Question

The displacement of the bed shown in the figure bellow is caused by a single movement along fault XYZ. Of the options given below, which fault-type can explain the observed displacement?

• A. Strike-slip
• B. Reverso
• C. Normal
• D. Trace-slip

Answer 1

The Correct Option is A

The question centers on identifying the type of fault that causes the observed displacement along fault XYZ. To determine the correct fault type, we need to analyze the characteristics of different types of faults.

1. Strike-slip Fault: This type of fault is characterized by horizontal movement along the fault plane. The blocks on either side of the fault slip past one another sideways, with little to no vertical movement. Observing the displacement in the diagram, both sides of the fault XYZ show horizontal displacement, which suggests a strike-slip fault.
2. Reverse Fault: This fault involves vertical displacement where the hanging wall moves upwards relative to the footwall. This is usually caused by compressional forces. The diagram does not indicate the typical upward displacement of a reverse fault.
3. Normal Fault: In contrast to reverse faults, a normal fault features vertical displacement where the hanging wall moves downward relative to the footwall, caused by extensional forces. The movement is not evident in the diagram.
4. Trace-slip Fault: The term "trace-slip" is often used incorrectly; the correct term is “strike-slip.” Hence, it’s not a separate fault type considered in geology examinations.

Based on the analysis of the available options and the characteristics of the observed displacement, the correct answer is a Strike-slip fault. This fault type aligns with the horizontal movement demonstrated in the image.