OFR 151.pdf - CRC LEME

5.4 Time Slice K-1. Berriasian-Barremian [141-115 Ma]
5.4.1 Palaeogeography
Figure 4: Valanginian (133 Ma) palaeogeography (from Veevers et al. 1991)
The early Early Cretaceous palaeogeography of Australia is summarised in Struckmeyer and
Totterdell (1990), Veevers et al. (1991) and Taylor (1994). Seafloor spreading had
commenced on the palaeo-northwestern margin and progressed clockwise around the
continent (Figure 4) although at the beginning of the Berriasian, Australia was still attached
to: Antarctica to the south; New Zealand, the Lord Howe Rise-Campbell Plateau and the
Queensland Plateau to the east; and parts of Greater India to the west. One arm of the Neo-
Tethys Ocean extended along the palaeo-northern margin past the Exmouth Plateau to a point
southeast of Perth and another arm extended to the palaeo north-east. The Carnarvon region
of Western Australia formed the palaeo-northern margin, and northeastern New South Wales
the palaeo-southern margin, of the continent. By the end of the Barremian, the East Coast of
New South Wales was at a palaeolatitudes of about 80 0 S due to rotation of the continent about
the geographic South Pole whilst the Carnarvon Basin remained part of the palaeo-northern
margin of continent at a latitude of about 53 0 S.
Rifting of the Indian sub-continent from Australia was marked by subsidence in the Perth and
Carnarvon Basins and uplift of adjacent coastal regions. A large lake (Lake Murta) developed
in the Eromanga Basin as the result of this internal drainage. Cratonic blocks such as the
Yilgarn-Pilbara, Kimberley and Arunta Blocks, which had been prominent landscape
elements for much of the Phanerozoic, became important sediment sources for the
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