Final answer:
The statement is false. Faults can exhibit a combination of strike-slip and dip-slip motions, known as oblique slip faults, depending on the tectonic forces.
Step-by-step explanation:
The statement that motion along all faults is either strike slip or dip slip and that combinations of these two types of displacement are never found together in a single fault is false. It is not uncommon to find faults with a combination of strike-slip and dip-slip motion, also known as oblique slip faults.
The blocks on either side of a fault are called the footwall and the hanging wall. In normal faults, the hanging wall moves down due to extension, whereas in reverse faults and thrust faults, the hanging wall moves upwards due to compressional forces, with thrust faults having a gentle dip of less than 30°.
Strike-slip faults exhibit horizontal motion, and the fault orientation is vertical. However, complex fault systems can reflect a combination of different movements depending on the tectonic forces involved.