The Kudz Ze Kayah (KZK) project is wholly owned by BMC Minerals, a subsidiary of BMC (UK) Limited. BMC Minerals holds 100% of the rights to the project.
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Summary:
The Kudz Ze Kayah Project area, comprising the Kudz Ze Kayah claim blocks within which the ABM deposit is located, encompasses units of the Grass Lakes group. The surface geology of the property was initially mapped by Cominco in 1996 at 1:20,000 scale (Schultz & Hall, 1997) and subsequently by BMC at 1:20,000 scale in 2017 (Baker et al., 2017).
The ABM deposit (comprising the ABM Zone and Krakatoa Zone) primarily comprises continuous, shallowdipping massive sulphide mineralization hosted within a thick felsic package of volcaniclastics and coherent sill/flow complex that locally make up the Kudz Ze Kayah formation.
Massive sulphide of the ABM Zone is hosted within a felsic rock package, whereas the Krakatoa Zone is predominantly hosted by a pre-mineralization mafic sill located within the felsic volcanic package. Mineralization at Krakatoa also occurs in the felsic hangingwall units stratigraphically overlying the mafic sill, in what is broadly interpreted to be the equivalent of the ABM mineralized position. Only scattered vein-style and disseminated mineralization occurs within the mafic sill lying stratigraphically below the ABM Zone.
The upper limits of the ABM and Krakatoa Zones are truncated near surface and overlain by glaciofluvial sediments. The massive sulphide mineralization at ABM occurs under approximately 2– 20 m of glaciofluvial overburden and is up to approximately 30 m in true thickness, whereas the Krakatoa Zone occurs under approximately 30 m of glaciofluvial overburden and is up to approximately 22 m in true thickness. The downdip margin of the ABM Zone appears to transition into a mixed and variably carbonaceous felsic volcanosedimentary package, whereas the Krakatoa Zone currently remains open at depth beyond the down-dip extent of the mafic sill.
A post-mineralization brittle fault zone (East Fault) offsets the ABM and Krakatoa 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 of the same generation (Fault Creek Fault). There exists a marked difference in the stratigraphy east of the Fault Creek Fault, with recent drilling having identified a package to the east of the fault, dominated by felsic volcaniclastics and minor felsic intrusives, which transitions conformably up into the overlying Wind Lake formation. The marked change in volcanic stratigraphy across the Fault Creek Fault, despite little of no evidence of a significant offset of the Wind Lake formation basal contact, could potentially indicate the presence of a syngenetic fault structure along the south-eastern limit of the Krakatoa Zone. Recent attempts at a reconstruction of the ABM Zone and Krakatoa Zone into a single massive sulphide unit are also not consistent with the degree of movement along the East Fault that is observed at the Wind Lake formation basal contact. These features could indicate the presence of syngenetic fault structures either side of the Krakatoa Zone that was later the locus of late-stage brittle faulting. As such, the area east of the Krakatoa Zone remains a significant exploration target. A schematic geological cross-section through both the ABM and Krakatoa zones.
Mineralization
ABM Zone
Massive sulphide of the ABM Zone is up to 39 m true thickness, extending approximately 700 m along strike and approximately 500 m down dip. It dips to the north-northeast at approximately 35° near surface, transitioning to a dip of approximately 15° at around 200 m depth below the valley floor. The up-dip extent of the deposit is truncated by erosion and covered by approximately 2–20 m of glaciofluvial overburden.
Massive sulphide mineralization of the ABM Zone occurs as several stacked massive sulphide lenses to the west, transitioning to a single massive horizon at around 415,025 m E and extending to approximately 415,250 m E where it is then truncated by the post-mineralization East Fault. Stockwork and disseminated mineralization occurs equally both in the hanging wall and footwall to massive sulphide, and to a lesser degree between massive sulphide lenses.
Sulphide mineralization is dominated by pyrite, sphalerite, pyrrhotite (+ marcasite), galena and chalcopyrite, with minor arsenopyrite and a range of sulphosalts predominantly comprising tennantite-tetrahedrite and freibergite. Both the up-dip part of ABM Zone and most of Krakatoa Zone have elevated sulphosalt content relative to the remainder of the ABM deposit.
Krakatoa Zone
Krakatoa Zone mineralization, bound to the west by the East Fault and to the east by the Fault Creek Fault, is hosted within Kudz Ze Kayah formation that dips at 35° to the north-northeast. Although of lesser extent, the distribution of mineralization within the Krakatoa Zone is more spatially complex than the ABM Zone due to the stacked mineralized lens system. Massive sulphide mineralization occurs within three principal mineralized horizons:
1. The “Upper lens”, broadly interpreted as the stratigraphic equivalent to the ABM lens.
2. The “Main lens”, the major component of Krakatoa Zone in terms of sulphide mineralization with a true thickness up to 22 m.
3. A less pronounced and semi-continuous “Lower lens”.
Krakatoa Zone mineralization is broadly concordant with stratigraphic layering of the host rocks, extending over approximately 200 m of strike, at least 500 m down dip, and up dip to the base of glacial overburden of 20–30 m thickness.
Several pre- to syn-mineralization growth faults are thought to influence the massive sulphide bodies at Krakatoa in terms of offsets and changes in massive sulphide thickness. Both the large coherent mafic and aphanitic rhyolite bodies appear to have an influence on the spatial distribution of sulphide mineralization. As these bodies are themselves mineralized, it is likely that these coherent bodies acted as fluid aquacludes during mineral deposit formation.
Host rock types and alteration styles of Krakatoa Zone mineralization are for the most part similar to those encountered in the ABM Zone. The key difference is the degree of mineralization associated with the mafic sill, which below ABM Zone is only poorly mineralized. The Main lens comprises the bulk of mineralization at Krakatoa, with massive sulphide occurring both within the felsic volcanics immediately beneath the mafic sill, and within the mafic sill, after replacement of enclaves of felsic volcaniclastics and/or replacement of the mafic sill itself.