46 ME. J. E. HARR ON THE TARNS OF LAKELAND. [Feb. 1 89 5, 



Blea Tarn, at a height of 1561 feet and with a maximum depth 

 of 33 feet, occurs higher up the same valley as that in which 

 Watendlath Tarn is situated. There is rock on the left bank at 

 the outlet, but a great mass of drift on the right bank far below the 

 required 33 feet. 



Harrop Tarn, the shrunken remnants of what was once a much 

 larger sheet of water (see figs. 10 & 11), is only 12 feet deep, and has 

 solid rock in the bed of the stream at its exit. From the northern 

 end of the tarn, however, runs a drift-filled depression, the col of which 

 is about 30 feet above the lake. This drift passes down a valley 

 which is now dry and running JST.W. of and parallel to Dob Gill (the 

 present stream from the tarn), to a distance far below that required 

 for the formation of the tarn. This valley, a short distance below 

 the col, is much deeper and 



more important than that of Fi n^Section across Dob Gill 

 Dob Gill, and is m direct and mUey t0 Km y iL 



continuation of the valley 

 descending from the water- 

 shed between Blea and 

 Harrop Tarns, while Harrop 

 Tarn itself lies in a lateral 

 valley once passing into this. 



Clifton Ward, in his paper on 'The Glaciation of the Southern 

 part of the Lake District and the Glacial Origin of the Lake-basins 

 of Cumberland and Westmoreland,' notices some tarns which I have 

 not recently examined. Of these he admits that Bed Tarn on Hel- 

 vellyn and Keppelcove Tarn, a little farther north, are possibly 

 moraine-dammed, but thinks that Blea, Little Langdale, Elterwater, 

 Loughrigg, and Hard Tarns (the latter a small pool on Helvellyn) 

 are rock-basins. I have seen all these tarns, except Hard Tarn, in 

 former years, and, from what I know of the nature of the ground, 

 I believe that old moraine-blocked valleys will be found in these 

 cases also. 



VIII. Conclusions. 



It will be seen that the evidence furnished by these tarns is of 

 different value. In the case of some, such as Smallwater, Codale, 

 Burnmoor, Lever's Water, and Harrop, the difficulties of account- 

 ing for the conformation of the ground otherwise than by the 

 explanation which I have offered are very great. In others the 

 evidence is not so strong, owing to the complete or almost complete 

 concealment of the alleged old valley by drift. But in no case which 

 I have examined can the advocate of the rock-basin say that the 

 buried moraine-valley does not exist. Until he can do so, I feel 

 justified in asserting that the tarns of Lakeland give no support to 

 the theory that the basins in which they occur were hollowed out 

 by ice. To prove this it must be clearly shown that a moraine- 

 blocked valley does not exist, whereas in some cases I maintain that 



