78 J. G. GOODCHILD ON THE GLACIAL PHENOMENA OP THE 



the kneading up of all the sand into the drift in such a way that 

 every trace of stratification would be obliterated. 



All the drifts mentioned above contain a far smaller proportion of 

 clay than we should be led to expect, when we take into account 

 how much shale there is in the dale-rocks. Taking them altogether, 

 it would perhaps be rather an underestimate if the proportion of 

 shale to the whole mass of rock in the area here treated of were set 

 down at one half. Yet extensive deposits of drift may be met with, 

 into the composition of which clay hardly enters at all. Even in 

 the till, the most clayey of all, it is doubtful whether the propor- 

 tion of clay to stones is any thing like that of the shale to the 

 other beds. 



Again, if we consider how large a proportion of limestone and of 

 some of the finer and softer sandstones must have been ground into 

 mud by the ice, it is not very easy to understand how any very 

 large proportion of the drift can really be the moraine profonde of a 

 great ice-sheet. An enormous quantity of clay must have gone out 

 of the dales somewhere ; and it certainly is not clear how the ice 

 should carry away so much of the finer detritus of the rocks that it 

 passed over, while it left the coarser parts behind. A possible 

 explanation of this may be that the greater part of the stones in the 

 drift may be but the remodelled result of the preglacial weathering 

 of the dale-rocks — that, in fact, the drift is but a mass of glaciated 

 stones originally derived from the old fell-side screes. The objection 

 to this is, that wherever any bed of rock occurs of such a lithological 

 character that it can be traced with some degree of certainty in the 

 drift, it can almost always be proved that it has travelled many miles, 

 in some cases even hundreds of miles, from the parent source — as, for 

 example, the-Shap granite, which has gone as far south as the Yale of 

 Gloucester. What, therefore, is true of any marked bed of rock, 

 must be equally true of all other rocks that have undergone the like 

 amount of glaciation. It is therefore very unlikely that any large 

 quantity of the old subaerial waste of the dale -rocks has been left 

 anywhere near where it was when the ice first reached it. Judging 

 by the distances other rocks can be proved to have been transported 

 by the ice, the thick accumulation of preglacial surface-waste must 

 have been swept away to great distances. Hence, instead of looking 

 for traces of such detritus near the parent rocks on the eastern side 

 of the watershed, we should rather expect to find them somewhere 

 about the east coast, or in the North Sea, if there were many stones 

 tough enough to withstand the effects of a transportal to so great a 

 distance. 



When we turn to the drifts of the upper part of the Eden valley, 

 we find nearly the same order as obtains in the dales. The lowest 

 drift of all is of the character of the ordinary till, a stiff clay of 

 various colours, according to the kind of rock that most of it was 

 derived from, and full of stones, most of which are well glaciated, 

 and are generally of comparatively small size. 



It is not always possible to distinguish the till from the deposit 

 that overlies it. Occasionally, and especially in the vicinity of 



