Proceedings. Ill 



belongs ; and the Folkestone Sands, whicli are of much 

 cleaner character than the other divisions. We see them 

 here in Mr. Pym's pit, and various small sections ; and I 

 think its being cleaner and generally of smaller grain may 

 show that it was formed at a greater distance out to sea than 

 the Sandgate and Hythe Beds, which contain pebbles and a 

 large mixture of clays and earthy limestones from material 

 most probably brought down by the river. In some of these 

 clear yellow sands, on the spot where the Oxted Station on 

 the new Croydon and East Grinstead Line is situated, and 

 which, I believe, belong to the Folkestone division, I noticed 

 last spring many pieces of drift-wood interspersed through- 

 out the section some six feet or so deep, as if the current 

 which bore them thither had continued to flow for some 

 time, long enough to allow of sand to accumulate for about 

 six feet. This wood had been decayed all except the outer 

 part, which was converted into a crust of oxide of iron. In 

 some cases the interior appeared to have been replaced by a 

 brown fibrous mass of the same material. 



Now we have travelled over the ridge of hills, and descend 

 into Holmesdale, at the bottom of which we come upon a bed, 

 the Gault, which exhibits very great differences in several 

 respects to those we have considered. First, its mineral 

 character differs, as it consists of a dark blue or slate-coloured 

 clay. Next, the assemblage of fossil remains is found to have 

 altered. But the crowning distinction of all consists in its 

 showing that a break in time has taken place between the 

 last deposited layer of the Lower Greensand and the existence 

 of the clay-bottomed sea in which the Gault was formed. 

 And in this another principle of Geology is well displayed — 

 that is, Upheaval and Denudation. Where we get a section 

 showing where the Gault lies on the Folkestone Sands we 

 see that there is no merging of the one into the other, as was 

 the case between the Wealden and the Lower Greensand, but 

 the top beds of the sand have been worn away. Now this 

 could not have taken place at the sea-bottom, as there there 

 could have been no agency capable of effecting such a wearing 

 away of the sandy beds ; so we come to the conclusion that 



