Chaklesworth — Glacial Geology of North-West of Ireland. 287 



lateral moraine. This has impounded the drainage of this slope of Slieve 

 League, giving rise to Croleary Lough, a lakelet in the corrie recess.^ 



Ice proceeding towards Donegal Bay from the hills to the south of 

 Glenties and the Binbane range would have a strong south-westerly 

 component in its motion, the effect of which would be to cause the glacier to 

 stand well away from the eastern escarpment of the Glengesh Plateau at its 

 northern end, while pressing closely against the face of the hills on the west 

 and south-west ; in the north a large lake would in consequence be formed 

 discharging through the " Neck of the Ballagh," to Ardara, while along the 

 west and south-west edge there would be space only for marginal streams 

 carrying off the waters from the melting ice-front — e.g., the valley west of 

 Sheannacon Hill. 



At Clogher, IST.-E. of Muckros, enormous numbers of blocks of all sizes 

 strew the ground, showing some tendency to linear arrangement. These may 

 represent moraines, as J. F. Campbell suggested,- yet they may, with more 

 probability, be regarded as a measure of the rock destruction of the maximum 

 phase of the glaciation. 



Over the whole of the drumlin country north and east of Donegal Bay I 

 have been unable to detect any sign of the mode of the withdrawal of the 

 ice.' The plain north of Ardara is almost equally destitute of memorials of 

 the retreat. South of Wood Hill (Ardara) and along the foot of Mogumna 

 Hill there runs a morainic ridge ; the course taken by the marginal stream 

 can also be clearly seen. Another short lateral moraine margins this plain to 

 the east of Kilrean (about one-and-a-quarter miles S.-W. of Glenties). Lough 

 Kip (one-and-a-half miles W. of Glenties) is held up by a similar morainic 

 ridge. The large valley, now quite streamless in its upper portion, leading 

 from Letterly Ho. to Maas, may have served as the means of escape for the 

 melt waters when the ice spread out over the country to the west of Glenties, 

 and may have been in action at the time of the formation of the morainic 

 ridge south of Lough Kip. 



1 This moraine, according to another view (Geol. Survey Mem. , Sheet 22, 23, 30, and 31 

 (in part), p. 55), was formed by a corrie glacier descending from the heights of Slieve 

 League. 



- "The most conspicuous moraine that I have seen in the British Isles is at a point 

 at the northern horn of Donegal Bay at a place called Clogher . . . ; it consists of at least 

 six parallel ridges of angular stones. Thelai-gest of these are as big as small houses, and 

 they rest where they were tilted off the ice." (Quar. Jour. Geol. Soc, vol. xiix (1873), 

 p. 211.) 



^The N.-S. ridges in the valley of the Eanybeg Water, about half a mile N.-W. of 

 Drumagraa L., externally resemble moraines. The material is very angular, shows no 

 stratification, and may represent the broken and jumbled rock masses shattered by the 



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