part 3] 



GLACIATION OF NORTH-EASTERN IRELAND. 



365 



With these exceptions, all the high land consists of the Tertiary 

 hasalts, which rest in some places directly upon the Dalradian 

 schists, but elsewhere are separated from them by attenuated re- 

 presentatives of the Trias, Lower Lias, and Cretaceous rocks. 



Grlendun. — The greater part of Glendun, from the Shooting 

 Lodge downwards, contains large quantities of gravelly drift, 

 although in places boulder-clay occurs. In the stream immediately 



Fig. 3. 



below the Shooting Lodge the gravels and sands are fine-grained 

 and stratified, and the} r contain abundantly schist and vein-quartz 

 with a little flint, chalk, and basalt. All these rocks could be 

 derived from the north-east. 



The gravelly drift is, for the greater part, confined to the bottom 

 and the lower slopes of the valley ; while the higher slopes, from 

 the 1000-foot contour downwards, are strewn with enormous 

 numbers of big boulders of the local schist and gneiss. 



Near the junction of Clyttaghan Burn with the Glendun River, 

 and in the upper part of the valley of the burn, are considerable 



