Abstract
Some recent models of the history of the east Australian continental margin suggest that the continental drainage divide has migrated to the west during the Cainozoic, whereas other models suggest a stable divide. All recent models of the history of the highlands (as distinct from the margin) imply a stable divide. Detailed data from Cainozoic channels in the proximal and distal reaches of the Lachlan and Wollondilly Rivers indicate divide stability in their proximal reaches for much of the Cainozoic, and at least throughout the Neogene in their distal reaches. Models of Tasman Sea formation, therefore, must incorporate a relatively stable Australian hinterland.