53 
RIVER TERRACES OF THE MARIBYRNONG RIVER, VICTORIA 
We have endeavoured in this contribution 
(i) to determine the sequence of flood plains and terraces formed 
in the Maribyrnong Eiver valley since the extrusion of the Keilor 
Plains basaltic lava on which the valley was formed. The Keilor 
Flood Plain is the flnal manifestation of the Keilor cycle of 
erosion — the first cycle on the Keilor Plains lava field. It was 
followed by two cycles of erosion — the Braybrook and Maribyrnong 
Cycles, and 
(ii) to tie up these flood plains and terraces with the last post 
glacial 15 to 20 feet eustatic fall of sea level. Evidence of this 
rise is seen (Fig. 1) in the Yarra Delta, and on the shores of 
FIG. 1. 
Map showing the Maribyrnong valley between Dry Creek 
and Port Phillip Bay. 
