Across
- 2. a section of the Earth’s crust and upper mantle that floats on the soft, hot rock of the mantle
- 3. a very deep, wide valley that forms on the ocean floor at a subduction zone
- 5. a break in the Earth’s crust
Down
- 1. the slow up-and-down movement of the hot, soft rock within the Earth’s mantle
- 4. a deep valley that forms when plates move away from each other