north at about 45°. Along the east and south-east sides of the hill, however, the inclination of the beds is much steeper, rising to 50°, 60°, and in one part upwards of 80°. At the south-east corner the beds, instead of bending regularly round, are broken through by a fault, so that the end of the upper limestone on the west of the fault is made to abut against the base of the lower limestone on the east side of it. The lower limestone of the east side is itself cut off by the fault a little farther south, but the upper limestone ranges some distance to the south alongside of the fault till, being finally traversed by it at a very oblique angle, it also disappears. The course of the fault towards the north may be traced a little way by the ending of the lower limestone on its west side, but it very likely runs up to the centre of the hill. From this spot a fault runs due east, cutting through the beds on that side of the hill, and shifting their outcrop 30 yards, so that the upper limestone on the south side of it is made very nearly to face the lower limestone on the north; from which it follows that this must be a very considerable downcast to the south, the beds north of it rising at an angle of 55°, those to the south at one of 80°.
Fig. 19.
Caverns, West Side of Wren's Nest.
About 250 yards north of this another east and west fault cuts right across the ridge, fracturing the beds on the east side, and entirely cutting off those on the west.[1] From the centre of the ridge where it is traversed by this fault another is supposed to spring, running north-west, in order to account for the sudden ending of the two limestones in that direction as they curve round from the north-east side of the hill.
- ↑ It is worthy of remark that these faults in the Wren's Nest and the other Silurian elevations do not appear to affect the Coal-measures, although it is clear that these dome-shaped elevations did not take place till after the Coal-measures were deposited. It is plain, therefore, that the cracks and fissures of the dome-shaped elevations are strictly local, or have not much longitudinal extension.
