SHORELINE STUDIES AT BOTANY BAY. 



169 



The building of the beach behind the limit of the wave 

 of normal weather.— The great storm of July 1912, as far 

 as Lady Robinson's Beach was concerned, was really a 

 series of great ground swells, these being pulsed into Botany 

 Bay by the action of a tempest at some distance offshore. 

 During the height of the storm, when so much damage was 

 done to the beaches, the wind was actually offshore at the 

 beach under consideration. 



During this storm a cliff almost vertical and of height 

 varying from five to fourteen feet was excavated by the 

 waves in the sand dunes of the beach. 



In Fig. 1 is depicted the general appearance of the 

 southern portion of the beach in August 1916, more than 

 four years after the great gale had gone. The cliff of 

 erosion is subdued but it is easily the dominant form of the 

 beach immediately seawards of the higher points of the 

 sand dunes. 



B C D = Terrace of accumulation. 



Fig. 1. — Diagrammatic representation of shoreline profiles at Rarnsgate, on 

 southern end of Lady Robinson's Beach (September, 1916). 



B B'N DC = Terrace formed beyond wave limit by blown sand and Spinifex 

 since July 1912. 



DE'E = Profile cut by 1912 storm. 



Beneath the subdued cliff (Plates V, VI, figs. 1 and 3) 

 a narrow terrace may be observed, about twelve to fifteen 

 feet wide and four to six feet above ordinary high tide. To 



