﻿MURCHISON — FLINT DRIFT OF S.E. ENGLAND. 379 



Before I quit the consideration of the Guildford district, I may 

 say a few more words on the outward slopes of the North Downs*. 

 It does not, however, appear to me that, with the exception of the 

 portion of the North Downs where the chalk is reduced to a narrow 

 and inclined ridge, viz. the Hog's Back and the tracts east and west of 

 Guildford, there has been almost the same amount of shattering of the 

 flints which is observable on the slopes of the South Downs, between 

 Beachy Head and Portsdown Hill. On Guildford Race-course, and 

 particularly above the villages of Merrow and Clandon, the surface of 

 the chalk has indeed been powerfully affected, and millions of loose 

 and half-fractured flints form masses which have been in great measure 

 purged of their original chalky matrix, and are lying in a loosely-aggre- 

 gated state, as if ready to be translated into combes and depressions. 

 Nearer the escarpment the erosion has been still more violent, and 

 deep pits and holes in the chalk are filled up with broken flints and 

 the rubbish, resulting from the abrasion of the tertiary and overlying 

 strata, all tumultuously piled together. Nevertheless, few of these 

 flints present the same sharply-fractured features which characterize 

 those of the Brighton breccia, and for the most part they consist of 

 partially-fractured lumps, the original concretionary form of which is 

 still visible. Again, in descending upon the fine long talus which 

 slopes down from the villages of Merrow and Clandon to the lower 

 country of Send, Ripley, and Woking, the Tertiary clays and sands 

 do not exhibit on their surface anything like that amount of flint- 

 drift which characterizes the southern slope of the South Downs, the 

 angular flints being very small and sparingly distributed, except at a 

 few localities, where they are sufficiently abundant to be sifted out of 

 the sand and used as gravel. 



In following the line of the railroad from Albury to Dorking, I 

 observed angular chalk-flints on the surface of the whitish sands of 

 the Lower Greensand. Near the summit-level of the railroad near 

 Gomshall, they lie in detached patches, though not in the same volume 

 as on the sand-hills of the same age near Petersfield. Now, as no 

 streams have ever descended over these hills of sandstone, since the 

 present configuration of the land and desiccation of the country were 

 effected, I equally refer them to the same agency of drift as that which 

 swept greater volumes of them into the adjacent hollows. 



In some places where the sand passes into a state of sandstone or 

 rock, its surface is seen to have been eroded and its cavities filled in 

 with the flint-debris, just in the same manner as that by which the 

 Chalk has been affected ; and of this Dr. Fitton has cited a good ex- 

 ample west of Dorking in this very tractf. No sooner, however, do 



* I do not profess to have much examined the surfaces of the broad masses of 

 chalk which extend from the North Downs over Kent ; but it is well known that 

 a great portion of their surface exhibits superficial detritus similar to that which 

 I have noticed, as has indeed been well described by Mr. Trimmer (see Quart. 

 Journ. Geol. Soc. supra, p. 34 et seg.). Besides the well-known fossil localities 

 in the environs of London, the remains of Mammoth, Bos Urus, &c, have been 

 found in drift by Mr. Bland at Hartlip near Rainham in Kent, a fact I became 

 acquainted with through Dr. Plomley of Maidstone. 



t Trans. Geol. Soc. Lond. N. S. vol. iv. p. 144. 



