Maximising value from aeromagnetics in the search for cleaner-energy and rare earth materials
| Autor: | Yvonne Wallace, Teagan Blaikie, David Isles, Karl Weber |
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| Jazyk: | angličtina |
| Rok vydání: | 2023 |
| Předmět: | |
| DOI: | 10.5281/zenodo.7980537 |
| Popis: | The generation of insightful, working geological maps allows for identification, follow up and refinement of key exploration target criteria across all commodities including rare earths, lithium, nickel, base metals, copper, gold and uranium. Modern high sensitivity magnetometers combined with low noise acquisition, and well-refined quality control processes allow for the identification of subtle anomalism within all terrains including low magnetic contrast sediments. At a ballpark average of $10 per line km, the fixed wing acquisition of aeromagnetic data proves as cost effective now as it did 50 years ago. Flight line spacing and flight height can be selected to provide exceptional unbiased spatial resolution to suit a wide range of geological requirements. Methodical integration of effectively processed magnetic imagery with outcrop, drill hole, gravity survey and other datasets, can be carried out at typical exploration scales ranging from district - 1:250,000 - all the way to mine 1:2,500. A step-wise 'zooming-in' approach to interpretation maximises geological value gained from the data and provides focus and confidence in targeting and field exploration activities. We present a case history from the Tanami region of the Northern Territory and Western Australia, where the use of aeromagnetic data integrated with gravity and seismic surveys has outlined the geological context for known rare earth and gold mineralisation at 1:250,000 scale by mapping major structural and intrusive features. New exploration is driven by interpretation at 1:50,000 scale which refines the search space by the mapping of folds, secondary faults, splays, intersections, terminations, contacts and intrusive complexes. Zooming-in further to the Castella - Watts Rise REE trend we utilise 50m line spaced aeromagnetic data to interpret at 1:5,000 scale. We trace the Killi Killi unconformity, and important cross-cutting structures associated with elevated rare earths in soil and rock geochemistry. Airborne radiometric data, acquired along with the fixed-wing magnetics, assists with the mapping in partly exposed areas and highlights associated uranium anomalism. Overall, the airborne survey data provides a mechanism for progressively reducing the search space and guiding onground exploration. Open-Access Online Publication: May 29, 2023 |
| Databáze: | OpenAIRE |
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