Reviews location, objective method of work, previous work (geological and geophysical). Estimated maximum thicknesses is 7,650 to base of Knight Group. Stratigraphy is as follows: Palaeozoic - Igneous rocks. No outcrop.> Permian - may occur N. of Kingston and near Coleraine (Victoria). Mesozoic - No outcrop, but known in Robe (1,475) and Comaum Bores. Merino Group outcrops occur in Casterton-Coleraine area (Victoria). Tertiary - Knight Group occurs at surface or below alluvium at 4 localities (see map Plate 1). It is 965 thick at Robe. Gambier Limestone is bryozoal, up to 800' thick SW of Mount Gambier. Pleistocene - Dunes etc. Structure is as follows:> Graben through Penola-Robe area; horst through Mount Gambier; graben S. of Mount Gambier; basement appears to rise towards Port MacDonnell. This faulting appears to be pre-Tertiary. Recent faulting is mainly en- echelon, trending northwest with a north block upthrown of a few hundred feet or less. Folding occurs W. of Mount Schank and Tantanoola.