238 History of Plate Tectonics

Discover the journey of plate tectonics! Learn about Wegener's theories and modern discoveries.

Abraham Ortelius was one of the first people to recognize that the continents looked as if they fit together like a puzzle. Scientists believed mountains formed when the land cooled and wrinkled. This was called the Raisin Theory. Alfred Wegener found evidence of the same fossils of plants and animals existing on different sides of the ocean. This along with the idea that the continents looked like puzzle pieces led to his hypothesis that the land was once joined. What was the name of Wegener's Theory? Continental DriftWhat was the name used to describe when all of the landmasses were joined together? Pangaea Not all theories are accepted by other scientists. The Theory of Continental Drift was not accepted because Wegener could not explain how the continents moved. New technology in the form of sonar led to the discovery that the ocean floor is actually mountainous. An underwater mountain range is called a mid - ocean ridge.The discovery of differing magnetism along the seafloor led scientists to believe the seafloor was spreading along the mid ocean ridge.Henry Hess proposed that new crust was being created along mid ocean ridges.More evidence came from mapping the location of earthquakes and volcanic activity. This new evidence led to the development of the Theory of Plate Tectonics. Wegener was wrong in his theory in that he thought the continents moved. We now know that the continents and ocean floor float on the asthenosphere. Drag and DropDrag the evidence into the correct category. It either represents the Theory of Continental Drift or is new evidence for the Theory of Plate Tectonics. Wegener's Evidence Climate Evidence Puzzle Pieces Matching Mountains Fossils New Evidence Mapping of Earthquakes Mapping of Volcanoes Discovery of Mid Ocean Ridge Seafloor Spreading You've been invited to a Quizizz game