Exploring for gold using radiometrics, magnetics, and petrophysical information in the Warrawoona greenstones of the East Pilbara, Western Australia

The Warrawoona Gold Project is located 25 kilometres southeast of Marble Bar in the East Pilbara region of Western Australia. Key prospects include the Klondyke deposit, which forms the main share of the 1.25 Moz gold resource owned by Calidus Resources Limited. Intense deformation is localised in the narrow zone between the Mount Edgar and Corunna Downs batholiths, and which manifests as strong shearing, steeply dipping lineations, sheath folds and steeply plunging isoclinal fold hinges. Physical property measurements and borehole surveys have shown that ore-bearing structures containing sericitic alteration may be identifiable at the regional to project scale using potassium from radiometric data. Magnetite-destructive alteration and structural complexities relating to the compression and elongation of the greenstone units are also associated with mineralisation. The project area is well exposed with minimal regolith cover. A regional 25m line-spaced airborne magnetic and radiometric survey was acquired across the project in 2020, with a north-south orientation, greatly superseding previous regional data of 100m - 400m line spacing. The detailed datasets have been used to identify radiometric potassium anomalies, which are generally mappable as stratigraphy-parallel elongate zones across the project area. Using the magnetic data, these zones were then assessed for structural complexity as a proxy for mineralisation traps, and for evidence of magnetite destruction as a proxy for alteration. The magnetic and radiometric interpretation was integrated with published outcrop geology maps and local topography information. A total of 95 target areas were identified, including an untested trend to the west of the Klondyke deposit.Open-Access Online Publication: March 01, 202