part 3] GLACTATION OF NORTH-E ASTERN IRELAND. 373 



— Scawt Hill — Black Hill, which separates Glenarm from the 

 coast, and discharged gravel-laden waters into the eastern arm of 

 Skeagh Water Lake by three channels, at levels immediately above 

 1000 feet, lying south of the road from Larne to Skeagh Bridge. 

 Each of these channels has a well-marked gravel-delta, at a level 

 of between 950 and 1000 feet at its western end, these deltas 

 marking the water-level of the lake during the period of the over- 

 flow by the Skeagh channels into the Owenacloghy Lake. By this 

 time the ice had fallen back sufficiently far to free the upper part 

 of the Owenacloghy valley, and to allow of the formation of a lake 

 in that depression. 



At this stage, the Owenacloghy Lake probably drained across the 

 low ground between Douglas Top and Sliemish Mountain, and so 

 by the Douglas Burn into the Glenwhirry River. The col is now 

 occupied by an extensive peat-moss, and so the overflow-channel, 

 if such exists, is completely obscured. 



With a further retreat of the ice-front the Owenacloghy and 

 Linf ord Lakes became confluent, a channel was opened through the 

 col between Robin Young's Hill and Scawt Hill, which discharged 

 much water and gravel into the lake from the eastern ice, and the 

 waters of the combined lakes overflowed westwards at a height of 

 720 feet, by way of an extremely well-marked streamless channel 

 between Tuftarney Mountain and Slievenamona, into the Braid 

 River. 



The waters appear to have stood at about this level for a long 

 period, and it will be remembered that this is also about the level 

 of the terrace mentioned on p. 372, extending from Linford Bridge 

 to Feystown. 



Further recession allowed of the escape of the water into the 

 head of Glencloy, by channels at 710, 670, and 630 feet respec- 

 tively. The first of these is close to the main road from Bally - 

 mena to Glenarm, the second midway between that road and the 

 summit of Drummore, and the third north of that hill. 



The country between the basalt-escarpment and the North 

 Channel, from Glenarm Bay to Ballygalley Head, consists of out- 

 crops of Chalk, Liassic rocks, and Triassic sandstone and marl. 

 The surface is much broken by landslips, most of which are of 

 post-Pleistocene origin, and (as a result) the glacial phenomena 

 are extremely difficult to follow in detail. All the drift-deposits 

 of this area are of the northern type, and pebbles of Ailsa-Craig 

 eurite are extremely common. 



At several places along the coast-road are exposures of Glacial 

 gravels containing, along with the northern erratics, fragmentary 

 marine shells, and in one section at Ballyrudder an extensive collec- 

 tion of shells was made by a committee of the Belfast Naturalists' 

 Field-Club, the section being also carefully described. 1 



Southwards from Ballygalley Head to Larne, and inland to the 



1 Proc. Belfast Nat. F. C. ser. 2, vol. iii (1893) pp. 518-25. 



