South of Dudley this anticlinal form of the beds ceases, but the line of division is continued partly by the surface feature of the Basaltic hills and a steep western slope that runs from them to the south, but chiefly by a line of fault below the surface, having a great downthrow to the west-south-west, which we may distinguish as the Russell's Hall fault. To the south of the Basaltic range this line of fault appears as if again about to take an anticlinal form, since the Coal-measures rise sharply up to it from the west-south-west, if not from both sides. The line of division is then lost for a space, but re-appears again in almost exactly the same line of bearing in the narrow and broken anticlinal ridge of the Lower Lickey Hills (Rubury Hill and the Bilberry Hills).
We may speak of the part of the coal-field lying west of the line above indicated as the South-Western portion of the coal-field. It is subdivided into two by the Netherton anticlinal, a line 3 miles long running north-north-east and south-south-west, with the Silurian showing itself in its southern portion, and the coals cropping out on both its flanks and round both terminations.
The basin between the Netherton anticlinal and the Russell's Hall fault we may call the Cradley Basin. This basin seems to be comparatively free from faults, and except those that bound it has certainly no dislocations of great magnitude. .
The basin lying between the Netherton anticlinal. Kingswinford, and Gornal we may call the Pensnett basin. This is traversed by a number of large and important faults that will be described more in detail presently.
Where the Netherton anticlinal ceases towards the north, there is a trough or hollow in the beds, nearly a mile wide, between it, and Dudley, forming a channel connecting the Cradley and Pensnett basins. We will speak of this as the Old Buffery Trough, from the name of some ironworks situated in it.
The other principal part of the coal-field lies to the east and north of the main line of division before described. It is subdivided into two by the Great Bentley fault, which a little north of the latitude of Walsall rune across the coal-field from east to west, with a downcast of 360 feet (120 yards) to the north.
South of the Great Bentley fault lies the central and south-eastern part of the coal-field. The central is the part between the Dudley and Sedgley anticlinal and the Walsall Silurian district, both on the east and west side of which the Coal-measures successively crop out, and allow the Silurian rocks to appear from underneath them. They also mse, but much more gently, towards the north, the Thick coal. Heathen coal, and New Mine coal cropping out one after another in that direction, and the beds below them being at a very slight depth when they range up to the Great Bentley fault. This central district is traversed by many east and west faults, all having their greatest throw in the middle of their range, and all being downcasts to the south till we
