In some parts around Dudley the ironstone of these measures is called "Blackstone," to distinguish it from the "Whitestone," hereafter to be described.
About Bentley this Gubbin ironstone has a little coal associated with it, as in the following section:—
| FT. | IN. | |
| Binds | 1 | 0 |
| Ironstone (Gubbin) | 0 | 6 |
| Binds and batt | 1 | 3 |
| Coal and batt | 1 | 2 |
| Fire-clay | 0 | 10 |
| Coal | 0 | 7 |
| Binds | 21 | 0 |
| Clunch and ironstone | 3 | 0 |
| Black batt | 0 | 11 |
| 29 | 3 |
Comparing this section with the one given below from Claycross, it seems probable that the Black batt 11 inches which rests directly on the Heathen coal, is in reality the Table batt, which at Claycross also reposes directly on the Heathen coal.
15. Table batt and intermediate measures.—The Table batt is a very compact, black, carbonaceous shale, splitting into large slabs, which when first exposed look firm, but soon crumble to pieces. It is found throughout the southern district with a thickness varying from 2 to 4 feet, except in the neighbourhood of Congreaves, and thence towards Stourbridge and Kingswinford, where I find no mention made of it, and around Corbyns Hall it is only 1 foot thick. Sometimes it has associated with it a little coal and ironstone, as in the section at Claycross, near Dudley, which will be useful for comparison with sections farther north:—
| FT. | IN. | |
| Sharp batt | 1 | 6 |
| Rubble stone | 0 | 5 |
| Little coal | 0 | 6 |
| Brown stone | 0 | 5 |
| Table batt | 2 | 6 |
| 5 | 4 |
The measures between the Table batt and the Heathen coal are wholly confined to the district between Walsall and Wolverhampton. We have seen that in the south-western angle of the coal-field the last measure is wanting, and there the Gubbin ironstone measures rest directly on the Heathen coal. Proceeding in every direction from this part, the Table batt comes in between them, at first only a few inches thick, but gradually swelling to 4 feet. Still, in the district around Dudley there is nothing else to be found between the Gubbin and the Heathen coal; hut, as we approach Bradley, we get eventually about 10 feet of fire-clay and clunch, and farther north we find a pretty regular thickness of, from 18 to 24 feet (or 6 to 8 yards) of clunch, binds, or other argillaceous material, commonly of a white colour, interposed between the black table batt and the heathen coal. Sometimes a "black ring,"[1] or a small coal 6 or 8 inches thick, makes its appearance
- ↑ A "black ring" when mentioned in a pit section means an impure coaly bed, sometimes called "smut," &c.; it forms a black ring round the shaft, whence its name.
