1.4

Question 1

What is paleomagnetism?

Answer 1

• lava contains magnetic minerals
• while lava cools, minerals align with magnetic field
• reverses direction every 200,000 years
• direction of mineral deposition also reverses

Question 2

What can be observed due to paleomagnetism?

Answer 2

• Symmetrical patterns either side of a mid ocean ridge can be observed as rock moves away from mid ocean ridge.

Question 3

What is the asthenosphere?

Answer 3

• Layer between crust and mantle
• Formed of semi molten rocks

Question 4

What is slab pull?

Answer 4

The side of the plate at the subduction zone is pulled under the other plate

Question 5

What is sea floor spread?

Answer 5

Lava continuously rises to surface
Cools and forms new rock on edges of plate

Question 6

At what type of plate boundary does sea floor spread occur?

Answer 6

Constructive

Question 7

What is magma?

Answer 7

Partially molten mantle rock

Question 8

What is ridge push?

Answer 8

Mid ocean ridge gets heavy
Slides downwards in opposite directions