GEO 303 Lecture Notes - Lecture 3: Continental Drift, Lystrosaurus, Mesosaurus
11 Nov 2016
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Continental drift: 1915: alfred wegener proposed continental drift. The continents were once connected together in a massive supercontinent called. Observation: continents look like they fit together in jigsaw pieces. People thought that the earth was shrinking and that"s why mountains came about: wegener"s hypothesis. Isotopic ages match as well: faults and other structural features can also be traced across now widely separated continents. Mountain ranges- some mountain ranges of similar ages line up when the continents are pushed back together: tend to occur in belts- along margins of continents in bands. Not everywhere, but some seem to have similar structure. Scientific bias of the time (germans weren"t very popular in the 1920s) wegener was an outsider: additional support for wegener"s hypothesis. Apparent polar wander: appearance that the pole is wandering when in reality it is the continents moving towards you. Continents not just moving, also rotating when they move.
