ABSTRACT OF PROCEEDINGS. XXXIX. 



only by marine action. The lowest portions of the headland cliffs 

 themselves also exhibit the characteristic marks of subaerial 

 weathering. Many of the cliffs themselves are protected by great 

 fallen blocks which litter their bases. These are deeply pitted 

 with holes of subaerial weathering, and the greatest storm waves 

 of the past 20 or 30 years have not been observed to have moved 

 such large blocks. Many of the cliffs also are of the form known 

 as well-subdued, and are covered with forest growths, indicating 

 that effective sapping has ceased for very many years. 



Great sand flats also occur from five to twenty feet above high 

 water mark in the vicinity of the platforms. Right along the east 

 side of Australia, both these sand flats and the rock platforms 

 have been trenched deeply, the former by subaerial influences, the 

 other mainly by wave action. 



Various observers have recorded the existence of horizontal zones 

 of dead barnacle colonies in situ a few feet above the highest limit 

 of massed barnacle growths to day. These emerged features occur 

 on exposed rock faces with deep water immediately below. 



Various observers also, such as Wilkinson, David, and Harper, 

 have recorded the existence of marine "blowholes" behind the 

 platforms in positions such that they are high above the influence 

 of the greatest storms of the present time. 



All this evidence tends to demonstrate that the present shore- 

 line of eastern Australia is a feature of emergence of very recent 

 origin, probably not exceeding a few hundred years. Lady 

 Robinson's Beach, being considered merely as a type of such 

 features, appears to be also one of very recent emergence. 



It cannot be emphasised too strongly that these slight move- 

 ments of recent emergence have been imposed upon a recent but 

 much greater movement of submergence which drowned the whole 

 eastern side of Australia to the extent apparently of 200 feet. 



Many observers of the Sydney and eastern Australian shoreline 

 profess to see only the features due primarily to submergence, 

 such as bay bars, lagoons, silted water ways, and cliffed headlands. 



