This paper introduces a formal lithostratigraphic scheme for major subdivisions of the Olary Domain, and compares these subdivisions to those of the Broken Hill Domain, these two domains being the main components of the Curnamona Province. The scheme is based largely on proven effective stratal classification aspects of previous geological mapping and minerals exploration work: where possible, stratigraphic names have been retained or adapted from this work. Eleven units at formation level were proposed by the author at the May 2000, 5th Broken Hill Exploration Initiative Conference held in Broken Hill; these, together with other formations and members, will be formalised in the near future after type sections have been evaluated. One well-known unit, the 'Bimba formation', although not formally defined, is referred to in this paper. Work is in progress to formally define this lithologically variable unit and to determine the most suitable type section. Most of the group and subgroup level units discussed herein are defined with representative traverses or areas in lieu of type sections, pending publication of the definitions of constituent units.