Sea Floor, Earth Plates Moving

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Section 3 Review

1. What was Wegener's theory of continental drift?
-Wegener's hypothesis was that all continents had once been joined together and have since drifted. 2. How did Wegener use evidence based on fossils to support his theory that the continents had moved? -Because it states, for exampe, fossils of the reptiles Mesosarus and Lystrosaurus have been found in places now seperated by oceans. Neither reptile could have swum great distances accross salt water. It is therefore likely these reptiles lived on a singlelandmass that has since split apart. 3. What was the main reason scientists rejected Wegener's theory of continental drift? - Wegener could not provide satisfactory explanation for the force that pushes and pulls the continents. 4. Two pieces of land got seperated and one became Antartica, it drifted far from the equator in which the coal froze from the drop in tempature.

Section 4 Review

1. What is the role of the mid-ocean ridge in sea-floor spreading? - Hess suggested that the ocean floors move like conveyor belts, carrying the continents along with them. This movement begins at the mid-ocean ridge. At the mid-ocean ridge, molten material rises from the mantle and erupts. The molten material then spreads out, pushing older rock to both sides of the ridge. 2. What is the evidence for sea-floor spreading?

-Hess called the process that continually adds new material to the ocean floor sea-floor spreading. He relized that the sea floor spreads apart along both sides of the mid-ocean ridge as new crust is added. 3. Describe the proccess of subduction at a deep-ocean trench. -At deep-ocean trenches, subduction allows part of the ocean floor to sink back into the mantle, over tens of millions of years. 4. Where would you expect to find the oldest rock on the ocean floor? Explain your answer. - At the sides of the ridge, and or ontop-ish.

5. As you can see in Figure 15, the mid-ocean ridge extends into the Red Sea between Africa and Asia....
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