Across
- 6. The process by which crust sinks back into the mantle at a colliding plate boundary.
- 7. A mixture of copper and tin used to make stronger tools
- 8. spreading The process by which molten material adds new crust below earth's bodies of water.
- 9. A person who specializes in writing and services as a record keeper.
Down
- 1. A deep undersea valley where crust sinks towards the mantle.
- 2. A device that reflects sound waves off underwater objects and records the echoes.
- 3. A picture or drawing that represents a word or idea
- 4. A sharpened reed used to press markings into clay tablets.
- 5. ridge A undersea chain of mountains that is part of a long system of underwater mountains.
- 8. A sharpened reed used to press markings into clay tablets