Black coal – forests form carbon deposits

Forests of tall conifer trees grew in the rift valley during the Cretaceous. These forests had an understorey of familiar-looking plants – relatives of today’s ferns and Ginkgo tree. Ginkgoites was quite common at this time; related to the modern-day tree Gingko biloba. Ferns like Cladophlebis were also abundant, providing food and shelter for small plant-eating dinosaurs.

Vast amounts of vegetation accumulated in parts of the valley, and over millions of years this plant material turned into seams of black coal. The thickest deposits were in Gippsland. The Wonthaggi coal mine produced 17 million tonnes between 1909 and 1968 – an important source of energy for Victoria.