GEOLOGY OF SHROPSHIRE. 41 
side of the Lawley, a volcanic hill north-east of Caradoc, and separated 
from it by a gap about a quarter of a mile in width. If the quartzite is 
continuous under the superficial deposits which lie in the gap, the band 
will be over a mile in length. At Caer Caradoc it is about 100 feet in 
thickness, and dips easterly at a high angle. The quartzite is overlaid 
by the Hollybush Sandstone, which is well exposed in its lower part, 
dipping south-easterly at 75°; but towards the north-east end of the hill 
the sandstone shows a tendency to lap round it, and dips to a little 
north of east. A short distance to the south-west higher beds of the series 
dip east-south-east at 35°. The Hollybush Sandstone in places is highly 
quartzose, with grains of green earth and decomposed felspar, and is 
almost undistinguishable from certain parts of the basement beds of the 
Caradoc which appear against the same side of the axis a mile to the 
south-west. This similarity, doubtless, helped to mislead the earlier 
surveyors, and is paralleled by the equally confusing resemblance between 
the Shineton and Harnage Shales, which I pointed out in a previous 
paper.* These sources of difficulty, together with overlaps, inversions, 
and numerous and heavy faults, render the district a perfect maze of 
perplexity. Happily, the identity of the sandstones is clearly established 
by an excellent section exposed in a quarry at the north-east end of 
Little Caradoc. 
In the middle of this section is a thin band which deserves special 
attention. It is less than one foot in thickness, and is a dark-coloured 
compact limestone. Associated with it is a little red shale, and near the 
surface of the bed the limestone assumes the same colour. This band is 
very fossiliferous, the most abundant form being apparently trilobitic; 
but it occurs in such a fragmentary condition, and is of such an unusual 
type, that I cannot express any opinion on its generic affinities. 
Brachiopoda are not uncommon: two or three species are undetermin- 
able, save that they belong to the Tretenterata. One form, a minute 
roundish Lingulid, is apparently new. Whatis of more importance for 
our purpose is that the bed contains two well-known Malvern species, 
Kutorgina cingulata, Bill., and Serpulites fistula, Holl., both of which are 
found inthe same formation on the flanks of the Wrekin. The Holly- 
bush Sandstone is thus shown to overlie the quartz rock, as in the 
Wrekin district. It is about 300 or 400 feet in thickness, and extends to 
the south-west for some distance ; but I have not traced it quite so far as: 
the quartzite. Indeed, the exact limits of both formations are not ascer- 
tained, the exposures towards the south-west being very few and slight. 
I have had the good fortune to discover the presence of the Shineton 
Shales in their true place above the Hollybush Sandstone of this sub-area. 
They are seen in the road leading up from the gap towards Shoots Rough. 
The width exposed represents a thickness of about 30 feet, and the dip 
is east or east-south-east apparently at 35°. They are succeeded by the 
Hoar Edge Grits, (Lower Caradoc,) which plunge towards them at an 
angle of 60° or 70°. In the Shineton district the shales are apparently 
conformable to the over-lying Caradoc, and the chief evidence for the 
* Midland Naturalist, Vol. I., p. 206. 
