Application of high resolution aeromagnetics to petroleum search in the southern Amadeus Basin

Abstract

The regional airborne magnetic survey of the Amadeus Basin, which was done by the Bureau of Mineral Resources (BMR) in 1965, indicated maximum basement depths of 6000 m below sea level, and also detected some smaller wavelength magnetic anomalies attributed to dyke swarms or volcanics within the sediments. These anomalies were not properly resolved by the widely spaced flight lines. One of the short wavelength aeromagnetic anomalies, between Curtin Springs and Ayers Rock, was investigated by BMR with ground magnetic traverses and drilling in 1981. Two drill holes intersected dipping volcanics about 100 m below the surface. The volcanics were underlain by inter-bedded grey shale and evaporites. The inference that the magnetic sources are volcanics near the top of the Bitter Springs Formation, and the existence of similar anomalies in adjacent parts of the Amadeus Basin, provided the rationale for a low level survey to assist structural mapping of the sedimentary sequence.