ABSTRACT
The development of engineering structures in the Melbourne District confronts significant problems as well as costs related to groundwater inflow and corrosivity deriving therefrom. The Silurian aged sandstone, mudstones, siltstones and shales form the predominant bedrock material beneath Melbourne. The Silurian formations have undergone alteration due to thermal metamorphism adjacent to granites and granodiorites and other changes along some important structural lines. The Werribee Formation only occurs in a few places around the Melbourne district at depths to which civil engineering structures may extend. The Older Volcanics occur within the basal sediments of the Tertiary in the Melbourne District. To the south west of Melbourne, excluding south to beyond Werribee, the Fyansford Formation is not an aquifer, but is the aquitard separating the confined Werribee Formation from the more or less unconfined upper aquifers including the Brighton Group and Newer Volcanics.
