Mittagong formation

The Mittagong Formation is a type of sedimentary rock occurring in the Sydney Basin in eastern Australia. Formed in the Triassic Period. It may be seen as a narrow band of fine grained sandstone between the Ashfield Shale (above) and the Hawkesbury sandstone (below). The maximum thickness is ten metres. Near Town Hall railway station, the formation is 8 metres thick.

In northern Sydney it can be seen in a few areas, such as West Pymble and Mount Ku-ring-gai. This rock formation is associated with the critically endangered Sydney Turpentine-Ironbark Forest.