part 3] GHACIATION OF NORTH-EASTERN IRELAND. 381 



common on the col between Divis and Wolf Hill, at a level of 

 1100 feet. 



Cave Hill, the bold escarpment of basalt which overlooks Belfast, 

 must also have been covered during the period of maximum deve- 

 lopment, as were Squires Hill and the long ridge which runs from 

 it in a north-westerly direction by Mcllwhans (1128 feet) and 

 Boghil (917 feet) to Lyles Hill (747 feet). This ridge is cut 

 through by several dry gaps, which carried off the drainage from 

 the ice-front at a late period of its retreat, and the northern spur 

 of Mcllwhans is cut by three such channels. 



The valley between Gave Hill and Knockagh contains great 

 quantities of boulder-clay, characterized by the presence of the local 

 basalt with chalk, flint, and various Scottish rocks (including Ailsa - 

 Craig eurite). 



The district between Templepatrick and Antrim is covered with 

 boulder-clay containing basalt, flint, and Ailsa Craig eurite ; to 

 these are now added numerous pebbles of the Tertiary rhyolite, 

 of which there is a large outcrop on the north-east in the 

 neighbourhood of Tardree Mountain, and a smaller one at 

 Templepatrick. 



Resting upon the boulder-clay and in places on the basalt are 

 great mounds and sheets of stratified and current-bedded sands and 

 gravels. These are well seen in section in the large ballast-pits 

 on the side of the railway, a mile south-east of Antrim Station. 

 Here the section is 30 feet deep in sands and gravels, with thin 

 beds of clay. The deposits are stratified and current-bedded, but 

 the stratification is somewhat confused. The large size of many 

 of the boulders shows that the waters which transported the 

 materials must have possessed great power. 



The big boulders are principally of basalt and rhyolite, the latter 

 being present in considerable quantity. There are also fairly large 

 pieces of chalk and flint. The small pebbles include basalt, rhyo- 

 lite, chalk, flint, lithomarge, silicified wood, Silurian grit, and 

 Ailsa Craig eurite. 



A careful examination of these extensive sections failed to reveal 

 any rocks from the Tyrone Axis. 



Immediately south of the area just described lies an undulating 

 tract of basaltic country, in places heavily covered with boulder- 

 clay and gravels which, however, thin out frequently on the higher 

 ground, where the covering is scanty or the basalt actually comes 

 to the surface. 



Fine sections of boulder-clay are exposed along the course of the 

 Clady Water, a stream that rises on the slopes of Divis, and flows 

 north-westwards to the Six Mile Water, which it joins at Dunadry. 



Near Clady Bridge are several sections in red boulder-clay, which 

 is at least 30 feet thick, and contains only basalt, chalk, and flint. 

 On the Geological Survey map this area is described as basaltic 

 boulder-clay on chalky boulder-clay ; but I have been unable to 

 find any trace of the upper boulder-clay without chalk in any of 

 these sections. 



