ABSTRACT
The Fyansford Formation is a Tertiary marine sedimentary unit of late Oligocene to middle Miocene age. In the deepest part of the Port Philip Basin, bryozoal limestone and calcareous sand of the Fyansford Formation were marginal deposits in a late Oligocene marine transgression. The Miocene marine transgression caused deposition of Sherwood Marl sediment equivalent to he Fyansford Formation from the southwest and possibly also from the west across lower parts of the Mornington Peninsula ridge. The stratigraphic contact between the Black Rock Sandstone of the Brighton Group and the Fyansford Formation is commonly marked by a bed of phosphatic and calcareous nodules. Near Geelong at the Western Beach, silty clay marl of the Fyansford Formation is overlain by the Moorabool Viaduct Sand. The Fyansford Formation type section is exposed in an outcrop at Inverleigh Road, Fyansford, near Geelong. The Fyansford Formation occurs subsurface and is represented in a number of bores.
