The Milang one-mile Military sheet is defined by latitudes 35°15’ and 35°30’ and by longitudes 138°30’ and 139°00’. It is situated south of Adelaide, on Fleurieu Peninsula and comprises mainly parts of the counties of Adelaide and Hindmarsh. The principal townships are Strathalbyn, Willunga, Goolwa, Milang and Mt. Compass. The area includes a range of hills which is the continuation, to the south, of the Mt. Lofty Ranges. It is bordered by two plains. To the north are the Willunga Plains. To the southeast, and covering nearly half the area of the military sheet, are the Milang plains, which are a marginal extension of the Murray basin plains. From the east, the approach to the hills is fairly smooth. On the western side, however, the edge of the ranges is limited abruptly by the Willunga Scarp. In the ranges the summits are broadly concordant, reaching nearly to 1400 ft. The main water courses flow southeast into the freshwater basins of Lake Alexandrina and the Goolwa of Lower Murray River. They are, from north to south the River Bremer, the Angus River, the Finniss River, the Tookayerta Creek and Currency Creek. Climatically, the region is temperate with an average annual rainfall slightly over 20 inches on the Willunga plains and slightly less on the eastern side of the ranges. In the hills the rainfall approaches 30 inches. Both plains cultivated for cereal crops and are also used for sheep pastures. The hills are only locally cultivated and provide mainly dairy cattle and sheep pastures, with some pine plantations in the the Spring Mount and Kuitpo areas. For the geological map, Horwitz carried out field work, initially under the direction of B. Campana and later under that of B.P. Webb (Senior geologists). Mapping was done during the summer seasons from 1954 to 1956. The results were described in 1958 (published 1960). In 1958, B.P. Thomson, assisted by A.R. Crawford, remapped and subdivided the Kanmantoo Group on this military sheet. Valuable field assistance was given by students of the University of Adelaide: D. Taylor, K. Mills and F.B. Pontifex. Palaeontological age determination was done by N.H. Ludbrook (senior), Palaeontologist, Geological Survey. Later petrological work was done at Parkside Laboratories by H.W. Fander in 1958. Mapping was carried out on Adastra vertical air photographs, at a scale of 4” to 1 mile. For publication, the sheet has been drawn by W. Ressini of the Map preparation section, Geological Survey, using a military base map at an approximate scale of 40 chains to the inch.