Abstract The integrated interpretation of aeromagnetic data is a key exploration tool to define the concealed, potentially prospective geology that we plan to explore. It helps define the district-scale morphology of structural networks and predict which structures may be associated with the formation of mineral deposits. Aeromagnetic data is particularly useful in guiding geologic mapping, exploration targeting, and strategy because the data available is usually broad, geologic processes and features are normally well imaged in the data, and it is relatively cheap to acquire and process. A foundation to the interpretation of the geophysical data is that the interpreter should be a geoscientist familiar with the geology of the area in question, maximizing the integration of geologic knowledge of the area into the interpretation product. The interpreter must think geologically when building the interpretation, drawing on the parallels between aeromagnetic interpretation and geologic mapping/air photo interpretation. Geologic mapping observations have direct parallels in aeromagnetic interpretation (e.g., lithology, structure, alteration). The interpretation process is outlined using the Lake Lefroy region, Western Australia, including form line construction, identification of magnetic rock units, domain definition, data set integration, definition of structural elements, lithological definition, interpretation of the structural framework, and evaluation of the interpretation. Case studies are then provided at a range of scales from the Pine Creek inlier in northern Australia, the Superior province in eastern Canada, and the Zambian Copperbelt Northwest province to illustrate the connection between the interpretations and exploration targeting. The final integrated interpretation is a supplement to outcrop maps, not a competitor. The purpose is to generate a structural and lithological framework that combines the geophysical data of different types with the mapped geology, which can be interrogated by mineralization models over a much wider area than can be achieved if structural elements and lithology are restricted to areas of outcrop.

Abstract Aeromagnetic surveys became an integral part of gold exploration programs in the Archean Yilgarn block, Western Australia, during the mid-1980s. Although previously accepted in regional geologic mapping and in exploration for magnetite-associated deposits, aeromagnetics has gained in stature as a primary gold exploration tool through its capacity to portray subtle geologic detail over a wide range of scales. Two developments in the application of aeromagnetics have been largely responsible for highlighting geologic elements pertinent to the localization of gold mineralization. The first is the introduction of image-processing techniques which permit display of a much wider range of information than conventional contours, and when applied to aeromagnetics, provide much greater flexibility in highlighting particular aspects of the data. The other major development has been the introduction of multiclient surveys, in which detailed, nonexclusive data are gathered over large areas and become available to explorers at a much reduced cost. Such data cater to both regional area selection studies and prospect-scale geologic mapping. The extended geologic resolution of aeromagnetic data is illustrated in three examples from the Kalgoorlie region in the Eastern Goldfields province of the Yilgarn block.