2013 Honorary Lecturer
Aeromagnetics–A Driver for Discovery & Development of Earth Resources
Aeromagnetic surveys are very commonly under-interpreted. The potential value, captured during acquisition, is all too often unrealised at the interpretation and ‘action' stages of a project. This presentation illustrates the fundamentals of robust aeromagnetic interpretation using telling case studies.
The two keys to astute interpretation are:
1. Understanding and full integration of local geology
2. Adequate time applied to observation and interrogation of the aeromag
These tasks are very largely qualitative and simple (in a geological context), but they do take time. Fancy hardware and software is no substitute for incisive geological reasoning, and such reasoning cannot occur without time-consuming observation and data integration.
The four studies presented will be:
- The Kalgoorlie district, where scant outcrop in an 80Moz goldfield can be integrated with semi-detailed aeromagnetics to produce geological maps that accurately guide exploration.
- The Amadeus Basin, where again, patchy outcrop and almost no gravity or seismic data limit assessment of the exploration potential. Aeromagnetic data here provides a platform for understanding both basin and basement architecture, and a reliable guide to seismic planning.
- The Galmoy – Lisheen carbonate-hosted Zn-Pb district, where (yet again) superficial cover is a major barrier to effective exploration. Aeromagnetics in this hitherto ‘non-magnetic' environment maps both structure and stratigraphy and becomes a driver for on-ground prospecting.
- The Golden Dyke district. This is perhaps the most informative study. It is a very small area with very good outcrop that is very well mapped. The integration of modest quality aeromagnetics unveils a coherent structural picture and directly points to potential alteration systems. The extraordinary return for a very modest investment in aeromagnetics is a salutary lesson that the method often achieves its best results in areas where we (think we) know a great deal about the geology.
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