Understanding Plate Tectonics

Front

In sea-floor spreading, molten material rises from the mantle and erupts

Back

along mid-ocean ridges.

Front

The process by which the ocean floor sinks beneath a deep-ocean trench and back into the mantle is known as _______

Back

subduction.

Front

Most geologists think that the movement of Earth’s plates is caused by _______

Back

convection.

Front

A place where two plates slip past each other, moving in opposite directions, is known as a _______

Back

transform boundary

Front

Scientists think that convection currents flow in Earth’s

Back

mantle.

Front

The place where two plates come together is known as a _______

Back

convergent boundary.

Front

Below is a picture of sea-floor spreading. How are the ocean crusts moving?

Back

Diverging

Front

The San Andreas Fault in California is known as an active earthquake area. What type of boundary is it?

Back

Transform

Front

Where would the oldest rock be found?

Back

O

Front

How is it possible for new crust to be formed without increasing the surface area of the Earth?

Back

Crust is destroyed at the same time it is created.