and mottled clays and marls, with interstratified sandstone bands, that dip apparently east-south-east at 40°. Over these in a field opposite the Gough's Arms is a band of the calcareous conglomerate, just the same as that of Barnford Hill before described, dipping cast-south-east at 20°. These are all evidently Permian beds. On the higher ground, where "Quarry" and "Snail's Green" is engraved in the Ordnance map, we find a large gravel-pit opened in the quartzose conglomerates forming the base of the New red sandstone.
Further north we get red sandstone and marl, probably Permian, on a level with the Barr limestone near "the Skip," and following on to the east of Hay Head we find red rocks to the east of a certain curved line, while there are Silurian and Coal-measures on the west of it. The way in which the two little bits of Llandovery sandstone are allowed to peep out at Shustoke Lodge and behind Daffodilly, while over the intermediate space the Wenlock shale appears to come directly against the red rock, may be explained on the supposition that the fault here is a waved and gently indented line, and that as the Silurian beds crop towards the east, when the fault makes an eastward bend, it allows the lower rock to crop out, while when it bends to the west it cuts into higher beds, and of course prevents the outcrop of the lower.
So far I have endeavoured simply to describe facts, and give their most obvious explanation. Still it cannot be denied that there is something yet to be learnt respecting the nature of the boundary of the coal-field between Hay Head and Lappal. We may readily allow the boundary between the red rocks (taking Permian and New red sandstone together) on the one side, and the Silurian and Coal-measures on the other, to be an ordinary fault with a large downthrow to the east all the way from Hay Head south to Sunday Bridge. But we are then driven to the supposition that it splits, and that of the two branches into which it divides, one soon ends in the red rocks, and the other goes on at right angles to the former course[1] until it meets another fault running parallel to the first, and likewise forming a boundary between the red rocks and the Coal-measures. Now there is, in fact, little or no evidence for this splitting of the boundary fault, and we cannot at all satisfactorily account for the southern termination of the part of it that runs by Barr.
Again, the fault running by Oldbury is certainly a large downthrow to the east, and it certainly forms the boundary line between the red rocks and the Coal-measures at the surface, but it can hardly be called the boundary of the coal-field, inasmuch as the coals are got for a mile or more to the east of it, at only a comparatively slight increase of depth. Not only so, but the Coal-measures appear even at the surface on the eastern side of this fault, both north of the red rocks towards West Bromwich, and southwards towards Wilderness Farm and the Stone House. That this appearance of Coal-measures is due to cross faults cutting off the red rocks in each direction is at present a mere arbitrary and gratuitous supposition, though it is perhaps the most probable explanation of the facts that can at present be given.
Mr. Hull examined and determined the boundaries of the New red sandstone from Hampstead Hill through Smethwick and Harborne, and
- ↑ It might give a more natural aspect to the facts, perhaps, if we supposed another branch to spring from the boundary fault between Ray Hall and Small's farm, and run a little north of West Bromwich old church to the fault that cuts off the Thick coal crop of the Hall End colliery. This line of fault would blend with that which certainly runs under the Cross Guns more easily than the one engraved on the nap south of Church Vale, or, perhaps, the two together might form steps letting down the Thick coal under Virgin's End, &c.
