AUSTEN TERTIARY DEPOSITS OF THE SUSSEX COAST. 63 



in lines. The differences to be observed in the brick-earth of the 

 coast-sections, as compared with that in the pits about West Ilampnet 

 and inland, are such as result from the nature of the deposit. 



Along the present coast-line the brick-earth contains abundantly 

 and throughout small concretions of iron-ore. There are occasion- 

 ally also intervals of mud or silt, with a breadth of from 40 to 50 

 feet, which look much like the old courses of very sluggish waters ; 

 but, after very diligent search, I was unable to find any shells, either 

 in the brick-earth or in the silt. The small seeds of some plant are 

 not uncommon. 



The brick-earth nearer the hills contains Helices and Succinece, as 

 usual. The beds are much thicker, and seams of sand also occur. 



It may perhaps appear to some persons in examining the sections 

 on the Sussex coast, that at certain spots the brick-earth passes 

 down into the detrital accumulation next beneath it. Such appear- 

 ances are very common in beds of all ages. In this case, the two 

 sets of conditions under which the deposits were formed render any 

 such supposition wholly out of the question ; and the apparent 

 passage is owing to the circumstance, that the fine sediment of the 

 brick-earth deposit found its way down amongst the coarser gravel as 

 it began to collect over it. In places where the uppermost of the 

 underlying beds consists of fine sea-sand with shells, and only a few 

 pebbles, the line which separates the two accumulations is clearly 

 marked. 



With reference to the conditions under which the brick-earth has 

 been formed, it may be stated generally, that it is a subaerial de- 

 posit. In every instance, in every country, it partakes of the nature 

 of strata immediately contiguous. Its great thickness in places, as 

 well as the abundance of the remains of certain land-shells now 

 scarce, indicate conditions somewhat different to such as obtain here 

 now. Its most usual character is that of the wash of a terrestrial 

 surface, under a far greater amount of annual rain-fall than we have 

 at present. 



5. Equivalents of the Brick-earth. — From the subaerial conditions 

 under which the brick-earth was formed, here, as elsewhere, its equi- 

 valents vdll assume every form which materials acted on by meteoric 

 or alluvial action can possibly take ; the only characteristic of those 

 accumulations consisting in their larger scale, as compared with 

 similar ones in the present time. 



On approaching the chalk-range, the brick-earth passes into a 

 calcareous marl, next into an accumulation of small rounded particles 

 of chalk, and so finally passes into the mass of rubble or talus which 

 is found at the base of the chalk- slopes. 



The alluvia of the large rivers, with their more torrential character, 

 which are to be seen in all the valleys which open out from the 

 Wealden area, are also partly referable to the same conditions ; for 

 the Wealden district being physically the same then that it is at 

 present, both for extent and elevation, could only have supplied 

 more copious streams under the supposition of a much more abun- 

 dant rain-fall. Some of these phsenomena, however, as regards the 



