A horst is a raised block of the Earth's crust that is bounded by faults on its two sides. The faults on both sides of a horst are typically normal faults, which occur when the rock on one side of a fault moves downward relative to the rock on the other side. This can result in the formation of a rift valley between the two faults. Reversed faults, on the other hand, occur when the rock on one side of a fault moves upward relative to the rock on the other side. Tear faults are also known as transform faults, and they occur when two tectonic plates slide past each other horizontally. Thrust faults are characterized by rocks being pushed up and over other rocks, resulting in a ramp-like structure. However, in the context of a horst, normal faults are the most common type of fault found on both sides.