THE GLACIAL GEOLOGY OF NORTHUMBERLAND III 



siderable power at the close of the ice-age, and that it 

 retreated pari passu with the foreign ice, the glacial lakes 

 existing only in the narrow strip of ice-free land between the 

 sheets. A view somewhat at variance with this has been ex- 

 pressed by Kendall and Muff [15]. 



The map (No. 3) represents an attempt, confessedly im- 

 perfect, to render the complex phenomena accompanying the 

 glaciation of the county somewhat clearer than is possible by 

 any verbal description, weighted as that must be by a mass 

 of details. The data furnished by the swires are in part 

 summarized in this map by the representation of the lines of 

 cleavage on the melting of some of the great confluent 

 sheets. 



Brief reference may be made to the vexed question of the 

 origin of the kaims, It has already been noted that their 

 occurrence coincides in general with evidence of the existence 

 of glacial lakes in the near neighbourhood, and also that their 

 maximum elevation is not above that of the highest swires in 

 the locality. This association seems to point to the deposition 

 of the kaim-materials in the waters of the temporary lakes. 

 The fact that in a few cases {e.g. in the valley of the Lisles 

 Burn) kaims occur without attendant swires does not invalidate 

 this conclusion, for glacial lakes discharging over the ice might 

 supply the requisite conditions. The transition from kaims to 

 moraines in the ascension of the Lisles Burn and Whisker- 

 shiels valley, and the passage upwards from morainic to kaim- 

 like matter in the same section was held by Hugh Miller [5] 

 to indicate " strongly, if not conclusively, .... the 

 morainic origin of the kaims." The recognition of the glacial 

 lakes strengthens this view by supplying a condition which 

 may be conceived as favourable to the formation of kaims. 



Appendix. 

 Pre-glacial and Post-glacial Drainage. 

 The effect of the glacial conditions upon the drainage of the 

 county has been considerable, and a brief summary of the 



