758 



C* CALLAWAY ON THE QfTARTZTIES OF SHROPSHIRE. 



sits 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. At this part of the range a notch separates the main mass 

 of the hill from its north-eastern prolongation, a mneh lower eleva- 

 tion, called Little Caradoc ; and the quartzite is well seen the entire 

 length of the south-eastern flank of the smaller hill, extends into the 

 notch and partially overhangs its north-west side, and is seen for a 

 short distance along the south-east side of the main mass. It can 

 hardly extend much further to the south-west, since the Caradoc 

 Sandstone soon appears in force, and is for many miles the lowest 

 formation exposed on this side of the axis. 



The quartzite is overlain 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 ten- 

 dency to lap round it, and dips to a little north of east. A short 

 distance to the sonth-west higher beds of the series dip east- south- 

 east at 35°. The Hollybush in places is highly quartzose, with 

 grains of green earth and decomposed felspar, and is almost undis- 

 tinguishable 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 sur- 

 veyors, and is paralleled by the equally confusing resemblance be- 

 tween 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 per- 

 fect maze of perplexity. Happily, the identity of the sandstones is 

 clearly established by the following section," which is exposed in a 

 quarry at the north-east end of Little Caradoc. 



Fig. 3. 



Section of Hollybush Sandstone at the north-east end of 

 Little Caradoc. 



T$. 80° E. 



S. 80° W. 



The beds a are ordinary Hollybush Sandstone, consisting of 

 rounded grains of a felspathic mineral and of green earth, with a little 

 mica. At b the rock is more quartzose, and decomposition is more 

 advanced. The underlying beds (c) are conglomeratic, the pebbles 



Quart, Journ. Geol. S'oe. rol. xxxiii. p. 653, 



