Geology of NorfoUt. 
457 
the drift, of an arctic climate in the temperate latitudes, of uhic 
so much evidence has recently been collected. 
No sooner had I adopted the theory of gradual submergence 
and gradual denudation, than all the variations of soil which had 
previously perplexed me were seen to be a necessary consequence 
of it. Each fell into its appropriate place ; and in little more 
than a week I was able, from the contour of the surface, and 
even from the representation of it on the Ordnance map, to 
anticipate the nature of the soil which I should find in a given 
locality in the district lying to the north-east of Norwich. As 
I advanced into South Norfolk I was again at fault. Clay 
occurred where I expected to find sand, and sand where I looked 
for clay. Again I repaired to the coast sections at Gorlston, 
and the river sections of the valley of the Waveney, and found 
that these apparent exceptions were likewise a consequence of the 
law, and proved its truth. In East Norfolk, for instance, the de- 
nudation in the deepest valleys had scarcely cut through the sand 
and gravel of the upper drift down to the clay of the lower drift. 
In South Norfolk it had exposed large areas of this clay, leaving 
only outlying patches of the upper drift, and in some places had 
even cut through the lower drift down to the sand of the still 
lower crag, or through that to the chalk. 
Having proceeded in this manner over the eastern half of the 
county, I had done enough to lay the basis of a safe induction, 
and much more than my agreement with the Royal Agricultural 
Society required, and I now passed more rapidly over the re- 
mainder, making wider traverses, and ceasing to map the surface 
variations. The scale of the Ordnance map is the smallest on 
which these variations can be shown ; they vanish when we 
attempt to reduce it. I shall therefore illustrate them by means 
of sections instead of maps. 
The order of succession prevailing among the supracretaceous 
deposits of Eastern Norfolk is shown in Sections I. and II., \\hicli 
also show their relations to the chalk and the lower strata which 
emerge from beneath it in West Norfolk. 
The existence of freshwater beds and of a forest, interposed be- 
tween the crag and the northern drift, which had been described 
by Taylor,* in his work on the ' Geology of Norfolk,' in 1827, 
was denied by Mr. Lyell| in 1829, who regarded the freshwater 
beds as a deposit in a depression of the drift, and the subterra- 
nean forest at Happisburgh, &c., as beds of lignite in the crag, 
between which and the drift he declared himself unable to draw 
a line of demarcation. At that time it was not known that the 
* ' Geology of East Norfolk,' by R. C. Taylor, ]827, 
t ' Principles of Geology.' 
