Alfred Wegener
Topic: Continental Drift, Sea-floor Spreading and Plate Tectonics · NCERT: Class 11, Ch 4 "Distribution of Oceans and Continents"
Meaning
Alfred Wegener (1880-1930) was a German meteorologist, someone who studies weather. In 1912 he put forward the continental drift theory. It says that all continents were once one landmass, called Pangaea, which broke up. The pieces then slowly drifted to where they are now. He backed the idea with matching coastlines, matching rocks, tillite (rock left behind by glaciers) and matching fossils. Most scholars rejected the forces he gave for this movement, the pole-fleeing force and the tidal force, because they were far too weak. Decades later, ocean-floor studies and plate tectonics (1967) brought his core idea back. He set out the theory in The Origin of Continents and Oceans (1915). He died on a Greenland expedition in 1930.
Example
Wegener used the Gondwana system of central India as evidence. It has thick tillite at its base, and the same rock sequence appears in Africa, Madagascar, Antarctica and Australia. This showed that these lands once lay together under one ice sheet.
Don't confuse with
- Arthur Holmes: In the 1930s Holmes suggested that convection currents in the mantle move the continents. He was supplying the force that Wegener could not explain.
- Harry Hess: Hess proposed sea-floor spreading in 1961. His theory explains how ocean floors widen, while Wegener's evidence came mostly from the continents.