36 
DILUVIAL DEPOSITS. 
which it has been produced is easily explained, by 
a reference to those natural operations that still 
continue in full activity on our coasts. Were a 
bed of calcareous rubble to be deposited over the 
ruins of the chalk cliffs that are scattered along the 
shore, a collection of materials would be formed, 
corresponding in every respect with those above 
described ; and a vertical section would exhibit 
an appearance precisely similar, namely, a stratum 
of solid chalk at the base ; then a layer of sand 
and of shingle ; and, lastly, a heap of displaced 
chalk, surrounded by calcareous diluvium. In 
corroboration of this opinion, it may also be re- 
marked, that while, in general, the variations ob- 
servable in the colour and composition of the 
Elephant hed are nearly horizontal in the circum- 
stances under discussion, they are no longer con- 
formable to the subjacent deposit, but rise over the 
heaps of chalk rubble, as in the section page 34. 
These interspersions of pure chalk are frequent in 
other parts of the bed, but the present example is 
one of the most remarkable. 
Proceeding eastward, at the distance of two 
miles and a half from Brighton, the cliff is com- 
posed of the Upper chalk, to the extent of three 
hundred yards. This remarkable change in the 
structure of the cliff has evidently been occasioned, 
partly from the destruction of the diluvial deposits 
by the inroads of the sea, and partly from a jiro- 
jection of the chalk, which formed their ancient 
boundary ; for there appears to have been but little 
correspondence in the sinuosities of the ancient 
and modern shores. An abrupt recess marks this 
