ASBOG Practice Exam

What type of fault is a detachment fault?

1. Low angle reverse fault

2. Low angle normal fault

3. High angle strike-slip fault

4. Normal strike-slip fault

The correct answer is: Low angle normal fault

A detachment fault is characterized as a low angle normal fault. This type of fault typically occurs in areas undergoing extension, where the crust is being pulled apart. In a detachment fault, the hanging wall moves downward relative to the footwall along a low-angle surface, allowing for significant horizontal movement. This mechanism results in the development of a distinct geological feature where the hanging wall can rotate and create a series of stratigraphic relationships that differ from the footwall. The essential aspect of a detachment fault is its low-angle nature, usually less than 30 degrees, which distinguishes it from other types of faults. This geometry contributes to unique geological settings and can lead to the formation of large orogenic belts as seen in regions of tectonic extension. Understanding detachment faults is crucial for interpreting extensional tectonics and related geological processes.