Geophysical and geological modeling to understand gold mineral systems in the West Arunta Orogen, Western Australia

The West Arunta Orogen (WAO) is a Paleoproterozoic basement complex located in remote east-central Western Australia. Past mineral exploration in WAO has been minimal. A new integrated interpretation using all available geoscientific data from the WAO has been completed. The area is interpreted as a basement-involved, thick-skinned, thrust terrain with fault blocks comprising both the basement and rocks from overlying sedimentary basins. The GIS-based prospectivity analysis relies on the resulting 4D geological history and on the mineral systems approach. For the prospectivity analysis, both a knowledge-driven Fuzzy model and a data-driven Weights-of-Evidence model were implemented. These methods compare spatial distributions of various targeting criteria (represented by predictor maps). The approach involves creation of a series of predictor maps based on the occurrence of geological features associated with the relevant model for deposit formation. The newly-interpreted geology of the WAO constitutes the basis for prospectivity analysis for various commodity types using critical individual targeting criteria (source, pathways, chemical and physical traps), although only the results for orogenic gold are described here. The outputs from both conceptual and empirical prospectivity analyses were compared to identify the most prospective areas for gold exploration in WAO. One of these areas contains known gold mineralisation.