What was Alfred Wegener's theory of continental drift? What evidence did he have to support his theory? Why was his theory originally rejected?

Answer 1

· Alfred Wegener's theory of continental drift was proposed in 1912. This theory maintained that all the continents were once connected into a single continent. Wegener called this large continent Pangaea and the surrounding ocean Panthalassa. He thought that Pangaea began to break into continents about 200 million years ago.
· Wegener used the shape of the continents from the north and south Atlantic to show how the continents would have fit together. There was also an alignment of mountain ranges of similar age, composition, and structure on different continents.
· Sir Ernest Shackleton discovered coal in Antarctica which meant that at some point there were tropical plants where it is now freezing. This added to Wegener's evidence of continental drift.
· There were similar fossils found on different continents.
· Wegener proposed that the continents moved due to a combination of the centrifugal effect of being slung towards the equator and tidal drag. Wegner lost credibility among scientists by selecting only the data that would support his theory and ignoring contrary data. There were holes in his theory, including a lack of evidence on the floor of the ocean that continents had moved.