The colluvial slopes around Ararat originate from the hills and rises of Cambro-Ordovician marine siltstone, although some colluvial slopes are of granite origin. Brown Sodosols are the common soil type for the colluvial slopes of both parent materials. As the soils are quite dispersive, they are prone to water erosion when land use practices exceed land capability.
Plate 3 Colluvial slopes of the Ararat Granodiorite near Maroona with a southeasterly
aspect.