Gravity and detailed aeromagnetic data, as summarised in the Metallic Exploration Index Series for CURNAMONA and OLARY, are interpreted. Other detailed geophysical and geological work is incorporated. The interpretation aims to define the areal extent of, and depth to, near-surface magnetic basement, to help to resolve the observed geological structures and to identify specific targets for further detailed geophysical exploration programmes. Aeromagnetic maps are subdivided into magnetic zones.