Pangaea and Continental Drift

Subject classification: this is a history resource.

Continental Drift

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Picture of Alfred Wegener
  • Idea was first proposed by Alfred Lothar Wegener (1 November 1880 – November 1930), a German scientist, whose idea of Continental Drift was controversial and wasn't widely-accepted. His hypothesis that the continents are slowly drifting around the Earth (German (de): Kontinentalverschiebung) went largely ignored. However, it became widely accepted in the 1950s, when several discoveries proved right of Alfred's theory, including palaeomagnetism.
Evidence to Support
 
Harry Hess in the Navy

Seafloor Spreading

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Seafloor Spreading is the process when new oceanic lithosphere forms due to the rising and solidifying of magma. As tectonic plates move away from each other, new crust (magma, then solidified) fills in the gap between the moving sea floors. This new crust forms underwater mountain systems called mid-ocean ridges. The new crust pushes away the older crust, thus, the closer to the mid-ocean ridge, the younger the crust is.

Evidence to support Seafloor Spreading: Magnetic Reversals

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Magnetic Reversals are defined as: "A change in the Earth's magnetic field (the North Pole --> South Pole, and vice versa)".