Wiuf;iir — Jfi)io)- I'crioilicil// in Glacial Retreat. 97 



Glasliagoiiuv, lias an iinposiny^ delta about a quarter of a square mile in 

 extent. Tlie hill s^lnpi's to lliu north of Kilgarvan, and thence east to 

 Morley's Ihidge, sliow <inly a few insignificant traces of terraces, and yet there 

 were at this poinl a number of small streams descending into the lake. 



Perhaps tlie most remarkable proof of the importance of the glacial 

 ilrainage in the buildin;; of tlie lake terraces is tlie fact that in the Slahcny 

 and Owbeg Valleys the terraces occur only on the western side of the valleys, 

 and are almost completely wanting on the eastern. Tlie gravel and sand 

 carried along by tlie marginal streams were brought to rest at the lake level 

 in these valleys, and so travelled no farther towards the east. The slopes of 

 the main valley immediately east of these laterals are devoid of terraces for 

 the same reason. 



Some very striking and instructive phenomena bearing on this point are 

 to be observed in the valley of the Cleady River, thi-ee miles north-east of 

 Kenmare. The lake terraces in this valley can be traced into a massive 

 series of gently sloping fluvio-glacial terraces, which continue up the western 

 branch of the river towards Gowlane, but are completely wanting on the 

 northern branch, which comes down from Coombane. The western branch, 

 along which the terraces occur, is found to occupy throughout part of its 

 course a glacial drainage channel, and this channel can be followed over tlie 

 pass to the south-west of Gowlane at an altitude of 500 feet, and along the 

 slopes of Peakeen in the direction of Carrig East. It is clear from a 

 consideration of contours that the marginal drainage must have gone along 

 this channel and over the pass by Gowlane from the time when the ice-front 

 first set free the mouth of the Cleady Valley uiitil it sank to the oOO-foot 

 level on the western slope of Strikeen. Immense quantities of sand and 

 gravel were thus transported along this route into the western branch of tlie 

 Cleady Hiver, and there, being checked by the waters of the lake, built 

 themselves out into great Huvio-glacial fans. 



The terraces of Lake Kenmare, when followed westward, appear at first 

 sight to come to an end at Cleady. One might conclude that, when the ice had 

 .retreated thus far, the lake had for some reason ceased to exist, were it not that 

 there is a well-developed group of terraces at exactly the right level of 320 feet 

 below Letter in the headwaters of the Finnihy River. These prove that the lake 

 must in its later stages have had a considerable extension to the west of 

 Cleady. Why, then, are there no terraces along the slopes from Cleady to 

 Strikeen, and thence north-west as far as Letter? The reason is clear once it 

 is recognized tiiat the marginal drainage is essential to tlie building of tiie 

 terraces. From Cleady to Strikeen they are wanting because, as lias been 

 pointed out above, the drainage during this period of the retreat went over 



