36 
LAMPLUGH : GLACIAL SECTIONS. 
I was for some time at a loss to account for che discharge of 
such a strong volume of water of fine quality from an apparently 
isolated and insignificant seam of gravel ; but I am now of opinion 
that the water is derived from the chalk, either by the inland 
continuation and unconformable overlap of the gravel, for which 
the cliffs north of the town yield confirmatory evidence, or by 
the direct upward rise of the water through some gap or pervious 
place in the basement clay. 
Water is shed copiously between tide marks along the range 
of chalk cliffs on both sides of Flambro' Head, 
The Basement Clay (5). Of this boulder-clay I have given 
a full description in the Geological Magazine for December, 
1881, p. 535, and need therefore give no further account of it 
here, I may mention, however, that I am at present trying to 
make a full collection of the older rocks which occur as boulders 
in such immense variety in this clay, with the hope that it may be 
possible to determine the source of many of them ; and I shall be 
glad to send specimens for examination to anyone who thinks he 
can identify any local igneous rock known to him which may 
occur amongst them. 
It will be observed that gravels containing a large proportion 
of chalk occur at three horizons in this section : — 1st, above the 
sand and clay series (No. 2 of section) : — 2nd, above the Purple 
Clay (26) : — 3rd, below the laminated clay. To these may be 
added the stratified boulder clay band f3cj, which if washed 
would yield a similar gravel. 
I think this a point worth attention, as these gravels indicate 
the constant recurrence of an exposed chalk surface in the neigh- 
bourhood during the deposition of the boulder-clays ; — a condition 
to be borne in mind when considering the origin of the clays. 
The chalk wold extends in a curved sweep about a mile to the 
north and west of the sections. On the promontory of Flambro' 
Head there are some gravels containing much chalk and others 
