ABSTRACT
Early and Middle Palaeozoic rocks of the Lachlan Fold Belt underlie the entire Melbourne Region. Most of the Melbourne Region is underlain by the Siluro-Devonian marine sediments of the Melbourne Trough. Within the Melbourne Region, Permian rocks outcrop only in the Bacchus Marsh area. Extensive basaltic volcanism covered much of the Melbourne district and areas to the north and west of the city during the Quaternary. Ordovician marine sedimentary rocks outcrop widely in central and eastern Victoria and, within the Melbourne Region, form the basement of the western portion of the area and part of the Mornington Peninsula. Different stratigraphical terminology has been devised for both the northern Port Phillip Basin and the Mornington areas although reviews have attempted to standardise some terminology. Aerially extensive sheets of Cenozoic sediments and basaltic volcanics cover some 40% of the Melbourne Region and surficial Quaternary sediments complete the geological complexity of the region.
