532 [Proc. B.N.F.C., 



to the summit of the reputed Drumceatt, where a great 

 national Assembly was held a.d. 575. A better point could 

 not have been selected for the Belfast naturalist to get a 

 panoramic view of the proposed field for their three days' 

 survey; indeed every lover of our country should appreciate 

 the advantage of such a prospect, in which the varied physical 

 features in view are so attractive, and the historical associations 

 connected with the district are so eventful and romantic. 



At this spot the formal field meeting was constituted, and 

 Mr. John Vinycomb, M R.T.A., was elected Chairman. 



From this hill as we look to the east we have Innisowen 

 Mountain, Lough Foyle, and the flat Valley of the Roe to the 

 left hand, and away to the right the hills of Derry, Tyrone, and 

 Donegal, with Dungiven on the higher reaches of the Roe 

 Valley, and right in front of us we have the mountain and 

 escarpments that form the western limit of the great northern 

 basaltic plateau. The very broken outline of Binevenagh to 

 the north, and in successson southwards Keady Hill, Boyd's 

 Hill, Donald's Hill, and Benbradagh, the intervening space 

 from the bed of the Roe, gently rising to the base of the hills, 

 being geologically constructed very much like the section from 

 the bed of the Lagan to the crest of Divis or the Black moun- 

 tain — with this important difference that in the Lagan Valley 

 the carboniferous rocks are absent, whereas in the Roe Valley 

 there occurs in ascending order the Silurian, the Carboniferous, 

 the New Red Sandstone, the Cretaceous, and the basaltic rocks. 

 Like the Valley of the Lagan the Upper Roe cuts through the 

 new red sandstone, and it is owing to this that the water of the 

 Roe gets its red colour, from which it is named the Roe. 



The great valley is very remarkable for its numerous 

 indications of the oscillations that took place in the level of the 

 land surface distributed over the valley. These oscillations 

 marked the end of the Tertiary period, arid possibly continued 

 after the appearance of man. Without going into a minute 

 analysis of the relationship between the existing deposits of 

 gravels, clays, &c, one example will probably illustrate the point. 



