654 (. CALLAWAY ON THE PRECAMBRIAN 
p- 667) striking across the centre of the hill from E. to W., and 
dipping to the N., that is, with the ncermal dip and strike of the 
Salop Precambrian rocks. The contained pebbles are well rounded; 
they consist of quartzite, quartz, gneiss, mica-schist, red felspar, 
and granitoid rock. This assemblage strongly suggests derivation 
from the Malvernian series represented at Primrose Hill*. The 
matrix is apparently ash. This bed is indisputably a subaqueous 
formation; it appears to be on the same horizon as the tuffs of 
the Wrekin. Following this conglomerate along the strike to the 
K., it is seen to end abruptly against a reddish felspathic rock, pro- 
bably intrusive. 
Below the conglomerate, and occupying the south end of the hill, is 
a rock which [ have cbserved in no other Shropshire locality. Itisa 
mass of porphyritic felstone, composed of crystals of red and green 
felspar in a dark green matrix. The hill at this point is flanked by 
quartzite. 
There is a fine exposure of Precambrian rock in the road 8.E. 
of Charlton Hill. In the upper part is a compact red felstone; 
below this are beds of greenish claystone, with gritty bands, made 
up of small rounded fragments similar to the pebbles of the chief 
conglomerate, the prevailing constituents being quartz and a red 
felspar. These seams of grit have all the appearance of derivation 
from the same land as the conglomerate, but from a greater dis- 
tance, the pebbles being much smaller and being more exclusively 
composed of the less destructible rocks. A little lower down the 
road is an instructive junction of the older Precambrian beds with 
the overlying quartzite, which dips §.8.E. at 60°. 
In a small boss to the 8. of Charlton Hill is an indurated tuff of 
the ordinary Wrekin type, associated with gritty beds. Quartzite 
dips away to the south. ; 
Summary.—Conglomerates, grits, claystones, and tuffs, with a 
general dip to the N.; felstone, sometimes porphyritic; quartzites 
dipping away from bosses of the older series in all directions. 
8. District between the Wrekin and the Lawley. 
The two areas are connected by a south-west line of fault. On 
this line igneous rocks are exposed at two points. The first is in a 
cutting on the Severn Valley Railway, near Cound Cottage, about a 
mile south-west of Dryton Bank. The rock is a dark brownish- 
green fine-grained dolerite, with amygdaloids of calcite. The other 
spot is a mile and a half further to the south-west, where a small 
quarry has been opened, on the opposite side of the ravine from the 
great sandstone-quarry of Cound Moor. Here also the rock is a 
greenstone; but it is more coarsely crystallized, the felspar and the 
augite (or hornblende) being readily distinguishable. Higher up on 
* Tn this conglomerate I have made out eighteen varieties, more than half 
of which I haye recently recognized in Anglesey.—C. C., Sept. 1879. 
