70 J. G. GOODCHILD ON THE GLACIAL PHENOMENA OE THE 



the Dale-district ice, laden with Carboniferous fragments, flowed 

 over the Howgill Fells towards the lower ground of the upper part 

 of Lunedale. 



Owing to this diversity of directions taken by the various strata 

 of the ice over any one place, it is next to impossible to draw any 

 line that shall indicate precisely where the line of shedding was : 

 that represented upon the map (PI. II.) must be understood to be an 

 approximation to the shedding-line of only the lower part of the ice- 

 sheet thereabouts. 



The instances of cross-glaciation mentioned as occurring in the 

 Eden- valley seem to show that the component forces that resulted 

 in the easterly turning of the Eden-valley ice-stream must have 

 been very nicely balanced ; so that where a stronger current from the 

 south set in, the Eden-valley ice was sent further to the north, and, 

 on the other hand, where the local northward-flowing ice exerted 

 less power, the Eden-valley stream advanced towards the line of ice- 

 shedding. In this way we can easily account for the fact that none 

 of the Eden-valley ice, after crossing Stainmoor, found its way down 

 Arkendale into iSwaledale. There is nothing whatever in the form 

 of any of the surrounding ground to prevent a marine current from 

 passing that way ; on the contrary, every thing seems favourable for 

 a dispersal in that direction ; but, as a matter of fact, there is not 

 a single fragment known of any rock in the drifts about Arkendale 

 Head that may not have been derived from the rocks near at hand. 

 One can understand this easily enough when it is known that a thick 

 sheet of ice from the Eells at the head of Swaledale flowed right 

 across the head of Arkendale, and kept the Stainmoor drifts a long 

 way to the north of the line they would have taken had no such 

 ice- sheet been in existence ; but how are we to explain these facts 

 by any theory of marine action ? 



Wo reference has yet been made in this paper to the dispersal in 

 a southward direction of Shap granite in the basins of the Mint 

 and Lime on the south side of the Lake-district watershed. This 

 was almost certainly owing to the lowness of the ground between 

 the Shap-granite area and the Howgill Eells, in consequence of 

 which the local ice had not suflicient bulk to keep the upper part of 

 the Eden-valley ice-stream far enough to the north to prevent its 

 overflowing into the area south of the watershed. The striated rock- 

 surfaces indicated on the granitic area itself seem to bear out this 

 conclusion, as the rounded sides of the rock face to the north, as if 

 the ice came from that direction. There seems, however, to be some 

 reason for thinking that this cannot always be relied upon as a test 

 of the way", the ice flowed, as in one instance, in Garsdale, where it 

 seems tolerably certain which way the bulk of the ice went, the 

 rounded surfaces face away from the source of the drift. This may 

 be due to a local variation in the ice-current ; but at any rate it 

 will serve to caution us not to trust entirely to the appearance of the 

 dressed surface as evidence of the direction of flow of the ice.- 



It seems that there are but few glaciated districts that afford an 

 opportunity of making an approximation to the thickness of the ice 



