A new method for building a model of the rock property distribution on an unconformity surface (Pratt et al., 2019) presents new opportunities for greenfield exploration in complex geological environments. The method uses the inherent 3D information present in the magnetic tensor to create a model segment on the unconformity surface for every magnetic anomaly on every line in the aeromagnetic survey. Because the tensor is a 3D spatial derivative of the magnetic field, it automatically reduces the influence of regional magnetic field changes to focus the inversion process on the unconformity surface. An expert AI system builds a coherent 3D geological model from the individual model segments, which it then uses to constrain the joint inversion of the tensor data. We explore the ways in which the maps and rock properties can be used to enhance greenfields exploration by applying the technique to the Cloncurry region of the Mount Isa Inlier. We evaluate the effectiveness of using the compact magnetic rock property estimates to define targets that might otherwise have been missed in the early phase of exploration. Historical airborne data acquired prior to mining of most deposits helps us to design appropriate strategies for targeting similar prospect styles.

Open-Access Online Publication: Feb 24, 2023