The vertical rock cutting is situated on the northern side of State Circle on Capital Hill between Commonwealth Avenue and Kings Avenue and is just over 300 metres in length. The Shale here is formed of mainly siltstone and very fine sandstone which has been strongly contorted by slumping. Marine fossil graptolites were found during excavation of the cutting, the most common species being Monograptus exiguous, which confirms the deposits were laid down in a deep oceanic environment, and they also help to indicate the age of the sediments. The age of these rocks has been estimated at approximately 435 million years old, which places them in the Early Silurian Period.
The State Circle Cutting is significant for its unconformity geological feature, and along with the nearby Capital Hill feature. The geological feature provides keys to the interpretation of the ancient geological landscape in the Canberra region. The place is listed by the Geological Society of Australia as being of international significance as an outstanding exposure of an important folding event. It is one of only two listed sites in the ACT.
Under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act), all Commonwealth agencies are required to prepare management plans for Commonwealth Heritage listed and nominated places under their management. The purpose of this management plan is to identify, protect and manage the heritage values of the State Circler Cutting.
This management plan was prepared in accordance with the Commonwealth Heritage management principles and the requirements under the EPBC Act.
This management plan was reviewed by the Australian Heritage Council.