Plate Tectonics

Plate Tectonics

The idea of plate tectonics began with the idea of continental drift. Originally, the idea that the continents move was proposed by American F.B. Taylor in 1910. His paper lacked supporting evidence and so was largely ignored by the scientific community. In 1915, Alfred Wegener published the book The Origin of the Continents and Oceans in which he again proposed the idea of continental drift. He also proposed the idea of a supercontinent called Pangaea. Support for these ideas included fossil distributions, biogeography, rock structures, ancient climates, and continental shape.

Fossil Evidence

• The fossil of the mesosaurus are found in the rocks of South America and Africa.
• The mesosaurus is assumed to be an aquatic, snaggle-toothed reptile.
• If this organism could swim well enough to make it across the Atlantic Ocean, then why aren't the fossils distributed in other areas.

Biogeographical Evidence

• Many modern animals with similar ancestries are found on different continents. This lends supporting evidence to a supercontinent.

Rock Structures

• The rocks and geological features on separate continents fit together and seem to be a part of the same formation.
  • Example: The Appalachian Mountain chain of North America is similar in age and structure to the rocks found in the British Isles nad Scandanavia.

Ancient Climates

• Evidence of ancient climates is seen throughout the world with glacial grooves and glacial till. If the landmasses were connected in a supercontinent, the glacial deposits found in the new Southern Hemisphere is logically explained.

Wegener's idea of continental drift was largely rejected by the science community because Wegener could not provide a plausible mechanism capable of moving the continents.

With increased scientific data and technology like ocean mapping and seismic activity data, the theory of plate tectonics began to develop.