646 C. CALLAWAY ON THE PRECAMBRIAN 
Fig. 1.—Section across N.E. end of Lilleshall Hill. 
a, c, e. Hornstone. 6, d. Ash. 
In a series of rocks from Charnwood Forest I have observed a 
slate which suggests, though it is quite distinguishable from, the 
grey slate S.W. of the large quarry. Prof. Bonney has also 
noticed this resemblance. 
On the N.W. side of Lilleshall Hill are faulted beds of Bunter 
Sandstone; and on the 8.E. the Hollybush Sandstone is thrown 
down. On the N.E. the axis of the ridge is prolonged under the 
Carboniferous Limestone, which is bent into an arch by the subse- 
quent elevation of the Precambrian axis. To the S.W., a 8.W. line 
of fault, Bunter Sandstone against Coal-measures, connects Lille- 
shall Hill with the Wrekin, and the axis is undoubtedly continued 
under the younger formations. 
Summary.—A §.8.W. ridge, composed of alternations of horn- 
stone and ashy slates and shales, with felspathic agglomerates in 
the middle. Average dip of 40° to N.N.W. Minimum thickness 
1500 feet. Bounded by two nearly parallel faults, converging at 
each end, Bunter Sandstone being thrown down on the N.W., 
Hollybush Sandstone on the 8.E. 
2. The Ereal (figs. 4 & 5, p. 650). 
Details —On the N.W. slope of this hill, just overlooking the town 
of Wellington, is a large quarry, distinguishable for miles by the 
colour of the bright red felspathic rock of which the exposure 
chiefly consists. Near the surface this rock is divided by very close 
joints, and it is easily shovelled away as gravel. It forms a broad 
zone, striking EK. and W. across the face of the quarry. It is under- 
lain by a grey or greenish-white rock, forming a zone parallel to 
the upper red band for the entire breadth of the section. The dip 
of the red rock is apparently to the S., that is, opposite to the pre- 
valent dip of the Wrekin chain. Following this rock from the N.E. 
end of the Ercal, just above the quarry, along the ridge to the 8.W., 
we come in about half a mile toa sudden change. The red rock 
abruptly gives place to a compact felstone, dipping N.N.W. at 50°, 
which is exposed in a buttress which supports the ridge on the 
N.W., and still more conspicuously in the broken crags at the 8. W. 
end of the hill. 
It might, at first sight, seem as if the Ercal were composed 
of beds lying in a synclinal; but the great difference between the 
rocks at the opposite ends appears to negative this supposition. I 
