BETWEEN THE TYNE AND THE WANSBECK 8 1 



Although it is probable that most of the elevated rocky- 

 tracts in this district are similarly moutonneed, yet for various 

 reasons the point is difficult to establish in particular cases, so 

 that only those examples have been described in which the 

 evidence seems complete. 



III. — The Drift. 



The distribution of the superficial deposits primarily pro- 

 duced by moving ice is very irregular, both with respect to 

 the extent of surface covered by them, and to their thick- 

 ness in particular places. It is obvious, even on a cursory 

 inspection of the country, that the higher land is relatively 

 free from these deposits when compared with the lower-lying 

 land. Large tracts of country about Whalton, Bolam, Belsay, 

 Shafthoe, Inghoe, and Mootlaw, for example, are quite free 

 from cover, while lower down, in the basin of the Pont and 

 Blyth, one could walk for miles without encountering any 

 exposure of rock.* A more accurate (even though somewhat 

 approximate) estimate of the relative surface-distribution of 

 rock and drift, and the dependence of this upon the contour, 

 can be got by planimetric measurements on the Drift Maps of 

 the Ordinance Survey. 



Such measurements have yielded the following results for 

 the country within the drainage-area of the Blyth as far as 

 Stannington, together with that drained by the upper reaches 

 of the Ouseburn and Dewley Burn : — 





Area in 



Square Miles 



Percentage Areas 



Height of Land 





OF 







OF 





IN Feet. 



Drifi 





Rock. 



Drift. 





Rock. 



Under 200 



... i6-5 





0-2 



98-8 





1-2 



Between 200 and 300 



... 307 





2-5 



92-5 





7-5 



,, 300 and 400 



19-6 





3-4 



85-2 





14-8 



,, 400 and 500 . 



I9-8 





3-9 



83-6 





i6'4 



,, 500 and 600 . 



IIT 





2-6 



81 -o 





19-0 



Over 600 



6-9 





4-1 



627 





37'3 



The well-characterised components of the drift in these parts 



• Note- that hereafter "rock" will be used in the ordinary sense of "living" 

 rock, to distinguish it from the drift or superficial deposits. 



