Tectonic Plates

Theory of Plate Tectonics

Tectonics is a term from the Greek word tektonikos, which means construction. With this in mind, Alfred Wegener developed additional research on the theory of tectonic plates and the continental drift hypothesis. The theory of plate tectonics was not developed until the 1960’s, but was foreshadowed by Alfred Wegener; however, it was he who noticed that the African and South American coastlines, which are on opposite sides of the Atlantic Ocean, seem to fit as if they were puzzle pieces. Wegener was the first to pursue his observation with additional research and after close observation of various maps, he found that when other continents were moved just so, that they fit like puzzle pieces as well. He termed it a supercontinent, which he later called Pangea, which is the Greek root words for ‘all lands’. Pangea was then observed from the northern part, called Laurasia, and the southern part, called Gondwanaland. He knew this observation alone would not be enough to prove that a supercontinent had existed, but he worked from 1910, until his death in 1930, to find additional evidence to support his supercontinent theory.

Accordingly, Wegener mapped locations of fossils for species that could not swim well, nor fly. Fossils for these species can now be found in places such as Africa, Antarctica, Australia, South America, and India. He believes that the species, before Pangea broke apart, evolved and took root in those sections of Pangea. Next, Wegener plotted 250-million-year-old glacial deposits, and other climate-indicating rocks on his created Pangea map, illustrating their distribution in logical relation to the places of Pangea. Likewise, he noticed unique instances where rocks on one side of the map, mirrored those on the other where the continents are now broken apart. For instance, deformed rocks on the Cape Fold belt of South Africa are similar to those of the Buenos Aires province of Argentina; however, when plotted out on the...