102 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [DeC. 13, 



flint- and chalk-rubble, and brick-earth. This drift is, in greater 

 part, of local origin, and is very irregular in its structure and distri- 

 bution ; one material predominating at one spot, and another taking 

 its place close by. Flint-rubble and sandy clays preponderate usually 

 in the lower parts of the valleys, chalk-rubble being more common 

 on the hill- slopes, whilst the brick-earth is irregularly and only occa- 

 sionally patched on the base of the hills, alternating with and re- 

 placing the flint- and chalk-rubble. 



Three of these small valleys are confluent at Salisbury. It is on 

 the north-eastern side of the one through which the Willey flows 

 that one of the best exhibitions of the Drift is obtained. The 

 following section shows the prevailing relation and structure of this 

 deposit, which here rises about 30 to 40 feet above the level of the 

 Willey*. 



Fig. 



General Section of the side of the Valley of the Willey at 

 FishertoYiy Salisbury. 







Q 



3. 





(22 



a. Gravel and Brick-earth. 



The railway-cuttings between Salisbury and Wilton expose some 

 good continuous sections, whilst several brick-fields give a few deeper 

 excavations. In a cutting adjoining Wilton, large subangular gravel, 

 chalk-rubble, and coarse rubbly brick- earth alternate and pass laterally 

 one into the other. The following section of a portion of this cutting 

 will serve to show the general character of the drift at this place. It 

 varies, however, every few yards. 



Fig. 2. — Section in the Railway Cutting E.N.E. of Wilton. 



a. Brown earth and flints ; 2 to 3 feet. 



b. Coarse gravel, consisting chiefly of suh- 



angular flints, with pieces of chert, 

 ironstone, sandstone, and some flint- 

 pebbles, in brown clay more or less 

 sandy ; 5 feet. 



c. Chalk-rubble, upper portion waved; 



passing laterally* into b. (a few Suc- 

 cinecB and Helices are found in this 

 rubble) ; 7 feet. C. Chalk. 



(* The line of division is too strong in the woodcut.) 



* It is rarely that this deposit reaches a greater height above the base of the 

 valleys in which it is found. 



