CAKBONIFEEOUS VOLCANIC ROCKS OP SOMERSET 203 
the Geological Society, to reprint, contains a far fuller 
account of the lava than has hitherto been published, and 
presents many new observations. He begins with a general 
description of the rocks : ^ — 
“ The basalt at Spring Cove, immediately north of 
Weston Pier, runs obliquely to the high road, and is 
exposed from low-water mark along the foreshore into 
the face of the cliff, the exposed length being about 150 
yards. The massive beds of Carboniferous Limestone, 
between which the basalt is intercalated, strike north- 
eastward, and dip south-eastward (towards Weston) at 
about 40°. The basalt sheet is parallel to the bedding of 
the limestone, and has a thickness of about 45 feet. 
“ A traverse from end to end of the exposure shows 
clearly that the rock varies considerably in structure and 
appearance, and that it is by no means a simple basalt- 
lava flow. Starting from low-water mark, the rock is a 
hard, compact, red, slightly amygdaloidal olivine-basalt, 
containing very occasional lumps of limestone, from a few 
inches to a foot or more across. For the first hundred 
yards its upper junction with the limestone cannot be 
seen, because of the accumulated boulders at the foot of 
the cliff, while the lower junction is covered with water, 
even at lowest spring- tide. Then, a little more than half- 
way from the low-water end, and along to the cliff, the 
basalt changes in character somewhat suddenly. It now 
contains big lumps of burnt limestone, and the whole mass 
becomes broken up into a very coarse tuff or agglomerate, 
containing great lenticular masses of highly slaggy basalt, 
5 to 6 feet long, together with lumps and bands of lime- 
stone, often considerably fractured, and up to 10 or 12 feet 
in length. About 20 or 30 yards further on, and as far as 
the end of the exposure in the cliff, the rock is more uniform 
in character, being a ‘ pillowy ’ basalt, though considerably 
1 Quart. Journ. Qeol. Soc. vol. lx. p. 158. 
