396 



Farming of Surrey. 



1st. The Tertiary. 



2nd. The Cretaceous, overlying the Wealden. 

 3rd. The Wealden, which is most ancient. 



Commencing' with the most recent deposits the above great divisions may be 

 subdivided according to the character of their various strata. Thus : — 



Tertiary . | ^'-f'^^ , 



I London or Flastic clay. 



Upper chalk, or chalk with flints. 

 Lower chalk, or chalk without flints. 

 Grey chalk marl. 

 Firestone and upper greensand. 

 Gault, or Folkstone marl. 

 Shanklin, or lower greensand. 



Cretaceous ^ 



WeaJden . | ^jj^.^^^ ^^^^^ 



The Bagshot sands are so called from their being extensively developed 

 around the town of Bagshot ; they consist of the upper division on the north- 

 western part of the county, extending from Bagshot Heath on the north to 

 Romping Downs on the south, and stretching on the east nearly to the town 

 of Chertsey — the middle, which underlies the former, and is exposed in belts 

 which extend round the towns of Chertsey, Chobham, Pirbright, &c. — and 

 the lower, which is bounded on the north by the last deposit, and meets the 

 London clay at Walton-on-Thames, Cobham, Esher, and Ripley. The 

 London clay is bounded on the north and west by the Thames and Bagshot 

 sands, on the south by the chalk downs which it meets at Epsom, Clandon, &c^ 

 It also runs in a narrow strip from the west of Guildford to Ash, separating the 

 Bagshots from the chalk. A detached portion of the tertiary formation is also 

 found overlying the chalk ; reaching as far as Guildford on the west, while on 

 the east it occujnes a considerable area, and is extensively developed in the 

 neighbourhood of Walton-on-the-Hill. 



The Cretaceous formation is the most prominent in the county, running 

 through it from east to west. The chalk, its upper division, forms an elevated 

 ridge well known as the North Downs, entering from Kent on the east at 

 Merstham. tiere the downs are of considerable breadth, viz. from 8 to 10 

 miles; they gradually become narrower till they reach Guildford, from which 

 place to Farnhara they form a narrow ridge called the Hog's-back, scarcely 

 broader than the road which skirts its brow. The firestone and upper green- 

 sand which form the second division consist of impure limestone and calcareous 

 sand. The gault is a narrow belt of clay separating the upper and lower 

 greensand. On the eastern portion of the county it widens into considerable 

 importance, while on the m estern it becomes narrow, occasionally disappearing 

 altogether. The last and principal division between the chalk and the weald 

 is the ShanUin or lower greensand, which on the eastern extremity seldom 

 exceeds a mile in breadth, till at Dorking it gradually becomes wider, taking a 

 south-western direction to Haslemere, and averaging in width 5 to 10 miles. 

 The greensand attains a great height at Leith Hill, which is the highest point 

 in the South of England, being 994 feet above the level of the sea. 



It is boped that with the aid of the accompanying map the 

 preceding brief description of the various strata will be found 

 sufhcient as an indication of the position of those districts into 

 which the county is divided by nature, and which will be 



