Visual Glossary

A reverse fault.

Reverse fault

We classify faults by how the two rocky blocks on either side of a fault move relative to each other. The one you see here is a reverse fault. Along a reverse fault one rocky block is pushed up relative to rock on the other side.

Here's a way to tell a reverse fault from a normal fault. Take a look at the side that shows the fault and arrows indicating movement. See the block farthest to the right that is shaped kind of like a foot? That's the foot wall. Now look at the block on the other side of the fault. See how it's resting or hanging on top of the foot wall block? That's the hanging wall.
Think about this: if we hold the foot wall stationary, where would the hanging wall go if we reversed gravity? The hanging wall will slide upwards, right? When movement along a fault is the reverse of what you would expect with normal gravity we call them reverse faults!