Across
- 2. a deep undersea valley where crust sinks toward the mantle
- 4. ocean ridge an under sea chain of mountains that is part of a long system of underwater mountains
- 5. good for growing crops
- 7. the process by which crust sinks back into the mantle at a colliding plate bountrie
- 9. floor spreading the proses by which molten material adds new crust belo earths bodies of water
Down
- 1. a tool used to spread water across fields
- 3. a waterfall
- 6. a devise that reflecks sound waves off underwater objects and records the echoes
- 8. the area near a river's mouth where the water deposits fine soil