Fault blocks rotate through a result of tectonic plates extending apart. When its upper lithospheric crust goes through extensional pressures, the brittle crust of the Earth breaks apart, this creates the fault blocks. Earth's crust is partially collapsed down and pushed up.

Non-rotating fault blocks are neighboring standard faults that dive in opposite directions and trim the crust into wedge shaped faulted blocks. When there's motion through the faults there are blocks that drop which creates the sedimentary basins. A mountain forms on top known as a horst, erosion to this mountain helps the sediment to the basins. Eventually the mountains are eroded.