Mr. Webster on the Strata lying over the Chalk. 177 



filled up with clay and loose chalk or marl : over this is another 

 layer of pebbles, and again clay and chalk and fragments of flints; 

 and these follow in succession, but very irregularly, to the top of 

 the cliff, which is at least seventy or eighty feet in height. These 

 materials are in general quite loose, being simply heaped or laid on 

 each other ; but sometimes masses of it are cemented together by 

 stalactitical matter, and when the cliff falls, form blocks of great 

 size and hardness. 



It is impossible to see this cliff without immediately perceiving 

 that it does not owe its existence to original stratification ; but that 

 it is simply the section of an immense heap of fragments of chalk 

 and flints mixed with clay and sand, the whole of which has fit 

 some distant period been subjected to the action of water ; and that 

 it has been thus deposited upon the solid chalk stratum which 

 is now seen below it. 



In tracing this vast collection of water-worn materials, we find 

 that it forms a considerable hill behind the town, and that it joins 

 to the side of the range of hills called the South Downs. 



In Alum bay in the Isle of Wight, however, the stratum imme- 

 diately next to the flinty chalk, and consequently deposited upon 

 it, consists of a white chalk marl without flints. Its nature is 

 sufficiently shewn by its pulverizing with the frost ; and the rains 

 wash it down, so that its situation is marked by a deep hollow. 

 There is some appearance here therefore of a transition of the 

 last portions of the chalk into the clay which succeeded it ; and, 

 the usual rounded flint pebbles over the chalk and the other signs 

 of disturbance being there wanting, it is possible that we have in 

 that place the original succession of depositions. In many parts of 

 Sussex also, south of the South Downs, as at Emsworth, Lavant, 

 Siddlesham, South and North Bersted, Middleton, &c. I found 



Vol. II. z 



