Geophysics and Drilling Collaborations Round 17 Innovative Targeting Brunette Downs Project ELs 32708 32709, 32710, 32714 Final Report

Abstract

Red Metal Limited (Red Metal) is the owner and operator of ELs 32708, 32709, 32710 and 32714 which form the company's Brunette Downs project located 185 km north-east of Tennant Creek. The project area is underlain by sediments belonging to the Georgina Basin that cover the southern margin to the greater McArthur Basin and southwestern end of the Brunette Downs rift corridor, as defined by recent work by Geoscience Australia (GA) and the Northern Territory Geological Survey (NTGS). Interpretation of seismic data from the Barkly 2D Deep Crustal Reflection Seismic Survey (line 19GA-B1) suggests that below approximately 200 m of Neoproterozoic-Phanerozoic Georgina Basin and 500 - 1500 m of Neoproterozoic South Nicholson cover, the rift corridor contains up to 1200 m of Paleoproterozoic - Mesoproterozoic Isa Super basin sediments (Glyde package of the McArthur Basin). The rift is divided into two moderately south southeast-dipping packages and while the prospective rocks are greater than two kilometres deep on the southern margins of these corridors, in the Lake Sylvester area they are at potentially explorable depths. The tenements straddle the interpreted south margin to the Greater McArthur Basin and the Brunette Downs rift corridor and target the Neoproterozoic and Middle Proterozoic sequences adjacent to the deep-penetrating basin margin faults for sediment-hosted copper-cobalt and zinc-lead-silver deposit styles. A priority target is a potential stratigraphic conductor visible in GA's airborne electromagnetic data (flight line 1,200,003) situated adjacent to a significant, deep penetrating, basin margin fault interpreted from the seismic data. Initially Red Metal proposed to conduct four north-south magnetotelluric (MT) survey lines across the northern margin of the Brunette Downs rift corridor and to validate the airborne electromagnetic conductivity feature identified from GA's airborne EM survey. Due to the area receiving unseasonally high rain fall during 2022 - 2024 access to proposed survey sites was restricted and the survey was reduced to one line comprising 20 stations at one kilometre intervals. The survey was conducted by Moombarriga Geoscience (Moombarriga) from 20/09/24 to 29/09/24. The survey encounters three conductive features of which Feature 1 and Feature 2 were found to be real. Feature 1 was interpreted to represent a deep vertical basement feature possibly a fault zone. Feature 2 is a flat lying high conductive (low resistivity) stratigraphic feature that may represent a conductive, carbonaceous shale towards the base of the Roper Group. This horizon is interpreted as the first reductant within the largely oxidised quartz clastic Roper Group sequences that may have potential for sediment-hosted copper-cobalt mineralisation. A drill test of the feature is being considered.