go DR. J. A. SMYTHE ON 



Crags pointing a little east of south, the other a little east of 

 the top of Thirlmoor, pointing E.S.E. 



No striae have been recorded from the high border fells and 

 the adjacent valley sides between the North Tyne and the 

 Rede ; other evidence indicates that this district escaped the 

 invasion of foreign ice. 



The evidence of the striae thus points to the overriding of 

 practically the whole county, outside of the Cheviots, by ice 

 from the west, followed by the movement of a sheet south- 

 wards from the Tweed around the flanks of the Cheviots 

 towards the Aln, and down the whole coastal area to the 

 Tyne. In the large valleys, e.g., the North Tyne [16] and the 

 Coquet, there is evidence of the flow of moderately large 

 glaciers at the close of the glacial period. 



II. — The Boulder Clay. 



Under this head may be grouped a great variety of glacial 

 deposits, which have clay or rock-meal as their chief con- 

 stituent. These deposits differ greatly in character and com- 

 position according to their position and origin, and though 

 in the great pre-glacial valleys some classification of the 

 component beds seems possible [19], this is impracticable 

 when the whole area is considered. What may be called the 

 typical Northumbrian boulder clay is a bluish or grey plastic 

 clay charged with well scratched boulders of limestone and 

 sandstone; whinstone, too, is a common constituent east and 

 south of the outcrop of the Whin Sill. This clay occurs, with 

 but slight modifications of texture, in places over the whole 

 county apart from the Cheviots, and is generally that particular 

 clay which rests on the rock-surface. In the Cheviots its place 

 is taken by a less impervious deposit, more of the nature of 

 broken rock than clay. In hilly districts outside of this region 

 (the Carboniferous uplands) a boulder clay of local origin is 

 frequently encountered, the boulders being but little polished 

 and scratched and the matrix more sandy. Many sections 

 show this local till to rest upon the typical clay. 



