The theory of plate tectonics is supported by . The Eurasian and African plate are pushed away from the North and South American Plates at the . is where rocks are carried back into the mantle of the earth. iron can be magnetized by the magnetism of the earth. Subduction of the ocean floor occurs in . Respond to the following based on your reading. Why have rocks older than 200 million years never been found in the oceans? Explain how the movement of tectonic plates is responsible for this recycling of the ocean floor.

1. ridges and trenches (either answer is acceptable)

2. mid-atlanitc

3. subduction zone

4. molten

5. oceanic trenches

Explain:

6. Rocks in the ocean eventually get subducted back into earths mantle due to slab pull. New rocks form at mid-ocean ridges as ridge forces two plates to diverge.

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.