TRANSACTIONS OF SECTION C. 751 
From this point as far as the west base of Eastcliffe, the cliffs are composed of 
the Middle Chalk Nodular, and White, No. III, rising on the west to 490 + O.D., 
and plunging down to the east to a depth of 180—O.D, at St. Margaret’s. At its 
base is a hard nodular iron-stained layer, the Grit-bed of Price, forming a con- 
spicuous band in the English and French cliffs. The three upper members of the 
section constitute the Upper Chalk, out of which the cliffs between Dover and St. 
Margaret’s have been carved. 
All these strata dip steadily to the east at an inclination of about 1 in 72. 
On the French side, in the cliffs between St. Pot and Sangatte, the Lower and 
Middle Chalk of the English section emerge from the sea with physical characters 
the same, and the thickness practically also the same. They dip also to the east, 
but at a higher angle. 
The French survey of the sea bottom in the Straits for the purposes of the pro- 
posed tunnel proves that the Lower and Middle Chalk are perfectly continuous 
and constitute the sea floor, the sea in the line of the tunnel being 192 feet in depth 
at the deepest point. 
It is obvious that the geological structure of the Straits of Dover offers great 
facilities for the construction of a tunnel, which would descend at an inclination 
of 1 in 70 or 80 on the English, sweep under the Channel and rise with the 
strata on the French side, if it can be made in an impervious stratum which cannot 
be traversed by the sea water under high pressure. The only stratum satisfying this 
condition is the Lower Grey Chalk, and especially the lower and more clayey 
horizon overlying the Glauconitic Marl. 
A careful examination also of the cliffs proved that the faults, mostly small and 
insignificant, do not become water passages at this place in the section, because 
they become blocked with clay. There are no springs at this horizon in either the 
English or the French cliffs. 
These considerations led the Channel Tunnel Companies to sink the shafts at 
the Shakespeare Cliff and at Sangatte down to this horizon, and to make their 
drifts on the English side 2,300 yards long, and on the French more than a mile, 
assing diagonally away from the shore under the sea. The selection is amply 
justified by their experience. On the English side the faults visible in the Shake- 
speare Cliff were traversed, and yielded a slight oozing of water, which was stopped 
by rings of iron tubing. These rings were afterwards removed and the faults 
were found to be perfectly water-tight. The water in the French shaft comes from 
the fault intersected at a point considerably above the level of the drift, which 
here also traversed small water-tight faults. 
The chalk is here soft enough to be easily cut by Colonel Beaumont’s machine, 
and hard enough to stand without lining. Five years’ exposure has not sensibly 
affected the surface of the drift, which remains as fresh as the day when it was 
made. The geolovical conditions are therefore peculiarly favourable for the con- 
struction of a submarine tunnel at the bottom of the Chalk, and do not present any 
engineering difficulty. 
2. On a Proposed New Classification of the Pliocene Deposits of the East of 
England. By F. W. Harmer, F.G.S. 
The term Red Crag, including, as it does, beds differing considerably in age, is 
vague and, when we attempt to correlate the Hast-Anglian deposits with those 
of other countries, inconvenient ; the Scaldisien zone of Belgium, with its southern 
fauna, for example, representing one part of it, and the Amstelien of Holland, in 
which northern and even arctic mollusca are common, another. 
It seems desirable, therefore, while retaining it for general use, tv adopt for its 
‘various horizons some more definite and distinctive names. 
The upper Crag deposits arrange themselves geographically, in horizontal rather 
than in vertical sequence, assuming always a more recent as well as a more boreal 
character as we trace them from south to north. They are the littoral accumula- 
tions of a sea which was from time to time retreating in a northerly direction. 
