W^.'Kiii r — Minor Verioilitjitu in Ol<ici(tl Itelreat. 9;> 



They ollored to the outflowing ice fioin t'lie Kcnmavc centre five main 

 avciHies ol' liischavge towanls the iiortii. These were I'roin we.sL to east— (1) 

 tlie Car.igli Valley; (l2) the (lap d' Dunloe; (:J) the Killaiiiey Valley; 

 (4) the valley of the Cappasrli Kiver and Ijougli Giiitaue; (5) the valley of 

 the Loo and Flesk. The ice tongues whieli occupied these passes, and thence 

 deployed on to the northern lowland, will in this paper be referred lo as tlie 

 Caragli, ])unloe, Killarnoy, Guitane, and Flesk glaciei-s respectively. Tlie 

 existence of the Guitane and Flesk glaciers was cut short at an earlier stage 

 of the retreat than that of the Caragh, JJunloe, and Ivillarney glaciers, 

 because the passes through whicli they were fed lay at a greater distance 

 from the centre of distribution. The history of ihe retreat subsequently to 

 the abandonment of these passes is recorded in the valley of t!ie Eouglity 

 Eiver, east of Kenmare. The greater part of the letreat of the ice-maigin as 

 it shrank from the plain into the passes, and from the passes south and west 

 to the ice-shed seaward of Kenmare, is ciiaracterized by a marked periodicity. 

 It is clearly a matter of great interest lo inquire into tlie nature of this 

 periodicity, and get some idea of the duration of the oscillation.s which it 

 indicates. One might express one's aim in such an investigation as being an 

 attempt to determine a climatic "grain" as characteristic of a definite period 

 of late glacial time. In addition to the obvious importance of comparing 

 the minor climatic variations of such a distant period with those of the 

 present day, there is the possibility of correlation with other areas, where 

 the retreat shows a similar character. 



As the evidence upon which the tentative conclusions of the present paper 

 are based is most clearly defined in the Kenmare Valley, it will be necessary, 

 before proceeding to the main issue, to describe in some detail the conditions 

 which obtained in this area during the retreat. 



Icc-damincd Lalcts of the Kenmare Valley. 

 During the whole period of the retreat of the ice-front from Jlorley's 

 Bridge on the east to the ice-shed west of Kenmare the drainage of the 

 lloughty Valley was entirely reversed and discharged along the line of the 

 railway via Morley's Bridge and Loo Bridge into the valley of the Flesk. 

 This obstruction of drainage resulted in the formation of a glacial lake, the 

 surface of which lay at a level of 320 feet O.D., determined by the height of 

 the outlet at Morley's Jhidge The maiginal terraces and embankments of 

 this lake form one of the most striking features of the valley, and in distinct- 

 ness and massiveness rival those of Glen Boy and Gleu Spean (see Plate XV). 

 They prove the lake to have had during its greatest extent a length of at 

 least twelve miles, ami lliniu(j;hout this distance show no departure from 



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