In addition to the sand and gravel that makes up the ubiquitous concrete structures, our cities are built from an exciting variety of geological material. In Brisbane these range from the warm brown sandstone of iconic structures such as the City Hall and Parliament House to granites and exotic marbles from around the world.
The Queensland Division of the Geological Society of Australia chronicled these fascinating materials as a self-guided walking tour for the International Geological Congress in 2012.
The tour has recently been extended and built into a mobile App that will be available to the public in time for G20. The app presents a GPS linked map with hot-links to the history of each building and details of the building stones used along with both recent and historical photographs.