SHORELINE STUDIES AT BOTANY BAY. 165 



SHORELINE STUDIES AT BOTANY BAY. 

 By E. O. Andrews, b.a., f.g.s. 



With Plates V, VI. 



[Bead before the Royal Society of N. S. Wales, September 6, 1916.'] 



The writer has had one special shoreline under observation, 

 namely, Lady Robinson's Beach, Sydney, New South Wales, 

 during the past seven years, and it has seemed advisable to 

 epitomise the main facts there noted during that period. 

 The observations made from 1909 to 1912 inclusive, have 

 been recorded 1 elsewhere. 



The Beach— The summary of the observations over the 

 whole period (1909-1916) may be presented here. The 

 littoral zone under consideration is a bay, and not an ocean, 

 type. 2 It is between four and five miles in length; its 

 disposition is almost north and south; and it is sub-parallel 

 to the neighbouring ocean shoreline. A line midway 

 between Botany Heads and drawn at right angles to the 

 general trend of the main coastline, would bisect Lady 

 Robinson's Beach approximately. The heads are a mile 

 apart, and they lie about six miles east of the centre of the 

 subject beach. The bay is shallow with a greatest depth 

 of one hundred feet approximately between the heads. 



The beach terminates against George's River on the 

 south and Cook's River on the north. In recent time these 

 two streams discharged as one into the sea, but the lower 

 portions of their valleys have been drowned to the amount 

 of 200 feet, approximately, and the bay has been formed 

 by this submergence. 



1 Andrews, E. C, Beach Formations at Botany Bay. This Journal, 

 Vol. xlvi, 1912, pp. 158-185. 



2 Andrews, E. C„ op. cit. See map accompanying paper. 



