ars 
Clement Reid—Glacial Deposits of Cromer. 
A reference to the section 
will show that the contortion 
must have been caused by 
lateral pressure directly on- 
shore, that is to say, from the 
north-east; and that the dis- 
turbance, however caused, 
affected the whole thickness 
of the cliff, as Lyell first 
pointed out. The disturbance 
of the solid chalk extends to 
a distance of three-quarters 
of a mile along shore, and 
the thickness of the chalk 
and drift affected must, when 
we allow for denudation, be 
upwards of 300 feet. 
If we now consider what 
an ice-sheet advancing over 
the North Sea could effect, 
we find that, after flowing 
over a tolerably level sea- 
bottom, it would at last abut 
against the rising land of 
the Norfolk coast. The ice 
would then drive before it 
a vast mound of the loose 
sands and _ Boulder-clays, 
exerting an enormous shear- 
ing force, so that the junction 
of the Contorted and of the 
Pre-glacial beds would be 
in reality a nearly hori- 
zontal ‘fault-line.’ This I 
think accounts, firstly for the 
undisturbed Pre-glacial or 
older Glacial beds beneath 
violently contorted beds, 
secondly for the sharp line 
of junction which can gene- 
rally be fixed to an inch, and 
thirdly for the fact that the 
‘most complicated contortions 
are usually near the base, as 
the upper part would be 
merely thrown into a sys- 
tem of folds, while friction 
would cause the beds at the 
base to be full of small dis- 
turbances. 
Fic. 1.—Section at right-angles to the cliff through the westerly chalk bluff at Trimmingham. (Scale 200 feet to the inch.) 
i) 
Git 
77 
‘ea 
| 
61 
seen and measured by the author. 
G The Beds in section above white line were 
* Chalk seen in situ on beach here, 
D Second Till. 
F Contorted Drift. 
E Sands. 
A Level of low-water spring tides. 
C Pre-glacial laminated clays, ete. 
B Chalk, with sandy bed at + 
