338 TYIfEDALE ESCARPMENTS; 



Drift have allowed conditions of waterflow to be fully re-in- 

 stated; and atmospheric action has enjoyed every opportunity 

 to sharpen them anew. ISTear the valleys, on the other hand, 

 glaciation promoted a suppression of the features already in pro- 

 gress, and drift still greatly covers the ground ; and it seems cer- 

 tain that in many places, especially in neighbourhoods where 

 proximity to the sea-level must prevent the river — the great ad- 

 junct to all the sculpture — from reaching the bottom of its old 

 valley, the earlier features can never be reproduced while sea and 

 land remain as thev are."^' 



Post Glacial Atmospheric Action. — Pursuing a general chrono- 

 logical sequence we now come to the post-glacial effects of at- 

 mospheric action. 



That the glaciers must have scoured away all loose debris, and 

 effaced all shallow markings, need not be doubted. As post-glacial, 



* Upon the subject of the ghiciation of escarpments I regret to find myself in opposition 

 to such eminent authorities as Dr. James Geilde, and Prof. A. H. Green (Great Ice Age, 

 2nd Ed., p. 28G: Green's Geology, 1st Ed., p. 446). Professor Green thinks that many 

 escarpments in the North of England have been " planed clean away " by the ice, and have 

 only been re-developed on the heights by post-glacial waste. I must hold that the rounded 

 brows of Tynedale escarpments tell a different tale; for since it is wear and tear of the 

 face and brow that produces escarpments, the body of the features cannot have been 

 formed anew while these have remained stationary. I have on this point confined my- 

 self to facts, having no theory to offer. It is hard to believe, however, that forces which 

 could pile the moraine-mountains of the Dora Baltea, should have left such trivial marks 

 upon Ncn-thumbrian escarpments. 



A remark may be made here upon the "Northumberland Lakes." It has often been 

 poiuted out that hollowed basins, such as they are, occur in front of large glacier-obstruct- 

 ing masses of Crag-and-Tail. This staterhent the Crag- and Broomlee Loughs, with the 

 great projections of whin at their East ends, seem markedly to exemplify. I have else- 

 where stated, regarding Broomlee Lough, that the escarpments about it bend round as if 

 giving place to it; and have therefrom deduced its origin by glacier erosion. Gcol. Mag., 

 1876, p. 28G. The fact is correct; but since I have seen more of escarpments I am less 

 sure of the deduction. If the glacier scooped these lakes in the midst of escarpments 

 without planing them down, was it not a feat somewhat resembling the ancient ordeal 

 of walking blindfold across red-hot iron bars without touching them? It is worth re- 

 cording, that in a transverse section, which I obtained of that lough at Dove Crag, by 

 swimming across with a line and sounding every twenty strokes, there is no symptom of 

 any ridge, although one or two descend upon its shore. They may be silted over; but 

 the lough is close to the watershed, is entered only by trifling streamlets or sikes, and is 

 said to be fed by springs within it. 



