NEW RAILWAY-CUPTING AT GUILDFORD. 611 
denoted by the arrow, that the movement of the mass was from KE. to 
W., or down the line of present shallow valley or combe from 
Warren Farm, near the top of the Downs, the portion a’ having 
been forced out from a into the watery sands, when perhaps 
in a frozen state, the upper surface of the flints, 6’, having at the 
same time been forced onward and separated from ). ‘There is also 
a yery different condition of things indicated by the great contrast 
between the extremely coarse nature and bedding of the drift 
resting on the angular chalk-rubble and the finer angular loamy 
beds that cap both this and the older sands (vide section at 
London Road, figs. 5 & 6, and fig. 1). 
Through the two phases of old terrestrial surface there are in- 
dications of quite a temperate climate, of the existence of great 
Mammalia living through both, and of a probable connexion with the 
continent of Europe, at least during the first phase. The change to 
the cold era we can imagine to have been gradual, killing off by 
degrees the large pachyderms and the associated fauna, whose re- 
mains are found invariably in the lowest beds and, as in the Tilling- 
bourne, lying among the stools of the trees that grew on the old 
surface there. This surface was eventually covered up and perhaps 
destroyed by the valley-drift, which to a certain distance and level 
is found on the surface of all the formations running parallel with 
the North Downs on both sides of the ridge. I cannot see that it is 
necessary to introduce any forces indicating such violent action as 
the breaking up of the surface, or even any great alteration of 
general level. ‘The steady denuding action of land-ice appears to me 
quite sufficient to have scoured and planed the surface of the Chalk 
and neighbouring formations as we now see them, and to have 
distributed and carried the deposits of flints to the distances at 
which we now find them. ‘There seems to be good evidence too, or 
even proof, that, for a part of this cold period at least, there was a 
complete change in the drainage of the country for a considerable 
distance east and west, which might have been caused either by the 
partial damming up of such gorges as those of the Wey and Mole, 
or by a slight elevation on the north, or a depression south, on the 
English Channel area. Such a late depression is indicated on the 
Sussex coast; and Sir Roderick Murchison, in the following para- 
eraphs, considered such to have taken place in Kent on the Med- 
way *:—‘ The loam-drift with flints extends indeed all down the 
banks of the Medway to Maidstone, and, occasionally spread over 
flats, is exposed near Yalding Station, capping a small elevation of 
Lower Greensand (Neocomian).” ‘The arrangement of the drifted 
material also shows that the waters, whatever they were which 
translated them, acted in an opposite direction to the present 
Medway; for in proportion as you approach to Maidstone and the 
North Downs, the fragments of flint become larger and much more 
abundant ;” and again, at the conclusion of a paragraph on p. 387, 
with regard to the valleys having assumed their present form prior 
* Quart. Journ. Geol. Soe. vol. vil. pp. 882, 383. 
