246 
LAMPLUGH: GLACIAL SECTIONS. 
The Basement Boulder Clay. This division was only touched 
in the deepest drains just before reaching the Harbour, but was cut 
into in carrying the outfall pipes across the Harbour and over the 
South Sands to low-water mark. It was of the same patchy nature 
as in the former sections, the cuttings in the Harbour showing a 
large proportion of sandy wash in irregular masses, not however, 
containing shells, save as worn fragments. 
The Laminated Clay, No. 4 of former sections, true to its rule 
of not attempting to rise above a certain level — that of high tide — 
was not found in these sections, except on the beach. 
Concluding Notes. — Following the plan of my former papers, I 
will now briefly record the deductions I have drawn from the facts 
observed : also as in former years, concentrating attention chiefly 
on one point, which on this occasion shall be The Freshioater Gravels. 
I commenced working on the Sewerby Gravels, as on the 
Hilderthorpe Sands, with the idea that they were marine, but during 
the course of my investigations the conclusion has been forced upon 
me that they are freshwater ; and the knowledge gathered from the 
drains has strengthened me in this view. 
In the absence of contemporaneous organic remains in either 
bed there is no direct proof of this, but the indirect evidence is strong. 
Before dealing with this, it will be well to show on what 
grounds T conclude that the Sewerby Gravels, the Bridlington High- 
level Gravels, and the Hilderthorpe Sands are lateral extensions of 
one and the same bed. 
The connection between the Bridlington and Sewerby Gravels 
has already been partially traced. Their general appearance ; their 
respective positions relative to the Boulder Clay and Chalk; the levels 
at which they occur ; the character of the Chalk-fragments contained 
in them ; and the way their pebbles decrease in size as we leave the 
steep chalk slopes, are all strong proofs of their intimate relationship ; 
and that the Hilderthorpe Sands form their southerly extension rests 
on evidence equally convincing. 
The relative position of the Sands to the Boulder Clay below, 
and to the marls and fine chalky-gravel above ; the tendency of the 
sands and clays to pass into, or include streaks of gravel with small 
