Four areas on the south-western margin of the Palaeo-Mesoproterozoic Willyama Inliers were mapped in detail to elucidate the nature of their lithostratigraphy, structure and mineralisation. These basement inliers are composed of metasedimentary/metavolcanic lithostratigraphic units of the ~1715 Ma Wiperaminga and Ethiudna Subgroups, intruded by igneous complexes of the ~1715-1710 Ma Basso Suite, ~1685 Ma Lady Louise Suite and ~1590 Ma Bimbowrie Supersuite. Younger metadolerite dykes, with interpreted intrusive ages ranging from penecontemporaneous with the ~827 Ma Gairdner Dyke Swarm to younger than Cambrian, were also found within the basement units. The basement rocks appear to have undergone four Olarian and two Delamerian deformations. OD1 is preserved as a layer sub-parallel schistosity, and in one location as an interpreted D1 shear zone. Overprinting relationships between recumbent OF2 and upright OF3 folds have produced both type 2 (non-coaxial) and type 3 (coaxial) fold interference patterns. The proximal occurrence of type 2 and type 3 interference patterns developed through the same overprinting fold events (OF2 and OF3) implies the development of sheath-like structures. OD4 had only minor effect on basement, with deformation predominantly being expressed as minor warping and the development of east-west trending shear zones. Complex interaction between basement inliers and Neoproterozoic cover sequences from ~850 to ~480 Ma has resulted in the current inlier outcrop geometry. The eastern margins to basement inliers are typically steep easterly dipping unconformities, formed both by the gradual down-dip rotation of half-graben structures along listric fault surfaces, and the progressive formation of localised roll-over antiforms during cover sequence sedimentation. The western margins of inliers are both steeply faulted and unconformable, with their current attitude resulting from compressional reactivation along original extensional fault surfaces. Metallic mineral prospects found within the mapping area are primarily quartz-vein and shear-hosted epigenetic copper deposits, yielding mineralisation and/or remobilisation ages considered analogous to previous workers' results of 480-450 Ma. The shallow depth of mine shafts and drives, and the predominance of oxidised ore in relic surface stockpiles, indicate that historical mining had targeted oxidised and supergene-enriched ore zones. Mapping has uncovered previously unreported base and precious metal mineralisation in mafic intrusive bodies, including 2% Cu and anomalous Au from previously unmapped ~1700 Ma metabasalt bodies.