OFR 151.pdf - CRC LEME

It is noted that the climatic response classification developed by Nix (1991) has proved useful
in classifying some Eocene and younger rainforest communities at sites where moisture
availability is not limiting (Greenwood 1994, Macphail et al. 1994). How relevant modern
communities are as analogues for other Cretaceous and Tertiary communities is less clear
given that southern Australia was at high to polar latitudes (>60 ° S) and therefore subject to
prolonged darkness during winter months. For this reason, categorising past plant
communities in terms of the highly detailed classifications developed for the modern
Australian vegetation, e.g. Specht (1970), is considered premature unless supported by plant
macrofossil evidence.
Much of the palaeobotanical evidence of Cretaceous and Tertiary climates in Australia come
from continental margin basins in southern Australia, in particular the Bass, Gippsland and
Otway Basins in the south-east, and epicontinental basins that were inundated by marine
transgression during the Early Cretaceous, e.g. the Perth, Eromanga and Surat Basins, or
during the Late Tertiary, e.g. the Eucla and southern Murray Basins (Figure 3). A surprising
number of onshore depositional environments are due to uncommon events. Examples
include meteor craters, e.g. at Goats Paddock in the Kimberley region and Yallalie near Perth,
and lakes dammed by Tertiary tectonism or volcanism on the Eastern Highlands.
Figure 3: Epicontinental and continental margin basins (from Palyfreyman 1984)
2.4.1 Palaeovegetation
The relationship between plant fossil assemblages and the parent or source vegetation is
spatially complex and variable in time (Birks and Birks 1980, Macphail et al. 1994, Chaloner
and McElwain 1997). Three important caveats are:
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