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12 Cards in this Set

  • Front
  • Back
What did Alfred Wegener propose?
The continental drift hypothesis in 1915
What book did Wegener publish?
The Origin of Continents and Oceans
What is the continental drift hypothesis?
A supercontinent called Pangaea began breaking apart about 200 million years ago
In the Continental drift hypothesis the continents did what?
drifted to their present positions
What is some supporting evidence for the Contintental drift hypothesis?
1. the fit of the continents
2. fossil evidence
3. rock type and structural similarities
5.paleoclimatic evidence
What is one main objections to the continental drift hypothesis?
Lack of a mechanism for moving continents - a good hypothesis must be consistent with the basic principles of physics
How did Wegener inncorrectly suggest that continents broke through the ocean crust?
Must like ice breakers cut through ice
What particular part of the scientific community had strong opposition to this hypothesis?
among American scientists
Who came up with the Seafloor spreading hypothesis?
Harry Hess early 1960's
What heavy igneous rock dominates the crust beneath the oceans
what does the basalt igenous rock make up?
the oceanic crust
The continental crust is largely composed of...