Innovative airborne geophysical strategies to assist the exploration of critical metal systems

Critical metals are essential in sustaining the high technology and the green energy transition of modern societies. The future discovery of new critical metal deposits will likely be made at increasing depths and under thick cover sequences. The key roles of the four airborne geophysical exploration methods, gravity, magnetometry, electromagnetism and gamma-ray spectrometry, are reviewed in this article. The measured data from airborne magnetic, gravity and electromagnetic surveys can be inverted to reveal the distribution of underlying mineral prospects in terms of magnetic susceptibility, density and electrical resistivity/conductivity beneath the surface.

The interpretation of geophysical data is important in relating geophysical responses to the lithology and geophysical anomalies to potential exploration targets that are concealed under cover. Gamma-ray spectrometry can identify near-surface hydrothermal alteration zones and uranium systems. Structural complexity maps can provide additional key parameters for the exploration targeting of structurally controlled critical metal systems. We briefly discuss the application of airborne geophysical methods to efficiently guide the exploration of concealed critical metal deposits. A robust understanding of the geological setting of the respective mineral prospect is the most relevant factor in choosing the most efficient geophysical exploration strategy. Geophysical tools will likely play an increasingly important role in guiding the future discovery of concealed critical mineral systems.