Across
- 2. a sharpened reed used to make markings into clay tablets
- 4. a person who specializes in writing and serves as a record keeper
- 5. a type of writing made up of wedge-shaped markings
- 6. a deep undersea valley were crust sinks toward the mantle
- 8. a picture of drawing that represents a word or idea
Down
- 1. a mixture of copper and tin; that is used to make stronger tools
- 2. spreading the process by which molten material adds new crust below earths body's of water
- 3. a device that reflects sound waves off underwater objects and records the echoes
- 4. the process by which crust sinks back into the mantle at colliding plate boundary
- 7. ocean ridge an undersea chain of mountains that is part of a long system of underwater mountains