Answer:
Different rock types and mountain belts on opposite sides of the Atlantic.
Explanation:
The plate tectonics theory is a theory that suggests that Earth's crust is divided into numerous pieces that are constantly moving, driven by the force of the convection currents from the mantle below them. It is a theory that has been put in the spotlight by Wegener, and gradually, with more and more evidence being put on the table, it became a widely accepted theory.
The evidence consists of fossils, sea-floor spreading, hot spot island arcs, matching continental margins, the same type of rocks from the same age in different continents, etc. The latter is evidence that tells us that mountains, now on different continents, were actually part of a single mountain range, but over time were separated. Such is the example with the Appalachians on one side, and the mountains of Greenland, Ireland, Britain, and Norway, all having the same rocks with the same composition, formed at the same time.
