270 Scientific Proceedings, Royal Dublin Society. 



The sub-angular and rounded boulders of the harder rocks are 

 generally striated. In many sections it has the structure of a 

 typical till ; in others it is rubbly on account of the working up 

 of the head into it. 



Around Baltimore it is a greenish-grey clay, containing 

 numerous boulders of green and purple slate and grit. The 

 striae and the aspect of the crags show that the ice travelled from 

 N.N.W. to S.S.E. In Clonakilty and Oourtmacsherry Bays, it is 

 a grey or yellowish-grey clay, containing abundant Carboniferous 

 slate and sandstone with a small admixture of Old Red Sandstone 

 pebbles. The boulder-clay is in fact made up almost entirely 

 from the Carboniferous Slate series, and it is significant that 

 these rocks occupy a large area to the north and west of the 

 bays, whilst the Old Eed Sandstone outcrops are of comparatively 

 small extent. In the neighbourhood of Cork Harbour, where the 

 hills are formed largely of Old Red Sandstone, the boulder-clay is 

 more sandy and of a reddish colour. 



It has been mentioned previously that in Ballycroneen Bay and 

 along the coast to the east, a red boulder-clay overlies the marly 

 boulder-clay. As might be expected, the former contains a few 

 erratics derived from the latter. One or two pebbles of flint and 

 igneous rock have been found in the boulder-clay between Bally- 

 croneen Bay and Cork Harbour. At one place in White Bay 

 the boulder-clay rests on the raised-shore platform, and contains 

 a number of rolled ellipsoidal pebbles such as are common in the 

 raised-beach gravels. Two of these were of igneous rocks, and 

 were doubtless derived from the pre-glacial beach. 



The boulder-clay of the inland-ice in the gorge of the Black- 

 water above Youghal overlies striae running N. 50° W. to S. 50° E. 

 In Whiting Bay it overlies the marl, and contains some limestone 

 in addition to Old Eed Sandstone, which is the predominant con- 

 stituent as far as Dungarvan. Here we begin to get an admixture 

 of Silurian rocks ; and from Stradbally westwards, the stones in 

 the boulder-clay are chiefly ' felstones ' and other local rocks. At 

 Ballymadder Point the boulder-clay is composed chiefly of the 

 local rocks, but also contains large blocks of the Leinster granite. 

 At Carnsore Point there is a local granitic boulder-clay with 

 flints and pebbles of schist overlying a glaciated surface of granite 

 with striae running N. 10° E. to S. 10° W. 



