ASBOG Practice Exam

In a normal fault, which direction does the hanging wall move?

1. Downward

2. Upward

3. Horizontally

4. Diagonally

The correct answer is: Downward

In a normal fault, the hanging wall moves downward relative to the footwall. This downward movement occurs because the tectonic forces acting on the crust are pulling it apart, which leads to the extension and thinning of the crust. As a result, the rock mass above the fault plane (the hanging wall) is forced down, while the rock mass below it (the footwall) remains in place or may even move slightly upward. This type of faulting is commonly associated with divergent tectonic plate boundaries, where two plates are moving away from each other, allowing for the characteristic downward movement of the hanging wall. Understanding this movement is essential for interpreting geological structures and the tectonic history of an area.