What direction was the Pacific plate moving between 65 and 43 ...

[mp14]

What direction was the Pacific plate moving between 65 and 43 million years ago?
 
  A) North
  B) Southeast
  C) East
  D) West
  E) Northwest

Question 2

Using the block diagram provided, explain how new plate material is created at a divergent plate boundary. Make sure your answer includes a discussion on the forces at work and the generation of magma beneath the rift.
 
  What will be an ideal response?

[Bsand8]

Answer to Question 1

Answer: A

Answer to Question 2

Answer: Tensional stress pulls the plates apart, creating a rift between them. The creation of the rift means that there is not as much force (the weight of the overlying plates) pushing down on that part of the mantle, which results in decompression melting that generates magma. Magma is less dense than the surrounding rock and rises up, filling the gap between the two plates. However, the plates are still being pulled apart, so the new material is also pulled apart, with part of it adhering to each plate.