Final answer:
An oblique-slip fault is characterized by displacement that is neither parallel to the fault's strike nor its dip, involving both horizontal and vertical components of motion.
Step-by-step explanation:
If the displacement on a fault is neither parallel to the strike nor to the dip, then the fault in question is an oblique-slip fault. The blocks on either side of a fault are known as the walls, and the nature of their movement characterizes different types of faults. A strike-slip fault has a vertical orientation with horizontal displacement between walls. In comparison, a dip-slip fault's movement is vertical, and the walls are defined as the footwall or the hanging wall. The dip-slip motion can be downwards in normal faults, which are formed during extension, or upwards in reverse faults, which occur due to compression.
A thrust fault is a special type of reverse fault with a gentle dip of less than 30 degrees, where the allochthonous block is thrust over the autochthonous block. Oblique-slip faults combine elements of both strike-slip and dip-slip motion, and are thus not exclusively parallel to either the fault's strike or dip. This inclined motion can occur during various tectonic processes and can significantly alter the landscape over geological time scales.