2^2 
which beds of gravel and sand were deposited, which, on the 
subsequent thawing of the ice, sunk into its place ; horizontal 
beds of sand and clay being afterwards accumulated over 
the whole. 
The contortions which occur in the fine-grained, thin- 
bedded, sandy clay are, on the whole, perhaps the most 
striking. The general character of those in it, as well as 
in other deposits, is that at the bottom are perfectly undis- 
turbed beds, and over these, the junction being quite sudden 
and distinct, are others of precisely the same nature, but 
bent and twisted, in the most remarkable manner, into very 
complicated and intricate curves. The surface of the con- 
torted beds has then been reduced to a level, the pro- 
jecting parts removed, and other undisturbed horizontal 
ones accumulated over them. 
We are hence compelled to admit that no disturbance 
from beneath could have given rise to the contortions, for 
in that case the beds below would have partaken in the 
movement. Neither could any acting since the accumulation 
of the upper beds, or else they could not have remained 
horizontal. These facts, and especially the connexion of 
the disturbed part with those on each side which are not 
so, will be best seen from the very limited case shown in 
Mg. 2. At the bottom is a mass of thin-bedded fine sand, 
quite undisturbed ; but at the upper part, where of precisely 
the same nature, even ripple marks being traceable, the beds 
are bent up into great curves. As will be seen, the con- 
torted beds pass on the left side into perfectly undisturbed 
ones, whilst, on the right, they end, more or less abruptly, 
in a mass of fine sand, showing little or no trace of strati- 
fication, but farther on becoming regularly bedded. 
Now such a case as this, I think, proves most clearly that 
there has been some force applied on the right hand side, 
which broke up the beds and pushed them along into curves 
towards the left ; and it appears to me that an iceberg is 
