256 Scientific Proceedings, Royal Dublin Society. 



seem to be derived from the Carboniferous Slate and Old Red 

 Sandstone. 



Although the section at this point is incomplete, it is, 

 perhaps, the finest exposure of the beach-deposits on the coast 

 (see Plate XXIV.). 



Section in Ballycroneen Bay. — East of the Coast-guard Station 

 in Ballycroneen Bay, the following section can be made out : — 



Feet. 



Reddish clay and stones, . . . . 7 \ 



Fine loamy sand with stones, . . 8 



Marly boulder-clay, . . . . . . 20 



Head, . . . . . . . . 6-12 



Rolled gravel and sand, . . . . 1-2 



Platform. 



The marly boulder-clay is a tough, greenish-grey clay con- 

 taining shell fragments, and small stones of local and distant 

 origin. It is overlaid by a very fine loamy sand with numerous 

 angular and sub-angular local stones and a few rounded erratics. 

 Above this, and graduating into it, is a red, sandy boulder-clay, 

 similar to that of Cork, which, as pointed out above, has been 

 deposited by ice ooming from the west. The marly boulder-clay, 

 on the other hand, can be traced eastward into County Wexford, 

 and thence northwards to the neighbourhood of Dublin, being 

 undoubtedly the boulder-clay of the 'Irish Sea Ice.' The 

 * West Cork Ice ' seems to have advanced over ground once 

 occupied by the ' Irish Sea Ice ' ; this overlapping of the charac- 

 teristic boulder-clays of these sheets taking place along a limited 

 area near their junction. 



The section shows clearly that the beach-deposits and head 

 were formed prior to the occupation of the ground by the ' Irish 

 Sea Ice.' 



Section in Ringabetta Bay. — An extreme modification of the 

 cliff -sections arises when all the deposits are eliminated but the 

 boulder-clay. It thus comes in contact with the platform which 

 is glaciated beneath it. On the north side of Ringabella Bay 

 the platform attains a width of 40 to 60 yards, and has a remark- 

 ably level surface. The boulder-clay, which is banked against the 

 cliff behind, thins gradually seaward for a distance of 20 or 30 



