62 
(Scale 150 feet to the inch.) 
Fic. 2.—-Cliff section west of Wood Hill, Runton. 
ee 
Clement Reid—Glacial Deposits of Oromer. 
s Do 
S 
a 
SE 
LEN. 
Vay 
D Boulder-clay with masses of sand, 
C Undisturbed Pre-glacial Beds. 
B’ Chalk Boulders. 
B Chalk in place, 
A Level of mean tides. 
It is very possible that at the time the 
contortions were being formed, the Pre- 
glacial beds were frozen into a tough sand- 
stone, in which state, owing partly to the 
absence of joints, they would be more un- 
yielding than the majority of ordinary rocks. 
The shearing force or lateral pressure 
would not, however, act uniformly, for 
wherever there was a slight hitch the un- 
derlying beds would be ploughed up and. 
contorted, as in the case of the Trimming- 
ham Chalk. A little further pressure and 
the loop would be sheared completely off, 
driven up the gentle incline, and formed 
into a detached boulder such as we find at 
the base of the Boulder-clay near Runton 
(Fig. 2). That this is the right explana- 
tion of the mode of transport of the Chalk 
masses seems to be borne out by the fact 
that they always correspond in character to 
the chalk of the immediate neighbourhood, 
and that they disturb the overlying deposits, 
which would not be the case if they had 
been brought by icebergs. It is also singu- 
lar that none of the transported masses are 
found beyond the district where the chalk 
is near the sea-level, and where it is occa- 
sionally ploughed into by the Boulder-clay. 
On the iceberg theory it is impossible to 
account for the non-occurrence of Chalk- 
boulders south of Trimmingham, and in the 
neighbourhood of Norwich and Yarmouth. 
From the readiness with which they can 
be identified, the chalk masses have long 
been known; but it is evident that if the 
above explanation be correct, we ought also 
to find masses of the older boulder-clays 
and pre-glacial beds in the Contorted Drift. 
Such masses are to be found, though from 
their less striking contrast they are not so 
conspicuous. 
On the west of Cromer, and close to the 
town, there is a transported mass of peat 
and laminated loams, just such as could 
be obtained from the top of the Woman 
Hithe or Runton black freshwater bed and 
the overlying Leda Myalis Bed. Of course 
I do not mean that it came from that. 
locality, but that the beds are probably 
of that age. . 
