Geological evidence for continental drift

The geological record contains evidence for the location and arrangement of continents way further back in time than fossils or glacial deposits. Cores of continents are made up of cratons, some of the oldest rocks found on Earth. Some cratons are more than 4 billion years old. Occurrences of cratons match across different continents on both sides of the Atlantic Ocean, such as in South America and Africa.

Apart from this geological fit, Alfred Wegener also discovered a tectonic fit. He noticed that several mountain ranges on both sides of the North Atlantic Ocean formed around the same time. The Appalachian Mountains in the US and the Scottish Highlands in Europe have around the same formation age. Wegener concluded that they formed during one mountain-building event around 400 to 480 million years ago. When continents are re-assembled without today’s North-Atlantic ocean in between, those mountain ranges actually align in one huge mountain belt.

Figure 1: Distribution of cratons (Southern Hemisphere) and mountain ranges (Northern Hemisphere) serves as geological evidence for the continental drift theory.