| Answer | Crossword Clue |
|---|---|
| chine | ravine formed in rock by the action of running water |
| chines | ravine formed in rock by the action of running water |
| tomo | a shaft formed by the action of water on limestone or volcanic rock |
| potholes | A deep natural underground cavity formed by the erosion of rock, esp. by the action of water |
| coulee | deep ravine or gulch, usually dry, that has been formed by running water |
| coulees | deep ravine or gulch, usually dry, that has been formed by running water |
