Regional Scale Geophysics Jessica Project EL's 32493, 33332, 33334 and 33742

Abstract

Taragon Valley Pty Ltd (A wholly owned subsidiary of South32 Ltd) has successfully completed the regional scale airborne electromagnetic VTEM survey over the northeastern portion of the Jessica Project as part of the Geophysics and Drilling Collaborations Program Regional Scale Geophysics Round 18. 2025-2026. The Geophysics and Drilling Collaborations program co-funds industry exploration programs to advance geological understanding and resource development in the Territory. The outcomes of the program are expected to improve geological knowledge and mineralisation targeting within a region, particularly at depth. The aim of the Jessica VTEM survey was to collect high resolution magnetic and electromagnetic data over the northeastern portion of the Jessica project considered prospective for sediment hosted Zn & Cu mineralization to aid with interpreting and mapping favorable geological lithologies and structures. The survey was flown UTS Geophysics Pty Ltd between 18th September - 14th October 2025. Principal geophysical sensors included a versatile time domain electromagnetic (VTEM Max) system, and a cesium magnetometer. Ancillary equipment included a GPS navigation system and a radar altimeter. A total of 2,765 line-kilometres of geophysical data over two blocks-Western Block and Eastern Block (approx.. 1268km2) at 800m & 400m line spacing respectively - was acquired during the survey. Northern Australia sediment hosted Zn / Cu systems are hosted by / associated with carbonaceous shales and siltstones which can be mapped using electromagnetics (EM). The copper ore and gangue mineral assemblage also often have a significant EM response Within the survey area the Paleoproterozoic rocks of interest are concealed beneath younger, and often resistive sediments. The VTEM data is considered a useful tool for identifying structures, prospective conductive lithologies and more discrete accumulations of sulphides within the top 300m of surface. The newly acquired VTEM data compliments and builds on the available regional datasets in the area while assisting South32 with future exploration targeting.