Page:The South Staffordshire Coalfield - Joseph Beete Jukes - 1859.djvu/177

Rh during which they twice passed along the same set of beds, rendering it probable that there was an upcast between the downcast faults. Had the dip of the several fragments of beds been given, we might have constructed a very instructive section of this gate-road.

Gornal Wood faults.—Between Gornal wood and the Graveyards there are four faults which strike south-south-west out of the Russell's Hall fault, each having a downthrow of 21 feet to the east-south-east.

It will be seen that not only these, but the other principal faults, namely, the Shut End. Corbyn's Hall, and Brockmoor faults, have likewise a general bearing of north-north-east and south-south-west where their throw is greatest and most decided, and that where they deviate widely from that bearing is where they send out branches that eventually become east and west faults, or where perhaps such faults merge into them,

These east and west faults have generally a less amount of dislocation than the others, the only large throws being in the pair of faults that make the Brierley Hill Trough, and these are only important with respect to the piece of ground which lies between them.

The general effect of the three great north-north-east and south-south-west faults, the Brockmoor, the Corbyn's Hall and the Shut End, is to throw down the measures towards the west, and extend the coalfield in that direction. If it had not been for these breaks it seems likely that the outcrop of the Thick coal south of Brettell-lane might have run in a straight line north-north-east for that north of Turner's Hill by Cotwell End and Sedgley Hall farm.

If the coal had not cropped out along that line, it is at all events very probable that the western boundary fault would have run along it with one great heave of a downthrow to the west bringing in the Permian or New red sandstone beds against the Coal-measures.

Instead of one great heave, we may look upon these three faults as subdivisions of the boundary fault, letting down the coal measures by a succession of steps towards the west before burying them under the other formations.

Between Netherton and Dudley the two basins of Pensnett and Cradley coalesce, the coals and the principal dislocation,—the Russell's Hall fault,—ranging uninterruptedly from one to the other, and the beds dipping north from the end of the anticlinal till they rise to the Russell's Hall fault.

We now come to the part of the coal-field which lies east and north of the main line of division. Before describing the position of the Coal-measures, however, it will be as well to give an account of the Walsall Silurian district and show the connexion between the beds there and those which have been already described as appearing on the Dudley and Sedgley anticlinal.

The Walsall Silurian district is of very irregular shape, owing partly to the action of several faults, partly to the overlapping of the _Coal-measures. In the cutting of the South Staffordshire railway on the west of the town may be seen the calcareous beds of the upper or Little limestone. They dip west at an angle of 5°, and in that direction the Silurian shale becomes shortly covered by the lower Coal-measures containing the Blue flats and other ironstones. On the north of the town, and east of the Lichfield road, are some large old quarries, in which the lower or Thick limestone was formerly worked, dipping westerly at 10°. This limestone must be continued under the town to the southward, being concealed from view by a very thick capping of