Although he did not present a mechanism, what were the key points of Alfred Wegener’s proposal for the concept of continental drift?

Alfred Wegener, a German meteorologist, proposed the theory of continental drift in 1912. Here are the key points of his proposal:

1. Fit of the Continents: Wegener noticed that the coastlines of some continents, like South America and Africa, seemed to fit together like a jigsaw puzzle. This led him to propose that these continents were once joined together and have since drifted apart.

2. Fossil Evidence: Wegener pointed out that identical fossils were found on continents that are now separated by vast oceans. He argued that this could be explained if the continents were once connected, allowing these organisms to inhabit a large, continuous landmass.

3. Rock Formations and Mountain Ranges: Wegener also noted that similar rock formations and mountain ranges could be found on continents that are now far apart. He suggested that these similarities could be explained if the continents were once joined together.

4. Climate Evidence: Wegener found evidence of past climates in locations where they would be unexpected if the continents were always in their current positions. For example, he found evidence of glaciation in present-day tropical regions, suggesting that these areas were once located near the poles.

5. Paleomagnetism: Although this was not part of Wegener's original proposal, later research into the magnetic properties of rocks provided further support for the idea of continental drift.

Despite these compelling arguments, Wegener's theory was not widely accepted during his lifetime. This was largely because he could not provide a satisfactory explanation for the mechanism that would cause the continents to move. It was not until the development of the theory of plate tectonics in the 1960s that a mechanism for continental drift was finally identified.