Document Type

Conference Paper

Publication Date


Publication Details

This conference paper was originally published as Armstrong M and Rodeghiero, A, Airborne Geophysical Techniques in Aziz, N (ed), Coal 2006: Coal Operators' Conference, University of Wollongong & the Australasian Institute of Mining and Metallurgy, 2006, 113-131.


Airborne geophysical surveys have been used extensively in the mineral exploration industry predominantly for the delineation of metalliferous deposits. Recent advances in technology and the integration of multiple geophysical data-sets including aeromagnetic, radiometric and gravity surveys can provide useful information on lithology and structure. Additionally advances in data analysis, processing and image enhancement techniques have improved the resolution of geophysical datasets so that very subtle variations in the geophysical responses can be identified. High resolution aeromagnetic and radiometric surveys have recently been acquired over the Dendrobium mine district in the Illawarra Coal Fields. The primary objective of this survey was to delineate any igneous intrusive deposits that may impact on underground Longwall mining operations. A range of enhancement techniques were also applied to the data to improve resolution and delineate the lateral distribution of sills at depth as well as anomalous features associated vertical/sub-vertical dyke deposits that may or may not reach the surface. Airborne gravity gradiometer technology has also been successfully used to explore for a range of ore types (iron ore, kimberlites) and for geological mapping. BHP Billiton has successfully demonstrated that the FALCON airborne gravity gradiometer (AGG) can be used over sedimentary basin environments and has detected deep channels in the Gippsland Basin. A survey in the Latrobe Valley successfully delineated the coal horizons (Rose, 2005). Detailed modelling has been completed to determine whether airborne gravity techniques would be useful, specifically for delineating igneous sills at depth in the Illawarra Coal Fields. Some doubts have been raised on the suitability of this technique due to the nature of the topography, depth of cover and the lack of density contrast between intersected sills and the host sequences.