234 Proceedings of the Royal Iriah Academij. 



The distribution of the drift proves tliat the large glacier occupying the 

 Erne valley flowed southwards and eastwards. Thus Maxwell Close noted 

 "two good-sized lumps of micaceous schist" in the drift near Enniskillen, and 

 continues : "These must tiave travelled fifteen miles at least from the 

 north-west." Thougli the source of these boulders is probably the meta- 

 morphic region north-west of Lough Erne, their possible derivation from the 

 0. E. S. conglouierates may not be excluded. Indeed, very few boulders 

 unmistakably referable to the igneous and metamorphic complex extending 

 from Ballyshannon to Lough Erne were encountered in the ICrne valley, the 

 great bulk, almost all, of this material being transported westward and out to 

 Donegal Bay. The ice-shed lay, in general, somewhere to the east of the 

 triangular Archaean tract. 



The topography of the country, moreover, south of Slieve Beagh and in 

 the Enniskillen valley suggests the passage of glacial streams from Lough 

 Erne southwards, at least in the late-glacial phase ; the drumlins indicate 

 the passage of ice along tlie valley, and a swinging of the ice at Newtown 

 ]kitler round tlie south-west slopes of Slieve Beagh. This would appear to 

 be part of a great fanning of ice executed about Ballyhaise and Cavan, as- 

 the drainage lines, features, and drift in all this area are clearly indicative 

 of ice flowing from the north-west. Indeed, the chief relief of this Enniskillen 

 ice was manifestly found in the direction of Cavan. 



The south-east trend of the ice is seen as far as the south-east confines 

 of the region described in this paper, and over that area situated to the south 

 of it, tlie ice passing over Keady, Castleblayney, and Carrickmacross, and out 

 into Dundalk Bay. This is proved by the striae recorded by the Geological 

 Survey, and by the form of the ground, as seen during a hurried traverse of 

 the country. The same direction was taken by the ice in the adjacent region 

 dealt with in A. E. Dwerryhouse's paper. A perusal of the Geological Survey 

 maps and memoirs suggests that the southerly motion of the ice over at 

 least the northern part of the Central Plain was due in some measure to 

 the impetus imparted by the ice-sheet of N.-W. Ireland. 



In fine, from this great ice-shed, extending from the Glendowan Mountains 

 in the north-west to the south of Lough Erne and Sligo in the south, huge 

 glaciers passed radially outwards,' on the south-west over Donegal Bay, on 

 the west and north over the Bosses and Northern peninsulas, on the north- 

 east over Inishowen and the Sperrin Mountains, on the east down the valley 

 of the Bann and over Cookstown, Dungannon, and the plain of Tyrone, and 

 on the south along the valley of the Erne, over the Clogher valley and Slieve 

 Beagh, to the Central Plain. 



