S. V. Wood,jun. — American and British Surface-GeoJogy. 549 
appears to me now to throw a clear light on this case. This cutting 
was made through the north side of the Yare Valley, and in it the 
chalky clay was exposed with the Middle Glacial sand containing 
its shell-bed under it on the upper part of the valley side ; but lower 
down the whole of the clay had been ploughed out, and the sand 
was all twisted up with the Lower Glacial (Bure Valley) sand, on 
which, after the first excavation of the valley, it had been deposited. 
In the valley below the chalky clay inay still be seen in section 
resting on the glaciated chalk floor of the valley, and it is clear that 
we have here an illustration of what glacier-ice produces when moving 
over clays and sands, viz. their destruction in part and the twisting 
of the rest with the soft beds on which they repose . 1 A similar 
feature of ice plough was afforded (some years ago when the cutting 
had been fresh scarped on one side) by the railway cutting at the 
East Suffolk Railway Junction, Ipswich, in the Gipping Valley. If 
such features were exhibited generally over the plateaux through 
which these valleys are cut, we might explain tliem merely by a 
general advance of the ice ; but there has been no such ploughing 
over the plateaux, as the numerous inland pit sections over them and 
the continuous sections of them which the cliffs north and south of 
Lowestoft afford, show in the case of the Yare Valley most clearly. 
Thus the succession of events in East Anglia was, first the deposit 
by marine agency over a floor formed of Chalk, Lower Tertiaries, 
and Crag, of the Lower Glacial series in considerable thickness ; 
next the excavation of the valley-troughs (whether subaerially or 
subaqueously may be here left out of consideration), into which, as 
shown by Mr. Härtner and myself, the Middle Glacial sand was 
bedded and covered by the chalky clay ; and then, while the chalky 
clay was still in progress, these deposits were elevated into land, so 
as to form the coast beit which I have described. This beit was 
pressed on its western side by the great body of ice which, having 
passed over Lincolnshire, occupied the fen, and from whose mass the 
tongue-like glaciers passing through some of these valleys to the sea 
went off and formed the means by which the land-ice escaped ; and 
these by their ploughing produced that subsequent denudation of 
those valleys, and gave rise as they receded to those deposits of 
morainic clay which we find in them, resting upon glaciated chalk, 
which were so long puzzles to me. In the case of the smaller 
valleys as well, as in those lateral to the few main ones through 
which the glacier tongues passed, the patches of chalky clay which 
occur in their bottoms appear to have been produced by the drifting 
into them of floe-ice freighted with sheets of the morainic material. 
The action of this inland-ice upon the western parts of Norfolk and 
Suffolk may also be traced in the abrupt termination in these parts 
of the counties of the Lower and Middle Glacial, as though both had 
1 Where this cutting was carried through, sand had rested on sand, viz. the 
Middle Glacial on the Bure Yallev beds ; hut a pit ahout a quarter of a mile west, 
of old date. showed the Middle Glacial sand resting on the Contorted Drift, which 
in that neighbourhood is uncontorted. The valley plough referred to in the text 
had here contorted the two together, and so given rise to this exceptioual feature. 
