Wright and Muff — Pre-glacial Raised Beach. 263 



Attempts to find the beach-deposits at the foot of cliffs of lime- 

 stone in Cork Harbour and on the Waterford coast were unsuc- 

 cessful. Not far from the limestone outcrop on the west side of 

 Whiting Bay, limestone pebbles, often bored by Saxieava and 

 Cliona, are common in the modern shingle. The pre-glacial beach 

 is exposed in the cliffs, but not a single limestone pebble could be 

 found in it. This seems to point to the complete decalcification 

 of the beach-deposits. 



The pre-glacial blown sand occurs buried beneath the head (see 

 Plate XXVIII.) and banked against the rock-cliff. Where not 

 cemented by iron-oxides, it is a fine, yellowish, even-grained sand. 

 It often shows bedding dipping gently away from the cliff. Con- 

 cretionary layers are not uncommon. Generally there are a few 

 thin slivers of slate lying along the bedding planes in the upper 

 layers. The matrix of the lower portion of the head is often 

 formed of it; but the line of separation of the sandy head and 

 the blown sand is fairly distinct. As it often lies on the beach- 

 deposits, not more than a foot or so above the platform, it 

 furnishes clear proof that the elevation of the beach commenced 

 before the head began to accumulate. It occurs in places lodged 

 against the cliff at a height of 35 feet above the platform. 



At the entrance to Cork Harbour, blown sands were most 

 frequently met with in the sections lying between Bingabella Bay 

 and Camden Fort. They also occur near Roche's Point, but are 

 not as abundant on the eastern side of the Harbour entrance as on 

 the western — a point worth consideration in connexion with the 

 travel of erratics in the beach (see foot-note, p. 262). 



The lower head, or rubble-drift, is found overlying the raised- 

 beach shingle and blown sand. When the latter are not present, 

 it rests directly on the platform. It consists of angular rock- 

 fragments of strictly local origin identical with the rocks forming 

 the cliff or slope against which it is banked. The cleaved slates 

 and sandstones of the Old Bed give rise to a head composed of 

 small slabs, which lie parallel to one another, and constantly dip 

 at low angles away from the cliff. Grit bands naturally afford 

 more or less cubical blocks. The soft, grey slates of the Carboni- 

 ferous Slate series produce by their decomposition a yellow loam 

 mixed with small slivers of slate. The deposit thus varies in 

 composition according to the locality, but there are also varia- 



