Across
- 3. ------ spreading is a geologic process in which tectonic plates split apart from each other.
- 4. A supercontinent made up of all the continents that existed millions of years ago.
- 5. Harry ---- discovered seafloor spreading.
Down
- 1. Plate ------- is a scientific theory that considers the Earth's lithosphere to comprise a number of large plates that have been moving for millions of years.
- 2. Alfred ------ theorized that the continents were originally were one supercontinent and moved.