Partial Relinquishment Report for Exploration Licences 32765, 32766, 32771, 32777, 32778, 32780, 32783 (11th March 2022 to 7th March 2025) and Exploration Licence 33463 (28th February 2023 to 28th February 2025) and Exploration Licence 33694 (28th February 2024 to 4th March 2025) for Group Annual Report (GR580) Irindina Project

Abstract

This report summarises the partial relinquishment of 527 blocks over nine exploration licences (ELs) 32765, 32766, 32771, 32777, 32778, 32780, 32783, 33463 and 33694. These tenements comprise part of the IGO Newsearch Pty Ltd (IGO) Irindina Project under the Combined Annual Reporting Group 580 (GR580 Irindina Project). The first of these tenements were granted on the 11th of March 2022. Based on the revised tenure area, the closest Irindina Project granted tenement to Alice Springs (EL33694) is located approximately 110 km northeast and intersects the Plenty Highway. The 9 Irindina tenements subject to partial relinquishment are located on the Mount Riddock, Huckitta, Jinka, Dneiper, Macdonald Downs, Indiana, Delny and Jervois Pastoral Leases. The Irindina project primarily targets orthomagmatic nickel-copper-cobalt sulfide mineralisation within ultramafic and mafic bodies that intrude metasedimentary rocks of the Irindina Province. Several Paleoproterozoic to Paleozoic mafic and ultramafic intrusions are also reported in host rocks of the Aileron Province. No on-ground exploration work was completed on the relinquished tenure since grant (11th of March 2022 to the 7th of March 2025). Two airborne surveys were completed over portions of the relinquished ground since grant. A preliminary aeromagnetic and radiometric survey was completed in October and November 2022 in the east of the project area. The survey covered some of the easternmost relinquished blocks in EL 32778 totaling 40 partial flight lines. The airborne magnetic-spectrometry survey was oriented north-south at 100 m line spacing and 1000 m tie lines, with a nominal terrain clearance of 30 m. The aim of the survey was to generate higher resolution magnetic imagery that might allow more robust geological and structural interpretations of targeted rocks undercover, particularly mafic intrusions that may host orthomagmatic nickel-copper sulfide deposits. The survey was co-funded under Round 15 of the Northern Territory Government's Geophysics and Drilling Collaboration (GDC) Program. An airborne electromagnetic survey was completed in October and November 2023 in the northeast and centre of the Irindina project area. This Helitem2 300-m-line spaced survey covered 147 partial flight lines over relinquished ground in EL 32765, EL 32777, EL 32778 and EL 32783. The survey was conducted using a helicopter-towed time-domain EM system (6.25Hz Helitem2). The Helitem2 system transmitted a 560,000Am2 square wave-pulse via a 35 m rigid loop transmitter. The survey was flown as north-south or northwest-southeast flight lines with 300-m spacing. The towed EM system was draped over topography at a nominal altitude of 35m. The aim of the survey was to directly detect any electromagnetic conductors beneath shallow cover on flight lines (which may correspond to sulfide mineralisation). The survey also allowed areas of shallow and moderate cover to be mapped accurately and define explorable areas for future on-ground activities. Part of the eastern survey was co-funded under Round 16 of the Northern Territory Government's GDC Program. IGO have relinquished ground for five reasons. Relinquished areas well covered by good quality airborne electromagnetic surveys flown by IGO or historical industry explorers are considered well tested (containing no follow-up anomalies for ground EM), and/or are deemed unexplorable based on the interpreted depth of cover to basement rocks. This makes further exploration by ground EM or soil sampling impractical with current methods. Other areas were relinquished if they contained heritage exclusion zones, were located close to local communities, or were sub-blocks that cannot be explored effectively using airborne surveys due to their small area.