Mapping of the Winnininnie 1:63,360 mapsheet has been undertaken as part of a programme to complete mapping of the Olary 1:250,000 Sheet. The area lies about 200 miles from Adelaide on the road and railway line to Broken Hill, and includes the township of Manna Hill. This report is a progress report written because of a transfer in employment of the writer. About 15 per cent of the sheet remains to be mapped. This unmapped area includes all rocks of the Archaean granitic and metamorphic basement complex. Most of the mapped area is covered by a conformable sequence of sediments of the Wilpena and Umberatana Groups of Proterozoic age. The Wilpena Group comprises siltstones and shales with interbedded limestones, and has a thickness of about 6,000 feet. The bounding upper and lower tillites of the underlying Umberatana Group are separated by a sequence comprised mainly of siltstones. This monotonous sequence is about 12,000 feet thick. Detailed mapping of the Pepuarta Tillite and associated sediments suggests that the boundary between the Wilpena and Umberatana Groups should be placed below an impersistent grey quartzite unit which contains interbedded dolomites, or at the base of the Ulupa Siltstone when the quartzites are absent.