Geography & geology

geography geology

Ku-ring-gai is located on the Hornsby Plateau between Hornsby and Chatswood, around 14 kilometres north of Sydney.

The area is defined by four main ridges topped by Wianamatta Shale in the Hawkesbury formation, and features a diverse range of habitats, including forests, woodland, heathland, rock faces, mangroves, streams and ponds.

Sandstone and shale are the most common geology types in the area, but there is also estuarine sediment at Lane Cover River and remnants of volcanic breccia at Brown’s Field.

Ku-ring-gai’s landscapes range from closed tall forest to low open heathland, along with sclerophyllous woodland, wet heath, rainforest and mesic forest. Aquatic habitats include freshwater streams and mangrove forest, such as the stand near Roseville Bridge in Middle Harbour, and freshwater streams teeming with wildlife, such as Cowan Creek in St Ives.

Soils & geology types





Quarternary (up to two million years ago)


Artificial fill

Disturbed terrain


Estuarine settlements

Lane Cove


River sediments

Lane Cove

Triassic (2 – 64 million years ago)

Wianamatta group (Ashfield shale)

Shales, claystones and sandstone


Mittagong formation

Shale, sandstone

West Pennant Hills

Hawkesbury sandstone

Medium to coarse sandstone minor shale


Jurassic (144 – 170 million years ago)

Volcanic breccia and basalt

Structured loams and podzolic soils


Source: Sydney 1:100000 Soil Map, Soil Conservation Service

Related documents

Ku-ring-gai Brown's Field Diatreme (pdf. 2MB)

Geology of Ku-ring-gai (pdf. 3MB)

Ku-ring-gai Soil Landscapes Information (pdf. 40MB)

More info

Contact our Biodiversity Officer on 9424 0000 or