90 GEOLOGY OF THE ISLE OF WIGHT. 



chain, which bounds the horizon on the south', 

 rises with a bolder sweep, and to a much greater 

 elevation, and exhibits the smooth and rounded 

 aspect, and undulated outline, which are so cha- 

 racteristic of the mountain masses of the white 

 chalk, as to indicate their geological character, 

 even when seen from a considerable distance. 

 The first line of hills consists of freshwater strata, 

 which are superimposed on the eocene marine 

 deposits ; the distant range is part of the chain of 

 chalk downs that traverses the island throughout 

 its entire length, forming on the east the promon- 

 tory of Culver-cliff, and on the west that of the 

 Needles (see the map, PL XX.). 



Geological structure of the Isle of Wight. 

 — Before we land, and proceed to examine par- 

 ticular localities, it will be necessary to take a 

 general view of the distribution of the three 

 formations of which the island consists. It is 

 shown in ligti. 3, (p. 75,) that the Solent and Spit- 

 head occupy a trough or channel from two to 

 seven miles wide-, formed by the London clay and 

 other tertiary deposits which lie upon the chalk. 

 The wells at Southampton, Portsmouth, &c, prove, 

 in the absence of natural sections, that although 

 the strata have undergone great disturbances, the 

 same order of superposition is maintained, as in 



