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Continental Drift Theory Created
Alfred Wegener originally presented his hypothesis to the German Geological Society on this date. (http://en.wikipedia.org/wiki/Alfred_Wegener) -
Continental Drift Hypothesis Officially Presented
(The month and day are not true, there is no way to just have the year.) Alfred Wegener officially presents his hypothesis that the continents were once a large supercontinent, which he called Pangaea. This was met with ridicule from his scientist colleagues, because he could not explain how the continents moved. -
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Continental Drift Theory Rejected
Many scientists rejected Alfred Wegener's hypothesis for around fifty years. They rejected it because Wegener could not explain how the continents would move, and the guesses he gave seemed ridiculous to them. It wasn't until the discovery of plate tectonics that they believed him. -
Wegener's Evidence (Source: Textbook)
Alfred Wegener had evidence that he believed proved the occurence of continental drift. He found that there were matching fossils of a fresh water reptile on South America and Africa, and fossils of a fern on those two continents and India. There is no possible way that they could exist on seperate continents at the same time. He also discovered that certain mountain ranges on different continents lined up. Lastly, he found evidence of a different climate than what it is today on the continents. -
Pre-Plate-Tectonics-Theory-Theory
A man named Arthur Holmes, who was an English geologist, proposed in 1920 that the land under the sea may be broken up into "plate junctions". In 1928 he suggested that these plates may move because of convection currents within the mantle. His theory was partially true, but it was ignored because Wegener's hypothesis was still being rejected. (http://www.amnh.org/education/resources/rfl/web/essaybooks/earth/p_holmes.html) -
du Toit and the Book of Support
Alexander du Toit, who supported Wegener's hypothesis, published a book that explained his hypothesis in more detail. The book is titled "Our Wandering Continents". However, his own hypothesis differed from Wegener's. He believed that there were two supercontinents, Laurasia and Gondwanaland. (http://people.wku.edu/charles.smith/chronob/DUTO1878.htm) -
Sea-Floor Spreading Hypothesis Created
Geologist Harry Hess published his hypothesis on sea-floor spreading, which stated that new ocean floor is created along ridges in the ocean, and old ocean floor sinks back into the mantle. Evidence for this hypothesis includes the magnetic strips in the rock on the ocean floor, earthquake patterns, and the age of the ocean floor. Source: Textbook -
J. Tuzo Wilson Begins A Revolutionary Discovery
Tuzo Wilson, who was a supporter of Harry Hess's sea-floor spreading and Wegener's continental drift, developed a new theory that could explain how the continents moved. He suggested that the lithosphere was broken up into sections, called plates. He theorized that these plates moved slowly, powered by currents in the mantle. Source: Textbook
