18 
W. Pengelly on the Red Sandstones, 
" Pebble Bed " or *' Popple Bed " very correctly indicates its 
character. Being thus a loose aggregation of materials, it is not 
surprising that the bed yields to the action of denuding agencies 
more rapidly, perhaps, than any other member of the Triassic 
series ; and when it is remembered that fragments of the associ- 
ated Marls and Sandstones are very soon converted into mud or 
sand, we have an explanation of the facts that the waste of this bed 
has furnished the great bulk of the materials which compose the 
extensive modern beach at Budleigh Salterton, and that the supply 
is so liberal and continuous as to allow of a very large deportation* 
partly by man for road making, and partly by the waves to assist in 
the formation of beaches towards both the east and the west. The 
quartzite pebbles have been found as far east as Pinnay Bay, where 
they are still polished ellipsoids. A journey over nearly twenty 
miles of rocky coast succeeds in reducing their dimensions, but not 
in changing their forms ; all that travel could do for them in the 
latter particular had been achieved by the old Triassic waves. 
The upper and lower surfaces of the bed are well defined, and 
conform strictly to the overlying and underlying strata, so that, as 
a whole, its dip is precisely that of the Trias of the district ; but 
all that can be said of the pebbles is that, perhaps, the longest 
axes of a majority of them have approximately the same dip as 
the entire bed ; the exceptions to this, however, are so very 
numerous that the materials can scarcely be said to have a stratified 
arrangement. 
Lenticular patches of fine red sandstone are somewhat nu- 
merous in the bed ; some of them are estimated to be about four 
feet in greatest transverse diameter, and from forty to fifty feet in 
length. Each is made up of materials distinctly stratified in 
planes whose sections are parallel to its longest axis ; this is also 
the direction which the immediately surrounding pebbles have 
assumed. In different patches, however, the inclination varies 
('onsi(loial)ly. Tli<'r(' does not appear to be any marl in the bed, 
