Conference Papers

Exploring the Coastline....

Jim Bowler

Fig. 5.

Diagrammatic representation of shore platform in dune calcarenites typical of those in the Sorrento - Nepean area of the Port Phillip region.

Ancient red soils formed during stable periods when sea level was lower, and active beaches had moved seawards. Soft calcareous sands were cemented, then subjected to weathering and soil formation.

Erosion by modem sea levels has produced two cliffs. Platform width is a function of the relative migration rates of the cliffed breaks in slope. Boulder accumulation often protects the inner cliff producing temporary stabilisation. Chemical solution etches the platform into a variety of karstic features.

Biological colonisation is controlled by the physical zonation between the inner abrasion zone and the outer chemically affected zone, often leading to a rampart zone which sometimes marks the outer platform margin.