Continental Drift and Pangea Overview

Alfred Wegener's hypothesis that Earth's continents were once joined in a single landmass called Pangea, which broke apart around 200 million years ago, sending the continents adrift.

Similar fossils of animals and plants found on widely separated continents, suggesting they once lived in a connected landmass.

Matching rock formations, like those found in the Appalachian Mountains of North America and similar mountains in Greenland and Europe, support the idea of once joined landmasses.

Evidence of past glacial activity on continents now located in warm regions, like Antarctica, suggests they were once situated closer to Earth's poles.

A device used to detect small changes in magnetic fields, helping map the ocean floor and discover ocean ridges.

Vast underwater mountain chains that run along the ocean floor around Earth, formed by tectonic plate movement.

Deep trenches found alongside ocean ridges, formed when one tectonic plate slides beneath another.

Samples of sediments and the underlying oceanic crust collected from the deep sea, offering insights into the history and composition of the ocean floor.

The process where new ocean floor is created at ocean ridges and then moves away from the ridge, eventually being destroyed at trenches.

The oldest parts of the seafloor are found further away from the mid-ocean ridge because they are the oldest.

The amount of sediment on the ocean floor increases with distance from the mid-ocean ridge because older areas have had more time to accumulate sediment.

The theory of seafloor spreading explains how new ocean floor is formed at ocean ridges and then moves away.

Oceanic crust is thinner than continental (land) crust.