounded by the Tintina Fault to the southwest, and to the northeast by the Inconnu Thrust.
The KZK claims encompass the ABM and GP4F Zn-Pb-Zu-Ag-Au-rich deposits, both of which are of the volcanic-hosted massive sulphide (VHMS) deposit style. The deposits are hosted within the Grass Lakes Group, specifically the Kudz Ze Kayah Formation which is structurally and stratigraphically overlain by the Wind Lake Formation.
The KZK property, comprising 879 mineral claims covering 159km2, is held 100% by BMC. The first significant exploration activity in the area was triggered after the Geological Survey of Canada released a regional silt and soil geochemical survey. A follow-up geochemical sampling programme, undertaken by Cominco in 1993, led to the discovery of a mineralised cobble in one of the drainages. EM and magnetic geophysical surveys in the vicinity quickly identified a coincident response target, and follow-up diamond drilling in 1994 quickly discovered the ABM deposit. A prefeasibility study completed by Cominco in 1995, and the mining project was permitted in 1998. Cominco, at a time of low metal prices, moved their focus to Red Dog, and KZK project remained effectively dormant until 2015 when BMC acquired the project from Teck (as successor to Cominco). BMC completed a drill out of the ABM deposit in 2015, and step-out exploration drilling toward the end of the 2015 season resulted in discovery of the adjacent Krakatoa Zone. The GP4F deposit was discovered by Cominco in 1998, after a second round of drilling in a coincident magnetic and EM target.
The KZK claims cover the strike extension of the ABM and GP4F host stratigraphy, with the only intensive exploration work having been undertaken in the immediate vicinity of the two deposits. Even then, drilling testing around the deposits is for the most part limited to a maximum of ~200m vertical depth. In this context the highly prospective KZK claims remain relatively untested by modern exploration.
ABM Deposit Geology
The ABM deposit comprises two major zones (ABM Zone and Krakatoa Zone) of continuous shallow-dipping VHMS mineralisation within a thick felsic tuff and intrusive/flow complex. The ABM Zone is primarily hosted within the felsic volcanic package, whereas the Krakatoa Zone is also hosted within a pre-mineralisation mafic sill that intruded the felsic volcanic package. Mineralisation also occurs in the hanging wall to the mafic sill at Krakatoa in what is interpreted to be the equivalent of the ABM mineralised position.
The upper limits of the ABM and Krakatoa Zones are truncated near surface and overlain by glacial sediments. The massive sulphide mineralisation at ABM occurs under ~2 m to 20 m of overburden, is up to ~30 m in true thickness and extends ~500m down-dip, whereas the Krakatoa Zone occurs under ~30 m of glacial overburden, is up to ~22 m in true thickness, and extends for at least 600m down-dip. The down-dip margin of the ABM Zone appears to transition into a mixed volcano-sedimentary package, whereas the Krakatoa Zone mineralisation remains open at depth. ABM mineralisation predominantly comprises massive sulphide, with a lesser component of disseminated, vein-style and banded sulphide ores (“stockwork ore”) which occurs in both the footwall and hanging wall in equal measure.
A post-mineralisation brittle fault zone offsets the ABM and Krakatoa mineralised zones, and angular clasts of sulphide are to be found within the fault zone breccias. The south-eastern margin of Krakatoa is cut by another late brittle fault zone, and wide-spaced (~200m) drilling east of the fault during 2016 identified a thin zone of massive sulphide mineralisation in drill hole K16-394 (0.5m @ 9.3% Zn, 0.2% Pb, 0.5% Cu, 8g/t Ag) which remains to be followed up.
GP4F mineralisation is hosted within an interbedded sequence dominated by highly foliated and altered felsic volcaniclastic and pelitic sediments, with lesser quartz-phyric porphyritic intrusives and mafic dykes. The host rocks are interpreted to be the distal facies equivalent of the ABM host rocks, with a significantly reduced intrusive component. GP4F mineralisation predominantly comprises disseminated to semi-massive sulphides within phyllosilicate-dominant schists. The deposit occurs under ~10 m to 25 m of glacial overburden, is up to 8 m in true thickness within which massive sulphide intervals of up to 3.2 m in thickness occur, and has an east‐west strike extent of ~300 m and a down‐dip extent of ~350 m. The deposit remains open both along strike and down‐dip.