Wegener's Bold Hypothesis
In 1912, Alfred Wegener noticed that the coastlines of Africa and South America fit together like puzzle pieces. He proposed that all continents were once joined in a supercontinent he called 'Pangaea' and had since drifted apart. His evidence — matching fossils, glacial deposits, and geological structures across oceans — was compelling, but he could not explain the mechanism. It took 50 years and the discovery of seafloor spreading to vindicate his vision.
Pangaea and the Supercontinent Cycle
Pangaea assembled between 335 and 250 Ma as the ancient continents of Gondwana and Laurasia collided, closing the Rheic and Iapetus oceans. By 200 Ma, rifting began — first separating North America from Africa to open the central Atlantic, then fragmenting Gondwana to create the Indian, South Atlantic, and Southern oceans. Earth has experienced multiple supercontinent cycles: Rodinia (~1 Ga), Columbia (~1.8 Ga), and potentially Kenorland (~2.5 Ga).
Evidence from Multiple Disciplines
Continental drift is confirmed by converging evidence: paleomagnetism records the latitude of rocks when they formed, showing continents have migrated thousands of kilometers. Identical Permian glacial deposits span South America, Africa, India, and Australia — separated by oceans today but contiguous in Pangaea. The Mesosaurus, a freshwater reptile, is found only in Brazil and South Africa, implying a land connection. Matching mountain belts, like the Appalachians and Caledonides, were once a single chain.
The Future: Pangaea Proxima
Plate tectonics continues. The Atlantic is widening, the Pacific is shrinking, Africa is colliding with Europe (raising the Alps), and Australia is drifting north toward Southeast Asia. In ~250 million years, models predict the continents will reassemble into a new supercontinent — variously called Pangaea Proxima, Amasia, or Novopangaea — continuing the grand cycle of assembly and dispersal that has shaped Earth for billions of years.