GEOL 101 Lecture Notes - Lecture 2: Eurasian Plate, Continental Crust, Outer Core
11 Jan 2017
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Document Summary
Continental drift: large-scale horizontal movements cause earth"s major topographical features such as mountains and oceans basins. Alfred wegener (1880-1930: proposed in 1912 based on observation of drifting ice sheets. Geographic fit of the continents, one of the first pieces of evidence used to argue for continental drift. Paleontologists: animals and plants diverge in evolution after the postulated breakup time. Initially rejected by geologists: new data after wwii led to 1960"s plate tectonic revolution, ocean drilling. Seafloor spreading: convection in the earth"s mantle could break up and push continents apart. Harry hess (1906-1969): got the credit for holmes" idea. He used the hypothesis of mantle convection to explain seafloor spreading, island arcs, gravity, anomalies and serpentine rocks. Rifting: when the continental rock heats up and spreads apart, is continental rifting, creates a new ocean basin between. Iceland: an opening rift on the mid-atlantic ridge. Their locations are predicted by plate tectonics.
