Question

Earth’s crust continuously melts and solidifies in the upper mantle. Why does oceanic crust solidify faster than continental crust?

A Continental crust spans a wider area and is generally thinner than oceanic crust.
B Magma beneath oceanic crust is a lower temperature than magma beneath continental crust.
C When magma comes into contact with ocean water it cools faster than when it reaches continental rock.
D Salt in ocean water accelerates the solidification process by way of chemical reaction.

Answer 1

C When magma comes into contact with ocean water it cools faster than when it reaches continental rock.

Answer 2

The correct answer here is C. Water molecules are more free to move, so they will be able to engage in rapid and fluid contact with magma. This is in contrast to fixed continental rock, which may have quick initial heat transfer but which tapers off quickly because the rock is not flexible enough to send cooler rock towards the magma.