The Metro Tunnel Project has donated a piece of ancient rock to State Library Victoria, to be housed in its public collections.
The rock is from the deepest point of excavation on the major transport project, from 42 metres below Swanston Street at the site of the future State Library Station.
The site is surrounded by bedrock that is several kilometres thick and is known to geologists as Melbourne Formation. This sedimentary rock covers the Silurian geologic period of 443 million to 416 million years.
The donated piece of Melbourne Formation will be added to the library's Realia collection, which includes a range of historical artefacts related to he city's infrastructure and transport system.
State Library Station is one of 5 underground stations being built as part of the Metro Tunnel Project, opening to the public in 2025.
Four of the 5 Metro Tunnel stations – between Arden in North Melbourne and the Yarra River – lie within the Melbourne Formation.