| Rating | Solver | Clue |
|---|---|---|
| OZONE | Earth's protective layer | |
| SUBSOIL | Earth layer | |
| TOPSOIL | Uppermost earth layer | |
| SOIL | Top layer of earth | |
| CRUST | Outermost layer of the earth | |
| MANTLE | Middle layer in the earth's internal structure | |
| SLOAM | A layer of earth between coal seams. | |