Hydrological investigations were made in conjunction with the Denison Peake Geological Survey, including the one mile Military sheets of Algebuckina, Nilpinna, Conway, Umbum, Boorthanna, Cadlareena, Anna and Delray. Here, the generally flat area of Mesozoic basin sediments of the south-west portion of the Great Artesian Basin is interrupted by north-west trending ranges of Pre-Cambrian rock. Gibber covered plains, sandhills, ridges, alternating with barren clay pans and sandstone table land, frequently ferruginous, support only sparse vegetation in this region of low rainfall. General eastward drainage to Lake Eyre is interrupted by the ranges resulting in the swamp area of Lake Conway. Basin sediments observed are Lower Marine Cretaceous shales with fossiliferous thin limestones and underlying sandstone of probable Jurassic age resting unconformably on Pre-Cambrian rock. Possible Upper and Middle Cretaceous outcrops occur at Mount Harvey in the form of porcellanite. Post-Cretaceous beds were not recognised except as wind blown sands and river and flood plain alluvium. The form of Jurassic (?) sandstone outcrops, gravity readings, bore log information and hydrological considerations indicate a Pre-Jurassic (?) sandstone basin west of the Margaret Ranges. The presence of this basin may be due, in part to glacial deepening in Permian time. Till or Tillite lying unconformably on Pre-Cambrian rock, was found on the western margin of the Margaret Ranges with no suggestion of overlying sedimentary deposits. Puzzling glaciated-like boulders of quartzite were found widely distributed on the surface of Mesozoic sediments. Good stock water is available from flowing bores and springs in the Jurassic (?) sandstone aquifer where the water is confined by overlying Cretaceous shales. Where unconfined, non-pressure waters are available in the sandstone from points below the local water table.