434 
CLARK : GLACIAL SECTIONS. 
fairly satisfactory evidence of the beds contained in the area. 
These beds could not be followed on the surface, which for most 
of the winter was 6 or 8 inches deep in clay mud. 
From these data the above named plan has been drawn up to 
indicate the various beds. There are yellow glacial sands (1 and 
5) ; red (or purple) and black boulder clays (3 and 4, 7 and 8) ; a 
pure, black glacial clay (2 and 6) ; pebble beds, red alluvial sands 
(9) ; red and black laminated clays (10 and 11). Sections at greater 
depth are indicated by deeper shade. Altogether the mixture of 
substances, and the regular strike of the beds (as if pressed by 
some enormous mass, moving up from the S.W.) makes the whole 
area one of singular interest. Of these beds, the red sands and 
laminated clays in the S.W. part are post-glacial, forming a thin 
skin, beneath which the trenches frequently show the glacial beds. 
The S.W. corner is nearest the original level, perhaps only 3 feet 
below it, whilst the N.E. corner and, indeed, a full third of the 
area, must have been 12 feet below. 
Turning, however, to the vertical sections, especially as 
disclosed in the cellars, the interesting character of the beds is 
more obvious. The same beds are cut across again and again by 
the parallel sections. Their rise and fall and mutual relations are 
easily followed. In the case of a sand-bed, (PI. XXIII., Fig 3) it 
appears as if its convolutions were intersected two or three times, 
from 1 to 6 sections of each fold having been exposed, All these 
beds lean towards what may be termed the central axis of the 
system.* Of this we have the first sign in a flat dome of black clay 
under red clay on the S. wall of the N. platform-cellar, still better 
seen on the N. side of the mid platform-cellar, where it is 21 feet 
long and 2-J feet high. Proceeding S.E., along the strike, we 
meet it again on the S. side, the cellar being 28 feet wide. The 
dome of black clay is now cut off above, where it is 9 feet broad, 
the base having increased to 36 feet. Beneath it there now 
appears a second dome of pure yellow sand, which is first seen at 
* This cau be easily picked out running N.W. from the S.E. corner of Plate I. 
