318 HARMER : THE PLEISTOCENE DEPOSITS OF EAST ANGLIA. 
the former deposit rests on the Chalk, such denudation having, 
in my opinion, destroyed all trace of it further to the north. 
There are certain laminated beds at the base of the Cromer 
cliff section, however, which have been regarded by some ob- 
servers as of Chillesford age,* and by others as passing horizontally 
into the Weybourne Crag. I am inclined to agree as to the 
last point, but not as to the first. 
The slight local submergence of the Weybourne stage was 
followed by another elevation which, during the deposition of 
the so-called Forest-Bed, reintroduced estuarine conditions into 
North-east Norfolk, but the estuary of the great southern river 
then lay somewhat further to the east than during the Chillesford 
stage. 
The Arctic freshwater bed of Mr. Clement Reid, with Salix 
polaris and Betula nana, which overlies the Forest-Bed series 
(the fauna, as well as the flora, of the latter pointing to the 
existence of a temperate climate), indicates the advent of the 
Great Ice Age, heralding the approach of the North Sea ice 
to the Norfolk coast ; the arctic freshwater deposit is, in its 
turn, overlain in the coast section by Glacial deposits, the Cromer 
Till, and the sands, clays, and gravels of the Contorted Drift. 
These were placed by Wood in his Lower Glacial division of the 
East Anglian drifts.! Inland, the Norwich brickearth, into 
which the Contorted Drift seems to pass horizontally, rests on 
pebbly flint gravels, the distribution of which is shown in Fig. 3. 
These may represent the littoral accumulations of the North 
Sea at this stage, or possibly the detritus of streams issuing 
from the ice foot, not far distant. Considerable destruction of 
the Chalk must have been then going on. 
We are indebted to Mr. Reid, who spent some years in 
specially investigating them, for our best account of the Glacial 
* Mr. Clement Reid takes this view. In the " Pliocene Deposits of 
Great Britain," p. 139, 1890, he considers the Weybourne Crag as equivalent 
to the upper part of the Chillesford Clay. More recently, in the Trans. 
Norf. and Norw. Nat. Scty., Vol. vii., p. 295, 1902, he shows Chillesford 
Clay (?) as resting on Weybourne Crag. Tellina balthica, the characteristic 
shell of the latter, does not occur, however, at Chillesford. 
t Wood's division of the East Anglian drifts into Lower, Middle, and 
Upper, is probably of local application only. 
