VALLEYS ON THE EAST OF LYME AND OF SIDMOUTH. 239 
VALLEYS OF DENUDATION, AND DILUVIAL PEBBLES 
IN DORSET, DEVON, WILTS, AND BERKS. 
Some of the best examples I am acquainted with of valleys thus 
produced exclusively by diluvial denudation occur in those parts of 
the coasts of Dorset and Devon which lie on the east of Lyme, and 
on the east of Sidmouth; and the annexed views and map will 
illustrate, better than any description, the point I am endeavouring 
to establish. In passing along this coast (see the Map and Views, 
Plates XXV. and XXVI.) we cross, nearly at right angles, a con¬ 
tinual succession of hills and valleys, the southern extremities of 
which are abruptly terminated by the sea; the valleys gradually 
sloping into it, and the hills being abruptly truncated, and often 
overhanging the beach or undercliff, with a perpendicular precipice. 
The main direction of the greater number of these valleys is from 
north to south; that is, nearly in the direction of the dip of the 
strata in which they are excavated: the streams and rivers that flow 
through them are short and inconsiderable, and incompetent, even 
when flooded, to move any thing more weighty than mud and sand. 
The greater number of these valleys, and of the hills that bound 
touched, merely because the excavation did not cut deep enough. The coast of Dorset 
and Devon exhibits a case of this kind very beautifully; and with the greater distinct¬ 
ness, because the beds, which are there intersected, by valleys nearly at right angles to 
the coast, are so different from each other, and so unlike in appearance (chalk, green 
sand, oolite, lias, and red marl), that there is no difficulty in tracing them, and no doubt 
as to their former connexion. The author’s paper on this part of the coast, which he 
has subjoined in an Appendix, is accompanied by a map and explanatory views, and 
illustrates very clearly this important step in his argument .”—Edinburgh Review, No. 77. 
pp. 227, 228. 
