COLE : DESCRIPTION OF PHOTOGRAPH OF BOULDER CLAY CLIFFS. 443 
II. Composition of the Section. 
In the foreground is a marine platform of alternate beds of grits 
and limestones, which form the lower passage-beds between the Lower 
and Middle Calc. Grits of the Middle Oolites. Similar beds are con- 
tinued at the base of the stratified portion of the section. In the 
centre is the Middle Calc. Grit six feet thick. These beds, as will be 
noticed, rise slightly towards the east, but the real dip is to the 
south-west. It must be remembered that the view before us is that 
of a promontory, and that we are looking at the south side ; imme- 
diately to the north is the sea, at a distance of 150 yards, but with 
very different cliffs opposed to it. There the beds, which in the 
photograph have only an elevation of some eight to twelve feet above 
sea-level, rise up in cliffs thirty to forty feet above sea-level, so that 
the dip is considerable. 
Immediately upon the stratified beds rests about a foot thick of 
rubbly-decayed Oolitic conglomerate, very similar to what may often 
be seen on the top of the Chalk. It marks the old land surface before 
the deposition of the Boulder Clay, and shows the denudation that 
was then going on by frost and snow. The main body of the cliff, 
which is nearly one hundred feet in height, is composed of Boulder 
Clay, and probably no finer section can be found in the kingdom, for 
the clay is to a great extent homogeneous, that is to say, there is an 
absence of pipes of sand, which, in so many instances of Boulder 
Clay cliffs, allow water to percolate the mass and destroy it piece-meal. 
Here the cliffs are remarkably firm and consistent, and the clay 
seldom gives way to mud. Numerous boulders will be observed 
sticking out from the face of the clay, one especially, to the left, 
composed of sandstone, which will soon be undermined and fall to 
the beach to join the many which have already found there a temporary 
rest. 
III. Origin and Age of the Boulder Clay. 
It is generally conceded by geologists that Boulder Clay is the 
product, not of icebergs or ice-floes, but, of land-ice, or glaciers. 
Into the arguments pro and con it is not necessary here to enter. As 
a matter of fact Boulder Clay, of great thickness, is found all along 
the Yorkshire Coast, from Redcar to Kilnsea on Spurn Point, filling 
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