J. E. Marr — Physiography of Lakeland. 491 



mentioned road. Here an interesting section is seen of extremely 

 fine laminated loam, resting upon the Boulder-clay, which, however, 

 contains seams of a similar loam. This appears to be the section 

 drawn in Mackintosh's "Scenery of England and Wales," p. 393, 

 though all the details shown there are not now visible. 



These stratified deposits are of such a nature that they would be 

 unhesitatingly referred to " mid-Glacial gravels " by some writers ; 

 but on this view the presence of the fragments of Skelgill Shale 

 will be difficult to explain. It is true that the Skelgill Beds occur 

 at a level higher than that of the gravel both to the north-east and 

 south-west of Church Beck, but they certainly cannot have been 

 brought by ice from the south-west, for the movement of the ice 

 was generally from the north, nor could they have come from the 

 north-east, for the only place where they occur there at a higher 

 level than that of the gravel, is on the opposite side of the Yewdale 

 Valley, down which the main mass of ice moved in a general 

 southerly direction. The local distribution of the gravel is an 

 objection to their having been brought by floating ice in a glacial 

 sea. If they had been so brought, we should expect to find similar 

 deposits widely spread on the low ground about Coniston Lake, but 

 they do not occur there. How, then, did they reach their present 

 position ? The most plausible explanation that 1 can give is as 

 follows : — 



It has been seen that the local ice from the Old Man Eange 

 once came down the valley below Gill Head Bridge, as shown by 

 the rock striations. This glacier had certainly receded above that 

 bridge when the stratified deposits were formed. But the more 

 important mass of ice coming down Yewdale would extend across 

 the mouth of the Church Beck Valley, blocking it up, and converting 

 it into a glacier-dammed lake. Into this lake the coarse sediments 

 would be washed off the hillsides to form the gravel terrace. The 

 presence of fine loam higher up the valley, and the absence of the 

 terrace just above, suggests that at this time the local glacier was 

 about the head of the lake, and the muddy waters from it were 

 discharged into the lake to form the impalpable laminated loam. 

 The contortion of the loam, and the inclusion of patches of loam in 

 the Boulder-clay, point to slight oscillations in the glacier, which 

 at one time retreated from the lake shore, at another advanced a 

 short way into the lake. The main Yewdale glacier would shed its 

 bergs into the lake, as does the Aletsch glacier into the Marjelen 

 See, and fragments of the Skelgill Beds carried in the ice could in 

 this way be floated up and incorporated in the gravels. This 

 certainly seems the most natural explanation of the phenomena 

 exhibited in this valley. The accompanying map, when looked at 

 in connection with a general map of the district, will show how 

 favourable were the circumstances for the blocking up of the valley 

 by ice.i The 400 foot gravel appears to belong to a lower terrace, 

 formed when the Yewdale glacier had shrunk. 



' The top of the terrace does not coincide with any col. The surplus water from 

 the lake probably disappeared through rents in the glacier. 



