1.4 Flashcards
1
Q
What is paleomagnetism?
A
- lava contains magnetic minerals
- while lava cools, minerals align with magnetic field
- reverses direction every 200,000 years
- direction of mineral deposition also reverses
2
Q
What can be observed due to paleomagnetism?
A
- Symmetrical patterns either side of a mid ocean ridge can be observed as rock moves away from mid ocean ridge.
3
Q
What is the asthenosphere?
A
- Layer between crust and mantle
- Formed of semi molten rocks
4
Q
What is slab pull?
A
The side of the plate at the subduction zone is pulled under the other plate
5
Q
What is sea floor spread?
A
Lava continuously rises to surface
Cools and forms new rock on edges of plate
6
Q
At what type of plate boundary does sea floor spread occur?
A
Constructive
7
Q
What is magma?
A
Partially molten mantle rock
8
Q
What is ridge push?
A
Mid ocean ridge gets heavy
Slides downwards in opposite directions
