40 



MR. J. E. MARK ON THE TARNS OF LAKELAND. [Feb. 1895, 



at one time have been a lateral valley, blocked by a moraine formed 

 by ice coming down the main valley from near Sergeant Man, 

 though I could not find any evidence that the tarn is not moraine- 

 dammed at its present exit. Like many other tarns, it has an 

 artificial dam at this point, but solid rock is not seen for some distance 

 down the stream, and the enormous blocks of loose rock which occur 

 in the stream here (washed out of the moraine or snow-slope screes) 

 would prevent the drift from being rapidly denuded. I agree with 

 Prof. Hull that this tarn cannot be considered a ' rock-basin.' 



IV. Coniston Tarns. 



Under this head I will consider a number of tarns lying beneath 

 the cliffs of Coniston Old Man and its buttresses. The first of these 

 is Lever's Water, a circular tarn, at a height of 1350 feet, which lies 

 in a valley originating in the depression between Wetherlam and 

 Carrs, the stream in which runs nearly due south to the tarn. The 

 rock occurs in situ at the exit of the stream (Lever's "Water Beck) 

 from the tarn. This stream flows in a general south-easterly 

 direction towards Coniston village. Just south of the lake lies 

 Simon's Nick, a col 100 feet above the lake, with solid rock on 

 either side. This col is situated in a moraine-filled depression, 

 which opens southward into a deep valley (now dry throughout the 

 greater part of its course), filled with moraine for many scores of 

 feet below the level of the lake (see fig. 7). The valley is far 

 deeper and more important than that through which the Lever's 

 Water Beck flows, as may be readily 

 judged from an examination of the 

 6-inch map, which, being one of a 

 Lancashire district, has contour-lines 

 25 feet apart. One cannot doubt 

 that this valley, which joins that 

 containing the Low Water Beck at 

 a spot called Pudding Cove, once 

 carried the drainage of the higher 

 part of Lever's Water Beck (known 

 as Swirl Hause Beck), and that, 

 when it was blocked by the moraine 

 of the glacier coming down this 

 valley, a tarn was formed, the water 

 from which escaped at the present 

 exit, forming the existing Lever's 

 Water Beck. 



Pig. 6. — Plan of Lever's 

 Water and Low Water. 



[Scale: 1 inch=l mile.] 



filled ' is applied to valleys blocked with moraine below the tarn, and partially 

 filled for some distance below. It is not to be supposed that sections are always 

 visible when moraine-filled depressions are referred to. The absence of rock 

 in situ and the general character of the ground are usually sufficient to establish 

 the existence of moraine-matter. Its depth, of course, could be discovered only 

 by a series of borings, which, however, it is the part of those who assert that 

 tarns occur in true rock-basins to undertake. 



