Age: 430 million years, Mid Silurian
Location: Central Canberra
Formation: This limestone formed in warm, shallow, tropical seas when Australia was part of the Gondwana supercontinent. It contains occasional fragments of coral and shell.
Significance: Outcrops of this rock along the Molonglo River gave the Canberra region its early European name of ‘Limestone Plains’. Most of these limestone outcrops are now covered by the waters of Lake Burley Griffin. Subsurface beds of limestone, and associated caves, caused engineering problems for the foundations of many Canberra buildings.
Donated by: The Government of the Australian Capital Territory and the Department of Defence.