The oldest rocks on WARRINA outcrop in the Peake and Denison Inliers, which comprise the Davenport and Denison Ranges and small inliers to the east. Basement in this area consists of Palaeoproterozoic metamorphic rocks which were intruded by Palaeoproterozoic granite and Mesoproterozoic basic dykes. The bulk of the Peake and Denison Inliers is formed of a very thick sequence of Neoproterozoic (Adelaidean) sediments and minor basic volcanics deposited in a northern extension of the Adelaide Geosyncline. The Adelaidean rocks have been intruded by Early Palaeozoic (Delamerian) intermediate and basic igneous rocks, plus diapiric breccias. Rocks of interpreted Adelaidean and Palaeoproterozoic ages have been recorded in the subsurface east and west of the Peake and Denison Inliers. Sediments of ?Neoproterozoic, Cambrian and possible Devonian ages were deposited in the Boorthanna Trough west of the Peake and Denison Inliers, and Early Palaeozoic sediments of the Warburton Basin are inferred to exist in the subsurface in the north-eastern corner of WARRINA. In Early Permian time the Boorthanna Trough was part of the extensive Arckaringa Basin, which contains a sequence of glacio-marine, marine and fluvio-lacustrine deposits. Small outcrops of Early Permian sediments occur along the western margin of the Peake and Denison Inliers. Latest Jurassic to Early Cretaceous sediments of the Eromanga Basin outcrop extensively throughout the area surrounding the ranges, and rest on a remnant of a peneplain of interpreted Late Permian to Early Jurassic age within the Davenport Range. Limited exposures of Tertiary sediments and silcrete east of the Peake and Denison Inliers mark the western limit of the Lake Eyre Basin. Other Tertiary deposits include terminal sequences of the Mirackina Palaeochannel, and local occurrences of lacustrine carbonate. Widespread Quaternary units include fluvial channel, fan and floodplain deposits, colluvial deposits, gypsite, aeolian dune sands, claypan deposits and local mound spring deposits.