the name of some old ironworks therein, the Buffery trough. It is just here also, where the two anticlinals of Netherton and Dudley terminate, that there is the closest connexion between the south-west and the central portion of the coal-field. The Thick coal and other beds dip towards the Buffery trough, not only from Netherton, but also all along the south side of Dudley, whence it gradually curves round so as to dip first towards the Rowley Hills and then towards Tipton. The only thing, in fact, which separates the two districts here is the Russell's Hall fault, which is here a simple fracture and downthrow of about 150 feet towards the Buffery. If it were not for this dislocation the central and south-western districts would here become confluent, just as the Cradley and Pensnett basins become confluent.
Now it is from this neighbourhood that the most powerful and dominant fracture strikes into the central district, nearly parallel and almost in a line with the axis of the Netherton anticlinal. This fracture consists of the pair of faults which produce the Dudley Port trough.
At the time when the coal-field was first surveyed these faults were supposed to cease altogether on approaching the basalt of Cawney Hill. In the partial revision of the district, however, which I was able to make in October 1858, there appeared good reason for believing that they did not entirely cease, but that the basalt cf Cawney Hill was cut off on the north by the continuation of the north-western fault, and that it was partly separated from that of Tansy Hill by the opposite fault. It is probable, then, that the Dudley Port Trough faults do not entirely cease till they strike the Russell's Hall fault a little to the north-west of Gad's Green reservoir.
Now, it is very remarkable that a small fault proceeds from the northern apex cf the Netherton anticlinal obliquely towards the same part of the Russell's Hall fault. There seems, then, to be almost a direct connexion between the Netherton anticlinal and the Dudley Port trough.
If we produce the axis of the Netherton anticlinal it will strike exactly into the centre of the Castle Hill dome-shaped elevation.
I believe we have in these and similar facts a proof that the forces of elevation and disturbance which were acting on the country to produce the principal features in the lie of the rocks acted along lines running north-north-east and north-north-west, here one force and there another predominating, and producing N.N.E. or N.N.W. fractures or elevations accordingly, with occasional oblique connexions between two parallel and adjacent lines of effect. The two forces seem also to have been sometimes so equally balanced as to have their direction resolved into lines equidistant between them, and therefore running either north or south, as in the Castle Hill and the Wren's Nest, or cast and west, as in some of the large faults and dislocations. The north and south lines of course bisected their smaller angle of intersection, the east and west lines the larger angle.
Having dwelt long enough, perhaps, on what is believed to be the law governing the direction of these lines of disturbance. I will now proceed to describe those of the central district a little more in detail.
The Dudley Port Trough faults.—These are two parallel faults starting from near the Free bodies at the north-west corner of the Rowley Hills, and running about north-north-east for about 2 miles up to the Horsley collieries. They are scarcely a quarter of a mile asunder, and each throws down the piece of ground between them to the maximum depth of 130 yards; that is, the piece of Thick coal between them is 130 yards (or 390 feet) deeper than that on either side. (See Fig. 24.)
