The Mittagong Formation is a type of sedimentary rock

Sedimentary rock

Sedimentary rock are types of rock that are formed by the deposition of material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles to settle and accumulate or minerals to precipitate from a solution....

 occurring in the Sydney Basin

Sydney Basin

The Sydney Basin is a sedimentary basin on the east coast of New South Wales, Australia consisting of Permian and Triassic sedimentary rocks...

 in eastern Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

. Formed in the triassic

Triassic

The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...

 period. It may be seen as a narrow band of fine grained sandstone

Sandstone

Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

 between the shale

Wianamatta shale

Wianamatta Shale is the uppermost outcropping unit in the Sydney Basin in New South Wales, Australia. It dates from the Triassic Period and generally comprises fine grained sedimentary rocks such as shales and laminites with less common sandstone units...

 (above) and the Hawkesbury sandstone (below). The maximum thickness is ten metres.

In northern Sydney

Sydney

Sydney is the most populous city in Australia and the state capital of New South Wales. Sydney is located on Australia's south-east coast of the Tasman Sea. As of June 2010, the greater metropolitan area had an approximate population of 4.6 million people...

 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

Critically endangered

Version 2010.3 of the IUCN Red List of Threatened Species identified 3744 Critically Endangered species, subspecies and varieties, stocks and subpopulations.Critically Endangered by kingdom:*1993 Animalia*2 Fungi*1745 Plantae*4 Protista-References:...

 Sydney Turpentine-Ironbark Forest

Sydney Turpentine-Ironbark Forest

The Sydney Turpentine-Ironbark Forest is one of six main indigenous forest communities of Sydney, New South Wales, Australia. It is also among the three of these plant communities which have been classified as Endangered, under the New South Wales government's Threatened Species Conservation Act...

.