196 CAEBONIFEEOUS VOLCANIC ROCKS OF SOMERSET 
The limestone at the base (No. 1 in the above section) 
contains abundant chert. The basalt (No. 9) is always in 
a very much weathered state, and is sometimes converted 
into a brown, sandy-looking material in which little can be 
made out except the amygdules. The highest bed (No. 14) 
contains larger lapilli than any of the others, as they reach a 
length of 2 inches. They are fairly plentiful up to a 
height of at least 7 feet from the base. 
Second Exposure . — Sir A. Geikie’s and Mr. Strahan’s 
description of this is as follows : — 
“ The next section of the volcanic group has been laid 
bare in a small bay three-quarters of a mile further to the 
east. Here again the rocks have been thrown into a highly 
inclined position, so that a considerable thickness of strata 
has been packed into a narrow strip of the beach. Short 
as is the interval between this outcrop and that just de- 
scribed, the succession of strata between the two places has 
entirely changed. The sheet of lava has disappeared, and 
a number of the tuffs which towards the west are separated 
by layers of limestone here form more continuous deposits. 
But the whole volcanic group is thinner. 
“ At the base of the section the thick crinoidal limestone, 
with bunches of coral in the position of growth, passes 
upwards as before into reddish banded limestone with red 
clay partings, which no doubt represent much-decayed 
fine volcanic dust, for immediately above comes a deposit 
about 50 feet thick of green finely -bedded tuff. This 
band repeats the characters above described. It includes 
in its upper part a coarser layer, which encloses pieces of 
limestone, chert, and basalt, sometimes six inches long. 
It is marked also by the same evidence of contemporary 
organic growth and deposit, for at different platforms 
throughout its mass occur thin layers of ashy limestone 
and dark chert, while some of the finer portions of the tuff 
are nearly as fossiliferous as the ordinary limestone, being 
