A rockin’ Metro Tunnel relic for the archives

You don’t need to be a rockhound to appreciate the latest addition to the State Library of Victoria’s collection of historical artefacts.

The Metro Tunnel Project has gifted the library an excavated rock from its State Library Station site, 42 metres below ground – the deepest point of excavation across the entire project.

The piece of Melbourne bedrock has been added to the State Library of Victoria’s Realia Collection, which already includes a range of historical artefacts related to Melbourne’s infrastructure and transport system.    

While it might look typical, Metro Tunnel’s manager for State Library Station Stefania Calati said the rock was far from ordinary.

This humble rock is much more than meets the eye – it’s not only from the deepest part of the Metro Tunnel Project, but it also represents the enormous amount of work that is going into making the project a reality.

“We’re very excited to gift this rock to State Library Victoria, so it can become part of a special collection of historical Melbourne artefacts that Victorians can view for generations to come.”

The State Library Station site is surrounded by bedrock that is several kilometres thick – known to geologists as “Melbourne Formation”.

Melbourne Formation is mostly made up of siltstone. However, at State Library Station excavators had to dig through three different layers of rock – siltstone, sandstone and other rock types such as dyke.

The rock will serve as a piece of Melbourne’s construction history and a reminder of one of Victoria’s most significant engineering feats – the Metro Tunnel Project.

“The construction of the Metro Tunnel will go down in history for changing the face of Melbourne, much like the building of State Library Victoria almost 170 years ago,” State Library of Victoria CEO Paul Duldig said. “As collectors of Victoria’s social history, the rock is certainly something we are keen to hold so the story can be told for years to come.”

The rock will be available on request for anyone to see at the State Library.

State Library Station is one of five new underground stations being built as part of the Metro Tunnel Project – and one of two new CBD stations. The station will be a northern gateway to the city, with entrances on Franklin St and Swanston St and a direct underground connection to Melbourne Central so passengers can easily switch between Metro Tunnel and City Loop services. •