Dykes, Synclines and Geophysical Inversion – is geology important?

Abstract

In the last 10 years, the average depths of cover for gold and base metal discoveries was 60 and 128 metres respectively (Schodde, 2017). Existing methods of geophysical search techniques appear to lose their practical effectiveness below ~200m. This lack of success has been highlighted as part of the general UNCOVER movement in Australia. A critical and thoughtful response requires not just handwringing, but careful improvements to the whole methodology of exploration geophysics. Clever methods that do not work effectively, can mask this lack of success for a period. The original popularity of the magnetic method is revisited and suggestions are made for what works at depth and what does not. New Airborne ElectroMagnetic 2.5D inversion technology promises to regularly reach to 500m in most terrains, and produce geological sections with marker beds, indicating the local folding and faults.