Which fault occurs when slabs of rock move past each other in opposite directions?

• A. Strike-Slip Fault
• B. Normal Fault
• C. Reverse Fault
• D. Caldera

Answer: (A)

When slabs of rock move past each other in opposite directions, the movement is mainly horizontal along a vertical fault plane. That describes a strike-slip fault, where the blocks slide side by side rather than moving up or down. The direction can be right-lateral or left-lateral depending on perspective, but the key idea is the lateral shift.

The other ideas involve vertical movement: a normal fault occurs when the crust stretches and the hanging wall drops relative to the footwall; a reverse fault happens under compression with the hanging wall moving up; a caldera is a volcanic collapse feature, not a fault type. So the horizontal, side-by-side motion defines the strike-slip fault.