529 
At N. end of Tunnel solid beds come in, succeeded by reddish 
beds, and capped with horizontal beds of Dolomitic Conglomer- 
ate. A large quarry is being worked on the E. side of the 
line, the beds of which are fossiliferous and Oolitic, containing 
Producti, Spirifers, Univalves (Loxonema?,) and encrinital joints. 
The estimated depth of the quarry from 18 to 20 ft., beds dipping 
about 20°S.E. by E. Some microscopical sections were taken 
from the Oolitic beds on the W. side (the last series of solid 
beds coming in before the shales.) These beds may possibly be 
paralleled with those at Clifton gully quarry. Horizontal 
distance from N. end of Tunnel to last of Oolitic beds as 
measured by scale on Section, about 1667 ft. Taking the dip 
at 20°, this would give total thickness as ... 
The Oolitic beds are about 19 ft. thick apy s 
The fissile limestone beds on N. side and just fitiee ividpe 
No. 16, are very fossiliferous, containing abundance of Encri- 
nital stems, Spirifers, Chonetes, Athyris, &c., and Fenestella tuber- 
culata-arenata. Ossicles of Pentacrinite also occur sparingly. 
They may be estimated as 85 ft. thick 
The passage from Middle limestones to ewes lievextans shale 
seems to be opposite shed on right hand of line, 85 ft. below 
Oolitic beds ; and the black shales were seen at N.W. corner of 
bridge. From this point to the first appearance of the “‘Bryozoa” 
beds on the N. side, the thickness may be estimated at from 
85 to 90 ft. ae se oe oe ace se 
From the incoming of the “ Bebeoe! bed through a succession of 
Old Red Marls and Sandstones, green, grey, and red, to the first 
fine grained Conglomerate, with milk white quartz pebbles at 
From the latter beds to the coarser grained Old Red Conglomerate 
at the mouth of Groves End Tunnel at : 
This Conglomerate dips at an angle of 16° S.E. anal nesiaeas 
pebbles of white and pinkish vein quartz, mottled green pebbles, 
Silurian quartzite, or Lydian stone. About 28 ft. of this is 
exposed ; then Groves End Tunnel conceals the beds for a 
space of 492 ft., they then appear again on the other side, 
and continue to the end of the cutting, being unconformably 
overlaid by coarse beds of Dolomitic Conglomerate, these being 
succeeded by the finer grained Yellow Limestone and clays 
which die out just beyond the little wooden foot bridge which 
crosses the line near the 63 mile post. 
It may be mentioned here that Sir Roderick Murchison remarks 
on the peculiarity of structure which the Old Red of the 
Tortworth district presents. The upper beds, instead of being 
fi. im: 
. 527 
19 
85 
90 
126 
. 215 
