Australia: The Land Where Time Began

A biography of the Australian continent 

Spongolite

A sedimentary rock composed largely of siliceous sponge spicules. The spicules are silica needles that form the 'skeleton' of the sponges, allowing the otherwise formless sponges to maintain a constant shape. These sponges flourished in the warm Eocene seas. They formed vast monocultures in these seas, like forests on the seabeds.

Sources & Further reading

Mary E White, After the Greening, The Browning of Australia, Kangaroo Press, 1994