Crystal Hill GAIP Geophysical Survey

Abstract

Crystal Hill prospect is located within the Murphy Project, adjacent to the Queensland border in the Murphy Inlier. The inlier hosts the historic Pandanus Creek mineral field, which contains a number of mineral occurrences including precious metals, base metals and uranium. In 2023, Lagoon Creek Resources undertook low impact geochemical exploration at the Crystal Hill prospect, an historic target which was superficially worked in 1959 by BHP, which intersected zones of >12% Sn and processed >7kt at 0.32% SnO2. Geochemical sampling across Crystal Hill failed to repeat these Sn grades, however, tungsten in soils reported up to 0.38% WO3. Further geochemical characterisation showed the Crystal Hill granitoid to be enriched in Bi + W + Sn + Mo + Cu. In September and October 2024, Lagoon Creek Resources undertook a Gradient Array Induced Polarisation (GAIP) survey on the Crystal Hill. The survey comprised both Gradient Array (GA) and Pole-Dipole (PDIP) configurations. The Crystal Hill GAIP survey consisted of four adjoining Gradient Array (GA) blocks located across the Crystall Hill topographic high. One PDIP line, 1200m long, was also completed based on the results of the GAIP survey. The GAIP Resistivity results show a dominant SW to NE grain with numerous linear zones of higher resistivity following that trend. There are two small chargeability highs in Block 2 of the GAIP survey (southern block) and one of these was chosen for follow up with PDIP Line 10600N. There is a discrete chargeability anomaly centred on 20800E that the 2D inversion modelling resolves into a vertical chargeable source. This corresponds with the small chargeability high in the GAIP. The chargeable zone is up to 13 mV/V in the model section which is moderately chargeable. It starts at surface and has an indicated depth extent of around 100-150m. The chargeability anomaly on 10600N could be related to disseminated sulphide mineralisation. It would be expected that several percent of sulphide (2%-3%) would be required to produce this chargeability anomaly. The results of the GAIP survey provide a compelling target for drill testing in 2025.