Geophysical 1D/2.5D forward and inverse modelling was performed on the EM data from airborne electromagnetic (AEM) TEMPEST surveys conducted in the Cariewerloo, Tarcoola and Frome Embayment regions and from a VTEM survey flown in northern Eyre Peninsula (at Paris prospect). The Tarcoola and Paris data responded well to 2.5D inversions, with the Paris TEMPEST data displaying reasonable consistency between the measured X and Z components, allowing the inversion to resolve more complex 2D structure and to extend the predicted geology deeper in section. These outcomes support the driving notion that reprocessing of older AEM data can extract benefit at little extra cost. The TEMPEST data from Cariewerloo and Frome are relatively noisy, leading to the conclusion that original QC testing did not identify noise issues in their X and Z components. A workaround, involving re-scaling the Z component of the Frome data, yielded acceptable results. Reprocessing of the South Australian subset of the national gravity map was also performed, via anisotropic clustering and 3D fault network generation. Full Tensor Analysis and an extended 3D worming method were used for geological dip determination from full tensor gravity gradiometry (FTG). Dips were determined automatically on 98 candidate faults. However, this reprocessing of State-wide gravity data derived from the national grid has demonstrated that the full tensor analysis requires higher standard, industry quality data, and that merged national database gravity inputs are not of sufficient quality to provide useable FTG products.