| Answer | Crossword Clue |
|---|---|
| SEAM | Coal bed |
| SEAM | Coal bed. |
| SEAM | Bed of coal |
| SEAM | Bed of coal. |
| SEAM | Bed of coal or other valuable mineral. |
| seam | bed of valuable mineral and especially coal irrespective of thickness |
| seams | bed of valuable mineral and especially coal irrespective of thickness |
| underclay | a stratum of clay lying beneath a coal bed, often containing the roots of coal plants |
| underclays | UNDERCLAY, a stratum of clay lying beneath a coal bed, often containing the roots of coal plants |
