Using regional aeromagnetic data, our method firstly identifies lineaments as a reliable indicator of geological structures, exploiting a combination of texture analysis and contrast invariant ridge detection to find laterally continuous textural ridges. Using the detected lineaments, two scenarios of local structural complexity are explored: feature intersection density based on the number of faults intersections and splays; and feature orientation diversity representing deviations of strike of lower order faults and ductile shear zones. The local structural complexity is visualised using heat maps that highlight the regions of structural complexity.
The method has been tested using aeromagnetic data from the Archean Eastern Goldfields Superterrane of the Yilgarn Craton in Western Australia and a region from the Archean Abitibi greenstone belt in the Superior Craton, Ontario, Canada. Both cratons are mature exploration areas where granite-greenstone terrains host numerous orogenic gold deposits. The regions selected by the proposed system as most structurally complex, and hence prospective, correlate with the known gold deposits in these areas.