XXXV111. ABSTRACT OF PROCEEDINGS. 



1. The fact that marine erosion on a headland consisted in the 

 first place, of a direct attack of the storm wave unarmed or armed r 

 with rock fragments, and in the second place, of the scouring 

 action of the rock load below and beyond the direct wave attack. 

 This action produced a simple profile in ordinary rock structures, 

 steeper near the land and flattening gradually towards the sea. 



2. The topography of Lady Robinson's Beach and the land 

 surface immediately behind the beach were due, apparently, to two 

 activities, the one not coming into operation until the completion 

 of the other. Thus the broad rolling surface of sand covered by 

 forest growths, subhorizontal when viewed from above, and rising 

 about fifteen feet above high water mark was explained as an 

 emergent feature, whereas the overlying belt of sand dunes" behind 

 the beach was due to the later action of the wind. 



3. The fact that along the whole south-eastern and eastern side 

 of Australia rock platforms and lines or zones of marine erosion 

 occur at and above high-water mark. 



These rock platforms have been formed by marine erosion. They 

 may be wide or narrow, they may occur in rock masses of igneous 

 origin or in those possessing gentle dips, or they may occur in 

 rocks showing strong contortion. The platforms, however, in 

 nearly every instance transgress the bedding planes. 



The surfaces of the platforms lie but a few feet above high water 

 mark, but they may occur one above the other, separated by low 

 escarpments. 



The main attack of the storm waves to day appears to be. on 

 the edge of the lowest platform, in the cases where more than one 

 exists, and there is thus evidence of two or more lines or zones of 

 marine cutting vertically above the other. This in itself is in 

 direct contradistinction to the idea that the sea has cut the plat- 

 forms at the same time, inasmuch as the tendency of the sea wave 

 is to establish a simple profile of erosion on a stable shore line. 



The surfaces of the platforms themselves are deeply pitted and 

 scored with holes, due to subaerial action, aided in a minor degree 



