In 2017 Noront commissioned an independent study on the gold prospectivity in the Ring of Fire. The objective of the study was to determine if the region possessed geological characteristics favorable for a sizeable gold deposit, and if so, where. Results of the study confirmed Noront’s view that the Ring of Fire holds great potential for gold discovery and identified four main areas to focus initial exploration. Based on this report, Noront staked an additional 150 claims (2,086 claim cells) in 2017 covering these priority areas (figure 1).
Area 1 is situated along the southwest margin of the Ring of Fire, along the trace of the Webequie Shear Zone (WSZ) and north of the Butler volcanic belt. Shearing along the WSZ shows obvious dextral deflection of a probable gneissic fabric in the central gneiss complex to the north and attenuation of both the western and eastern limbs of the Butler volcanic belt to the south (figure 2). The Butler volcanic belt is interpreted here to be a re-folded fold with axial planar faulting and associated alteration within fold limbs, a deformation pattern similar to the Red Lake gold camp. Past exploration on the property focused exclusively on base metals (Cu-Zn, Ni-Cu-PGE-Cr, Ti-V) due to the presence of sulfide conductors associated with volcanic and mafic-ultramafic intrusions.
As such, the length of the WSZ and its secondary structures have never been tested for gold mineralization in Area 1. Lake sediment sampling by the OGS has identified a cluster of gold anomalies along the western margin of the Butler property, immediately south of the WSZ (figure 2).
Area 2 is situated in the northwest margin of the Ring of Fire, along the trace of the South Kenyan Fault Zone (SKFZ) where it straddles a younger clastic sedimentary belt adjacent to older Muketei age volcanic and intrusive rocks (figure 3). Tight folding and faulting of the supracrustal sequence immediately south of the SKFZ is evident in the magnetic fabric. Stream sediment samples collected during past diamond prospecting campaigns returned up to 5.5 g/t Au at the interpreted break between the sedimentary and volcanic belts. As with Area 1, the SKFZ in Area 2 has never been tested for gold mineralization.
Area 3 lies along the eastern continuation of the WSZ as it sharply transitions from an east-southeast to east-northeast trend (figure 4), broadly defining the boundary between the Muketei (2734Ma) and Victory (2780Ma) Assemblages.
Mesothermal gold mineralization has been drilled at numerous locations in Area 3, most notably along the Triple-J fault, a parallel structure 1km north of the WSZ which truncates the Double Eagle Intrusive Complex (figure 5). Other gold occurrences in Area 3 include Triple-J South, AT4, the Thunderbird Fault, and numerous narrow vein intersections within the ultramafic sills at Black Thor and Big Daddy.
Until recently exploration in Area 3, aside from drilling at Triple-J, has focused exclusively on base metals. In summer 2020 Noront executed a soil sampling program targeting gold mineralization in the WSZ and Thunderbird grid areas (figure 4). The results are highly encouraging and are presented in the sections for Triple-J and Thunderbird Fault. Additional gold soil sampling will be performed in Area 3 along prospective structures as a first pass screening tool.
Area 4 is located along the eastern portion of the Ring of Fire and covers a portion of the Tappan Assemblage (<2702Ma), a younger clastic sedimentary basin which likely lies in unconformity overtop the Attawapiskat Assemblage (>2811Ma) (figure 6). Several major structures coalesce in Area 4, including the WSZ to the south, the Muketei Assemblage boundary to the west, and presumed unconformities in the centre and east.
The OGS have interpreted the presence of tightly folded iron-formation in Area 4 which locally displays magnetic dropouts possibly related to faulting and/or alteration in the iron-formation. In addition, small, late felsic intrusive plugs are observed in the magnetic pattern along presumed unconformity boundaries (figure 6).