The Glass House Mountains are 45 miles (70 km) north of Brisbane. The
volcanic field consists of eroded volcanic plugs made of trachyte and
rhyolite. The volcanoes were active 25-27 million years ago. This photo
shows the rhyolite peaks of Mt. Tunbubudla volcano. All photos courtesy of
Gary Lewis of the AGSO's Geoscience Awareness Unit program.
Mt. Tibrogargan, a rhyolite plug.
Coonowrin, a rhyolite spine.
Sources of Information:
Sutherland, L., 1995, The Volcanic Earth: Sydney, University of New South
Wales Press, 248 p.
