Revised Oligo-Miocene stratigraphy of the Murray Basin, southeast Australia

Abstract

This paper reconciles the outcrop and subsurface Oligo-Miocene marine stratigraphy of the Murray Basin to arrive at a basin-wide correlation. The initial open-marine transgressive marl and clay facies of the basin belong to the Ettrick Formation, a unit that is also laterally equivalent to the calcisiltite and calcarenite that are present on the surface and in the subsurface in the basin. Since this unit is lithologically indistinguishable from the previously identified Victorian Oligocene to Middle Miocene Winnambool Formation, we suggest that the latter unit be replaced as a stratigraphic unit in the basin. The majority of outcropping units in South Australia can be recognised lithostratig..