Later Cainozoic deposits, evidently accumulated in lakes, and sometimes ferruginous, may be referred to the Miocene. They are comparable in age with the Janjukian marine beds of Spring Creek and Waurn Ponds in Victoria. These occur far inland and occupy distinct basins, as at the Wannon, Bacchus Marsh (Maddingley), and Pitfield Plains. Leaf-beds of this age occur also on the Otway coast, Victoria, containing the genera Coprosmaephyllum, Persoonia and Phyllocladus. In all probability the Dalton and Gunning leaf-beds of New South Wales belong here. Examples of the genera found in beds of this age are Eucalyptus (a species near E. amygdalina), Banksia or Native Honeysuckle, Cinnamomum or Cinnamon, Laurus or Laurel, and Fagus (Notofagus) or Beech ([Fig. 61]). In the leaf-beds covered by the older basalt on the Dargo High Plains, Gippsland, leaves of the Ginkgo Murrayana occur.
In South Australia several occurrences of leaf beds have been recorded, containing similar species to those found in the Cainozoic of Dalton and Vegetable Creek, New South Wales. For example, Magnolia Brownii occurs at Lake Frome, Bombax Sturtii and Eucalyptus Mitchelli at Elizabeth River, and Apocynophyllum Mackinlayi at Arcoona.
Fruits of the “Deep Leads.”—
The Deep Leads of Victoria, New South Wales and Tasmania probably begin to date from the period just named, for they seem to be contemporaneous with the “Older Gold Drift” of Victoria; a deposit sometimes containing a marine fauna of Janjukian age. This upland river system persisted into Lower Pliocene times, and their buried silts yield many fruits, of types not now found in Australia, such as Platycoila, Penteune and Pleioclinis, along with Cupressus (Spondylostrobus) and Eucalyptus of the existing flora ([Fig. 62]).
Pleistocene Plants.—
The Pleistocene volcanic tuffs of Mount Gambier have been shown to contain fronds of the living Pteris (Pteridium) aquilina or Bracken fern, and a Banksia in every way comparable with B. marginata, a species of the Native Honeysuckle still living in the same district.
Fig. 62—Leaves of a Fossil Eucalyptus. (E. pluti, McCoy).
About 3/4 nat. size. From the Cainozoic Deep Leads, Daylesford, Victoria.
(Nat. Mus. Coll.)