What style of faulting may occur when the Horizontal Stress is greater than the vertical stress?

What style of faulting may occur when the Horizontal Stress is greater than the vertical stress?

• A. Normal faulting
• B. Strike-slip faulting
• C. Reverse/Thrust faulting
• D. Oblique-slip faulting

Answer: (C)

When horizontal stress is greater than vertical stress, the rocks are being squeezed side to side. In this compressive regime, the crust shortens vertically and accommodates the force by a dip-slip motion where the hanging wall moves upward relative to the footwall. That is the hallmark of a reverse fault, and when the fault plane is relatively shallow, it’s described as a thrust fault. This contrasts with normal faulting, which arises under extension and features the hanging wall dropping, and with strike-slip faulting, which is dominated by horizontal shear with little vertical displacement. Oblique-slip faults involve both dip-slip and strike-slip components, but the primary response under dominant horizontal compression is reverse/thrust faulting.

When horizontal stress is greater than vertical stress, the rocks are being squeezed side to side. In this compressive regime, the crust shortens vertically and accommodates the force by a dip-slip motion where the hanging wall moves upward relative to the footwall. That is the hallmark of a reverse fault, and when the fault plane is relatively shallow, it’s described as a thrust fault. This contrasts with normal faulting, which arises under extension and features the hanging wall dropping, and with strike-slip faulting, which is dominated by horizontal shear with little vertical displacement. Oblique-slip faults involve both dip-slip and strike-slip components, but the primary response under dominant horizontal compression is reverse/thrust faulting.