Geochemical landscape evolution and Pattern Similarity Analysis at tenement scale for gold exploration in Forrestania

The present study investigates the Forrestania area, located in the Yilgarn Craton, Western Australia, as a case study to combine geochemical landscape evolution and pattern similarity analysis techniques. In the research area within Forrestania, the dioritic basement is overlain by ~40-~85 m of cover (saprolite and transported sediments). In the basement, Au correlates with As (r2 = 0.90); in the lower saprolite unit, Au correlates with Ba (r2 = 0.91); and in the soil Au is associated with carbonates. The saprock and the lower/mottled saprolite unit preserve the basement geochemical footprint. However, metallic vertical dispersion processes in the area are not efficient due to the presence of three geochemical barriers/gradients. These barriers/gradients are (1) the smectite/nontronite and kaolinitic units, (2) the lacustrine and fluvial sediment transported cover, and (3) the soil. Overall, Au mines and prospects in the region are located within erosional landscape regimes, and the main Au soil anomalies are also located on the slopes of landscape erosional landforms. Pattern similarity analysis (PSA) has highlighted three prospective areas for Au exploration in the Forrestania Greenstone Belt with respect to the best Au drilling intersection at Lady Ada/Blue Haze mine (~70 ppm Au). This targeting workflow methodology can be applied to any similar mineral exploration context in Australia.