36 
Mr. W. Pengelly on the Red Sandstones, 
time unrepresented by sedimentation. Owing to a luxuriant under- 
growth, the section is small and not so well exposed as could be 
desired ; it is unfortunate, therefore, that for a considerable distance 
east of the " Plantation" the entire country is masked by blown- 
sand. On passing beyond this, however, the Marl and Sandstone 
are found to be in possession of the entire clilf, where they give con- 
firmatory evidence of the correctness of the opinion now advocated ; 
since their Dip agrees, both in amount and direction, with that of the 
Conglomerates in the Plantation," being, in each case, about from 5^^ 
to lO*^ towards S. 20° to 30*^ E. (mag). The Dip and distance fully 
account for the disappearance of the Conglomerate in the eastern 
district without calling in the aid of a hypothetical "fault," more 
especially as the cliff is low on the west, but lofty on the east of the 
blown-sand. I have no doubt, therefore, that all the Red Rocks 
extending from Torbay to the Flat Point (the limits within which I 
at present restrict myself) belong to one and the same period, 
namely the Bunter, or Lower Trias. 
I have no reasons to suppose that this does not apply also to the 
red beds still farther eastward. 
The Red Cliffs waste rapidly : their enemies being Waves, 
Springs, and Atmosphere. 
The northern and southern shores — the extremities — of Torbay 
consist of hard Devonian rocks, chiefly limestone, the central cliffs 
alone being Trias ; and, as the bay is deep and comparatively 
narrow, the waves can only attack the red cliffs in front, that is at 
right angles to their line of direction ; hence their destruction is 
effected by the formation of a series of small holes or cavities, which 
are gradually enlarged into good examples of Caverns of Abrasion ; 
two or more of these ultimately break into one, and this process 
goes on until the weight of the superincumbent mass becomes so 
great and the bases so incompetent, that the whole structure gives 
way and exposes a new cliff to a repetition of the process. About 
Dawlish, on the contrary, the long line of Red cliffs is more exposed, 
and waves assail them from every direction ; hence Caverns are less 
numerous, but insular portions or crags are the results of the 
modification of the operation, and are so many relics of an ancient 
coast line. No such fragmentary masses occur in Torbay. 
Landslips — sometimes on a great scale — are common, especially 
in the Marl ; and appear to be caused by springs. Beautiful 
examples of Slickensides occasionally occur in the fallen matter. 
Watcombe, near Torquay, and other unusually romantic Red 
Sandstone districts are probably attributable to ancient landslips. 
Though the results of " weathering" are much less conspicuous 
and striking than those of waves and springs, the denudation effected 
thereby must be considerable. When composed of fine sandstone 
without " Iron pan," the cliffs, especially when vertical, are lined 
with plates of sand, which vary in thickness from an inch, or more, 
