part 3] GLACIATION OF NORTH-EASTERN IRELAND. 363 



Glenshesk. This channel is much smaller than those on the south. 

 The present level of its intake is 590 feet ; but there is a thickness 

 of at least 20 feet of peat above the solid rock, and the upper part 

 of the valley is occupied by a long, narrow, swampy lake. 



At or about this stage, the Scottish ice was no longer able to 

 surmount the rampart of Fair Head and the cliffs above Murlough 

 Bay and Torr Head ; but the drainage from the ice, which stood 

 level with, or slightly above, the summit of the cliffs, still found 

 its way into the lake which occupied the head of the Carey River, 

 and cut several channels through the Fair Head dolerites. The 

 northernmost of these runs from the summit of the cliff, above the 

 colliery at Portdoo, into Lough Na Cranagh, and another through 

 Lough Fadden. 



West of Ballycastle are several well-marked channels which 

 drained small lakes held up by the ice in the basin-shaped 

 valle}^ opening on to the line of sea-cliffs. These channels 

 conveyed the water southwards on to the area of the bog, which 

 lies between the basaltic uplands along the coast and the great 

 Armoy moraine. Thus the waters of a temporary lake in 

 Glenstaghey drained by a channel crossing the bog west and 

 south of Carnsaggart, and those of the area around Ballintoy by 

 way of the valley on the line of the road which leads southwards 

 from Ballintoy School, the watershed in this case being at about 

 450 feet. 



Finally, at the western end of the valley above Dunseverick 

 "there is a very big dry channel, cutting through the watershed 

 from Lisnagunogue to the terminus of the electric railway at the 

 Giant's Causeway. 



The accumulated waters from the area between the uplands and 

 the moraine found their way to the sea through a gorge-like valle}' 

 now occupied by the Bush River. This valley, from the point 

 where the river cuts the 100-foot contour to the town of Bushmills, 

 has steep sides and a flat floor, and the present stream has little 

 •cutting power owing to its low gradient. This part of the valley 

 as cut in basalt, and in several places : for example, at The Island, 

 where the valley is over 50 feet deep and quite narrow, cliffs over- 

 hang the stream. Although the valley still carries the waters of 

 the Bush River, a not insignificant stream, from its size and 

 contour I should judge that it had required a much more powerful 

 agent for its erosion. 



From Bushmills to Portrush the cliffs are high and rugged, and 

 I could find no features of glacial interest upon them. 



The low-hying tract extending from Portrush to the River Bann 

 consists largely of glacial accumulations and wind-blown sand, and, 

 when that river is crossed, the basaltic slopes are found to be 

 covered with glacial deposits, both gravel and boulder-clay, which 

 yield strong evidence of their northern origin. Thus, at the brick- 

 works south of Irish Houses, there is a section 15 feet deep in 

 brown boulder-clay, containing big boulders of basalt, Carboniferous 

 Limestone (striated) and chalk, and smaller masses of quartzite, 



