384 
LAMPLUGH : GLACIAL SECTIONS. 
bourhood, the deposit was naturally described as occurring in 
the » Purple Boulder Clay.'* 
But, by the discovery of a lower division — the ' Basement ' 
Clay of Messrs. Wood and Rome — on the beach near the town, a 
little below the cliff -line, Mr. Bedwell and myself were able three 
years ago to prove pretty conclusively that the shelly bed really 
had its place in the ' Basement ' Clay, and not in the 1 Purple.' f 
Since then, occasional breaches in the sea-walls and other acciden- 
tal sections have shown that such is undoubtedly the case ; and 
that, curiously enough, the ' Basement ' Clay rises into the cliff 
to the south of the town just where the sea-defences begin, and 
sinks again to the beach, only a few hundred feet from their 
northern termination, making a substantial show in the cliff 
between these points. 
There is also another cause of geological destruction on this 
coast, which, though working perhaps in a manner not quite so 
obtrusive, is even still more fatal to the sections. I refer to the 
work of that swallower of sections, the sea, which cuts and pares 
through the drift cliffs unceasingly, turning over section after 
section like the leaves of a book ; and when once past they are 
gone for ever — we cannot turn back. And the series of ever- 
changing pictures of these variable beds which is thus presented 
to us, is of no common interest, and would yield, could we but 
note them for long enough, a section in any direction. In many 
parts of the cliffs it is easy to see that in a few years' time the 
section will be very greatly altered, and the old one gone beyond 
recall. Thus is the sea ever changing our old pictures for new 
ones. 
Then again, on the sandy and pebbly beaches the restless 
work of the sea in now and again stripping off, for a time, the 
shingly covering which usually hides the beds, is often of great 
importance to the geologist, for it is wonderful in how many cases 
* Messrs Wood and Rome. Quart. Jour. Geol. Soc. vol, xxiv, p. 149. 
+ Notes on the Bridlington Crag and Boulder Clay. Geol. Mag., Nov., 1878. 
