AusAEM; acquisition of AEM at an unprecedented scale

Abstract

Exploring for the Future is a four-year programme of the Commonwealth Government that aims to boost Australia’s attractiveness as a destination for investment in resource exploration. A significant component of the data acquisition component of the programme is the AusAEM Airborne Electromagnetic (AEM) Survey. This survey will focus on wide line-spaced acquisition as a regional mapping tool to gather new pre-competitive data and information, on extents never previously attempted. The objectives are to map, at a reconnaissance scale: • trends in regolith thickness, character, and variability • variations in bedrock conductivity • the continuity of key conductive bedrock (lithology-related) conductive units under cover • the groundwater resource potential of the region. The first AEM survey of this programme, when completed, will cover an area of over one million square kilometres (more than the areas of France and Spain together), at a nominal line spacing of 20 km with infill surveys in selected areas for subscription companies. In order to have the greatest impact the survey targets greenfield areas where the resource potential is unknown. The AEM data will contribute to estimating features and character of the cover material. To maximize industry collaboration on the project GA sought, and received, expressions of interest from industry subscribers for infill flying on the regional survey for lines spaced at 200 or 400 meters. Regional AEM surveys improve geological understanding in areas with little or no outcrop. The processed data enables informed interpolations of conductivity between sparse drill-holes and estimates on the depth of the basement-cover interface from geophysical modelling. The modelling results are used to inform follow-up exploration activities thereby reducing exploration risk. The new data will be released to the public domain at regular intervals to promote future activity by the government, exploration and research sectors.