120 G. H. HALLIGAN. 



THE PHYSIOGRAPHY OP BOTANY BAY. 

 By G. H. Halligan, f.g.s. 



With Plates V, VI. 



[Read before the Royal Society of N. 8. Wales, Auqust 6, 1913.] 



In the many valuable papers that have been written of 

 late years upon the physiography of New South Wales, the 

 subject has been treated entirely from the geologist's 

 standpoint. The earth movements that have undoubtedly 

 taken place nave had assigned to them their proper geo- 

 logical age; the vertical displacement of the strata, the 

 effect of the movements upon the direction of the flow of 

 rivers, and the formation of lakes and lagoons consequent 

 upou the folding, faulting and crushing have also been 

 discussed. Though much has been done, it is perhaps 

 needless to say that much remains to be done, but with the 

 enthusiastic band of workers now in the field, we may con- 

 fidently look for a continuation of the good work in the 

 future. 



It is proposed in this paper to deal with that part of the 

 subject which refers to changes in the shore line which 

 have necessarily taken place strictly within Pleistocene 

 and recent times; changes which must be taken into serious 

 consideration by the engineer, as well as the geologist, fpr 

 it is by a discussion of them that he is enabled to design 

 works in the carrying out of which he will be assisted by 

 nature, and so save the time and money for which he is 

 responsible. 



Although this paper is called the physiography of Botany 

 Bay, the principles involved may be taken to apply to many 

 other places along the 600 miles of coast from Point Danger 

 to Gabo Island. Botany Bay has been selected because 



