| Rating | Solver | Clue |
|---|---|---|
| CORAL | Marine formation | |
| FORMATION | Mineral deposits and rock masses designated with reference to their origin; as, the siliceous formation about geysers; alluvial formations; marine formations. | |
| SUBCARBONIFEROUS | Of or pertaining to the lowest division of the Carboniferous formations underlying the proper coal measures. It was a marine formation characterized in general by beds of limestone. |