174 SHEPPAED AND STATHER : GLACIAL DRIFTS OF HOLDERNESS. 
Hessle type, and contains few boulders, which are generally- 
of small size, and of which a very large proportion consists of 
Cheviot rocks. This boulder clay is surmounted by a very 
loose, earthy material, containing a greater proportion of pebbles, 
and appearing to be redistributed drift. This in all probability 
has been washed from the top of the hill, which is now entirely 
denuded of boulder clay. 
The gravel varies very much in character ; in places it is 
exceedingly fine, consisting almost entirely of chalk and shell 
fragments, with a little sand ; in others it is coarse, and partially 
cemented together either by oxide of iron or by Hme. Iri some 
parts of the gravel beds of sand occur, which are of a very fine 
character, and contain a few shell fragments. The mammalian 
remains are usually found in the coarse gravel. 
The pebbles contained in the gravel include a great variety of 
rocks common to the east coast drifts, including augite- syenite 
and rhomb-porphyry from Christiania, basalt and Carbon- 
iferous Limestone from Teesdale, and Liassic, Oolitic, and chalk 
pebbles and fossils from the north-east coast of Yorkshire. 
A few Scottish rocks can also be detected. Many of the chalk 
pebbles are bored by Saxicava and Pholas, the shells of which 
are frequently in position in the crypts. 
The whole of the evidence contained in the new section, 
as read by the present authors, seems to indicate that the gravel 
is morainic in character, and has been disturbed and altered 
by an oscillating ice front, which probably on more than one 
occasion over- rode the moraine. This was after the deposition 
of the basement boulder clay, which occurs at the base of all 
the Holderness drifts. Borings at Kelsey Hill prove a boulder 
clay under the gravel, and whilst this is in all probability the 
" basement " clay, it is of course difficult to decide by a core from 
a boring. 
We see no evidences of a mild inter-glacial period in this 
very excellent section. 
We beg to thank the . Divisional Engineer of the North 
Eastern Railway Company, Mr. Edward Smith, and his staff, 
