Summary:
Ni-Cu-Co-PGE mineralisation is located at or near the base of subvolcanic mafic-ultramafic intrusive complexes referred to as the “Raglan Formation”. Resources are generally determined at a 1.5% Ni cut-off and are composed of disseminated, net-textured, and massive pyrrhotite-pentlandite-chalcopyrite rich sulphides contained within 131 individual sulphide lenses, extending from surface to more than 900m vertical depth. The size of these high-grade sulphide lenses varies significantly from 0.01Mt to 6.1Mt, averaging 0.2Mt.
The mineralised zones on the Raglan property that were drilled in 2011 and 2012 are named: East Lake, Zone 2, Katinniq, Zone 5-8, Zone 13-14, Boundary and Donaldson.
East Lake & immediate vicinity
Kikialik is located within the East Lake zone that also comprises five mineralized ultramafic complexes labelled Main Sill, South Sill, East Sill, West Sill, and Southeast Sill. The "Sill" nomenclature is maintained because of historic use, and has no bearing on genetics or mode of emplacement. All the five `sills' are characterized by anomalous nickel mineralization.
Gabbro and thick sequences of massive to pillowed komatiitic basalt, often exhibiting flow top breccia and spinifex textures, overlie the Zone 3 ultramafic complex.
Zone 2
Zone 2 is located at the eastern end of the elongated northeast-southwest ultramafic body that also hosts Zone 3 mineralization. The northwest dipping, northeast plunging, ultramafic body is composed of several distinct ultramafic horizons, most noticeable in western Zone 2. The ultramafic rocks are locally intercalated/interdigitated with argillaceous sediments, basalt and locally gabbro, and are predominately underlain by gabbro. Thick sequences of argillaceous sediments and massive to pillowed komatiitic basalt, often exhibiting spinifex-textured, flow top breccia or peperites overlie the ultramafic rocks. The most significant known ore bodies occur along the base of the ultramafics, at or near the footwall contact with the underlying gabbro. Unlike Zone 3 and Katinniq, many of Zone 2 ore bodies do not occur in obvious footwall embayment structures.
Katinniq
The Katinniq ultramafic complex is a 3.0 kilometre long east-northeast trending body, which overlies Povungnituk metasediments and is itself overlain by Chukotat basalts. It consists of overlapping channelized ultramafic bodies (olivine cumulates) that grade laterally and upwards into komatiitic basalts. The ultramafic complex is generally subdivided into a lower and upper ultramafic sequence, referred to as UM1 and UM2 respectively.
Zone 5-8
The Zone 5-8 region is a three kilometre long exposure of mineralized ultramafic rocks, centered four kilometres east of the Katinniq mill. The ultramafics are exposed at surface as two distinct ultramafic bodies referred to as the East and West Ultramafics. The complex dips shallowly to steeply to the north and is interpreted to connect at depth (>700 metres vertical) with the Katinniq ultramafic complex to the west and the Zone 13- 14 ultramafic to the east.
Zone 13-14
The zone 13-14 region is located 9km East of Katinniq.
There are 4 separate ultramafic units (UM 1, UM2, UM3 and UM4). The four units are loosely correlated across the 13-14 area with the exception of UM4 which is restricted to the north-west of the 13-14 area.
Ultramafic 1 (UM1) is the deepest. It is typically separated from the UM2 by 30-100m of gabbro and/or sediment and appears to pinch out updip; as observed in the Eastern part of the belt. UM1 varies in thickness from 20m to >200m and does not appear to be particularly mineralized.
UM2(Complexe 14) hosts lenses 14A, 14B, 14D and 14E and is 100m to 250m thick. In places UM2 is less than 20m thick, hosted in between gabbros and strongly mineralized. The footwall is composed of sediments in the south and changes to a gabbro footwall in the 14B lens area. UM2 dips moderately to steeply (40 degrees to 60 degrees) to the north at the southern contact, where it outcrops. The dip flattens quickly to an average of 25 degrees to the north. In the Northwest corner the UM2 stratigraphy and orientation is not clearly established.
UM3 typically occurs directly in contact with UM2 and marked by a sharp increase in sulphide content. In the western part of the zone UM3 is typically separated from UM2 by gabbro, sediments or basalt. A few sulphide intersections occur in this unit however no ore lens has yet been recognized at this horizon.
UM4 is restricted in area to the northwest corner of 13-14 were it is mapped a distinct ultramafic unit. The maximum thickness of UM4 is 100 meters. The footwall to UM4 is mostly gabbro and also sediments. No sulphide ore lenses have been discovered in UM4.
Boundary
Boundary is comprised of at least three north-dipping ultramafic units of variable thickness (<20 to >200 metres) over a strike length of 3.6km, approximately 3km of which out- / sub-crops in the central portion of the zone. Mineralization occurs at numerous horizons within the ultramafic stratigraphy but generally occurs at the base of ultramafic units in interpreted lava channels where underlying units have been partially or completely removed by thermal erosion. The footwall in the western portion of the zone has been poorly tested to date. Center and Eastern portions seem to be structurally complex; directed by local faults mostly oriented NW - SE.
Donaldson
The Donaldson Ultramafic complex is the most easterly of the known mineralized peridotite bodies found in the Raglan formation. The Donaldson complex consists of Five north-dipping (generally 20-40°) overlapping ultramafic units of variable thickness (<20 to >200m) over a strike length of 2km. Two, northwest striking faults dipping 30-40° are interpreted to have resulted in structural thickening in the central portion of the complex producing a stacked repetition of the main 3 ultramafic units. Ultramafics in the central portion of Donaldson are weakly to non-magnetic, possibly due to removal of magnetite during a weak to moderate carbonitization event after serpentinization. This alteration may have played a role in both upgrading and localizing the mineralization in the ore zones at Donaldson (Dillon-Leitch, 1988).
Mineralization is abundant in each of the 3 major ultramafic units. Ni tenors of mineralization at Donaldson are quite high (>10-20). Sediments are locally Po-rich (locally magnetic), and mineralized zones usually contain some magnetite. Thus, both mineralization and sediments are relatively high in magnetic susceptibility compared to most of the ultramafic bodies at Donaldson.