Rocks in Symonston are from the
Silurian age Mount Painter Volcanics dark grey to green grey dacitic
tuff underlies most of Symonston. Narrabundah
Ashstone Member is found in the northern corner near the motor park. Canberra Formation, calcareous
shale found to the east of the ashstone. Further to the east and over to Harman is found the dacitic
andesite of the Ainslie Volcanics. An unnamed coarse
leucogranite has a small out crop east of Jerrabomberra creek.
Geoscience Australia is the Australian Government organisation tasked with supplying scientific information and knowledge about the geography and
geology of Australia. It has information about the geology of the whole of Australia including Canberra. in Symonston ==Education==