﻿288 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jlltie 25, 



portion ; a like observation may be extended to all the gravel-beds of 

 the Wealden valleys. The fact may be observed on either side of 

 the gorge at Guildford, along the Valley of the Mole from Dorking 

 upwards ; and it is exhibited in a remarkable manner near Farnham, 

 both descending towards More Park, and in the contrary direction. 

 It was necessary to notice this circumstance here, but its explanation 

 belongs to the history of these valleys subsequent to the date of the 

 gravel-beds. 



The gravel-beds which have been here described are usually found 

 overlying clean surfaces of compact sand and Neocomian clay ; but 

 in the Pease-marsh portion of the valley, where the upper beds of the 

 Weald-clay are exposed, we meet with a bed of compact dark mud, 

 containing vegetable matter, fragments of branches of trees, and the 

 bones of animals (Ox, Elephant) uninjured and lying together : it is 

 evident from this that the condition of the surface before the accu- 

 mulation of the gravel was a terrestrial one, and that this was coin- 

 cident with the occupation of this country by the large extinct mam- 

 malian fauna. 



The brown and red clays which so commonly surmount the gravel- 

 beds will be recognised as the equivalents of those of the London basin 

 area, which hold a like position. They indicate conditions of tranquil 

 deposition, which is all that can be said of them at present. Higher 

 than these last, and influenced by the form of surface, are certain local 

 accumulations of peat and marl, containing the remains of a fauna be- 

 longing to the actual period, such as horns of Deer, and the specimen 

 of Bos longifrons, referred to in a note above. 



The accumulation of chalk-detritus, which has been noticed in the 

 account of Weston- Street section, can be traced up the transverse val- 

 ley to the base of the chalk-range, having frequently the character of 

 subangular fragments. The land shells which they contain suggest 

 further inquiry and research : at present these beds of chalk-rubble 

 have yielded a very poor testaceous fauna compared with that from 

 the uppermost bed of superficial soil. 



It forms no part of the present communication to explain the nature 

 of the Wealden denudation. Sir Charles Lyell still maintains the view 

 that the denuded area was once occupied by an expanse of water of 

 which the escarpments of the chalk were the bounding cliffs, and in 

 immediate juxtaposition to this view, and as proof and illustration of 

 the theory, he describes the gravel-beds at Barcome. It may suffice 

 for the present to state that this accumulation contains the remains 

 of the large mammalian fauna, and that in every respect its history is 

 identical with that of the valley-gravels of the Wey and the Mole. 



