What substance was able to show previous orientations of Earth's ...

[notis]

What substance was able to show previous orientations of Earth's magnetic field?
  a. Magma
  b. Basalt
  c. Magnetite
  d. Magnesium

Question 2

What keeps Earth's asthenosphere pliable?
  a. Chemical composition of the asthenosphere
  b. The density of the asthenosphere
  c. Earth's internal heat
  d. Insulation from the lithosphere

[Jevvish]

Answer to Question 1

ANS: C
Magnetite is in the mantle. When new crust is formed, the magnetite is in that crust. As it cools, it
points in the direction of the current magnetic field of the Earth. This allowed scientists to determine
the direction of magnetic fields throughout history. Information can be found in the section The
Confirmation of Plate Tectonics

Answer to Question 2

ANS: C
The asthenosphere remains pliable due to the internal heat of the Earth. This heat is thought to travel
through the Earth's interior via conduction. The lithosphere is able to remain in motion because of that
pliability. Information can be found in the section A New Understanding of Earth Evolved Slowly.