1912-13.] 657 



Areas of sand and gravel in the valley of the Roe are crossed 

 by this river, and the stream to the east of it, known as the Castle 

 River. These may be of esker rather than of moraine origin, 

 deposited between banks of an almost vanished ice-sheet ; for at 

 one point the gravelly Boulder-Clay of this (last) sheet lies against 

 or rather rests upon the gravel, as may be seen at the gravel-pits 

 near Ardmore. 



MORAINES. 



Amongst the latest relics of glacial phenomena in the region 

 are moraines, which plentifully dot the ground in the form of dry 

 hillocks on the wet peaty slopes, near the watershed between the 

 valleys, and in the middle of the Roe Valley, between the Boulder- 

 Clay tract and the tract of glacial-flood gravels to be next described. 

 The most striking instance is the remarkable group of hillocks, 

 some of them being high, steep, and impressive features, which 

 extends from above Moys to the banks of the Roe. They are no 

 doubt the outwash of glacial streams which trenched the melting 

 ice-sheet once clothing the slopes of the imposing feature of 

 Lougheramore Hill, on the west side of the valley. 



Terraces of angular basalt blocks and smaller debris line the 

 escarpment near its summit, here and there, in this valley, almost 

 from south to north. These seem to be lateral moraines which 

 margined the ice when it lowered from the height to which it 

 once attained,* to become a glacier scarcely filling the valley. 



Some well-formed moraine ridges and hillocks rest on the 

 slopes of Benevenagh below the cliffs, undisturbed by such down- 

 slipping as took place there, as was previously explained (p. 652). 

 This fact would seem to indicate that the great breaches must 

 have occurred prior to the ice-sheet of the third Stage. 



*When, for instance, it carried Metamorphic erratics to the summit of 

 Benevenagh ; and when it was sufficiently thick over Keady ridge to afford 

 conditions for the collection and flow of an esker-river starting on that high 

 ground. 



