402 MAJOR A. E. DWERRYHOUSE OX THE [vol. lxxix, 



closed deep of very irregular form, which in places reaches the 

 10-fathom line ; but, between this and the open sea, is an area 

 ahout a mile wide which is less than 5 fathoms deep. That this 

 is not due to the silting-up of the mouth of the Lough, or to its 

 obstruction by morainic material, is indicated by the presence of 

 numerous reefs and islands of Carboniferous Limestone between 

 Greenore and the sea, from which it would appear that the Lough 

 occupies a rock-basin. 



An examination of the direction of the strise on the rock-surfaces 

 bordering the Lough shows that the ice, after passing the narrows, 

 fanned out over the more open country on the south, flowing over 

 •Greenore and Whitestown on the one hand, and towards Kilkeel 

 •on the other. 



The drifts of the triangle contain great numbers of boulders of 

 the Newry granite, and a smaller quantity of Silurian debris, while 

 basalt and flint from the north are not uncommon. 



The glacial drainage-channels which form so conspicuous a 

 feature in this area must now receive attention. The largest of 

 these is over 20 miles long, and connects the low-lying swampy 

 area south of Portadown with the head of Carlingford Lough at 

 Warrenpoint. 



The country immediately south of Portadown is an almost level 

 swampy plain, rapidly narrowing about 2 miles south of the town 

 to form a deep flat-floored valley, through which pass the River 

 Bann, the canal, and the Great Northern Railway. The Bann 

 enters this valley near Gilford, and flows northwards through 

 Portadown into Lough Neagh, the fall being very slight and the 

 stream sluggish. Near the point where the Bann enters the 

 valley, but in this case from the south-west, another stream, 

 the Cusher River, flows in, and also runs northwards, joining the 

 Bann near Portadown. 



From Gilford southwards by Scarva to Poyntzpass, the valley- 

 floor is streamless and almost level ; but near the latter village 

 small streams enter from both sides, and flow southwards. The 

 valley continues to fall southwards, and passes through Jerrettspass 

 and Newry to Warrenpoint, the part between the two last-named 

 towns being at sea-level and carrying the Newry Ship Canal. 



The whole of this valley is below the 100-foot contour, and is 

 altogether out of proportion to the drainage which it carries. 



The Newry River, after an extremely erratic course, falls into 

 the great valley about 3 miles above the town of Newry, but 

 between that point and Gilford the channel is practically stream- 

 less. The origin of this valley I attribute to the drainage from 

 the Lough Neagh Basin, which during the period of the advance 

 of the Scottish ice, must have taken this course. 



The valley is deeply cut in the solid rocks, and can be seen to be 

 somewhat encumbered by the drift of the western ice by which it 

 was crossed. The deposits of this ice almost obliterated the 

 northern part of the channel, which however was partly re-excavated 



