﻿356 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



serve to give an idea of the prevalent arrangement of the materials of 

 the drift on the surface of the Lower Greensand and other formations 

 where no clay occurs ; whilst fig. 5 represents examples where much 



Fig. 5. — Diagram in illustration of the Arrangement of the Angular 

 Drift, as it occurs ivith animal remains. 



x". Loam with many flints. 



x' . Argillaceous loam with few flints only. 



w. Flint drift, lower part, composed of angular debris. 



f. Inferior formation, whether Chalk, Lower Greensand, Wealden, &c. 



clay (usually overlying the mass of angular flints) has preserved the 

 hones of animals in the drift. 



In speculating upon the former causes which might have distri- 

 buted the debris in the irregular manner above described, at such 

 various heights and so completely out of the reach of all rivers 

 ancient or modern, my first general impression was, that these an- 

 gular flints were simply the subsided residue of the enormous masses 

 of Chalk that once covered the inferior formations. But this is no ex- 

 planation of the facts ; for if such had been the case, why should there 

 not be as much flint -detritus on the Lower Chalk, Upper Greensand, 

 and Gault, as on the Lower Greensand 1 Again, why should the sur- 

 faces of the three last-mentioned deposits not be eroded in the same 

 manner in which the Lower Greensand is affected? We must therefore 

 seek another origin for this zone of the flint-drift. Looking to the 

 western extremity of the tract of Lower Greensand, where chalk-flints, 

 as above said, alone prevail, I am disposed to suggest, that they were 

 chiefly transported to the hills of sandstone where they now lie, from 

 the recess of Langrish, west of Petersfield, where the chalk which 

 unites the North and South Downs has been extensively denuded in 

 reference to the " hangers " or escarpments of the same formation on 

 the flanks. There, indeed, a very slight elevation separates the sources 

 of the Rother (which, flowing eastwards by Petersfield, falls into the 

 Aran) from those of the river Aire, as fed by its purely Chalk-afflu- 

 ents in the valley of East and West Meon (see fig. 2, p. 353). 



Viewing the extensive denudation of the chalk in this angle, and 

 the heaps of flints which are spread out over Stroud and Steep Com- 

 mons, we may infer that this was the tract whence the debris was 

 translated from west to east ; for in following that direction we have 

 other indications that such was the case. Near Petersfield chalk- 

 flints only, as I said, are met with, and when we look to the west we 



