Final answer:
Subsurface thrusts are thrust faults that do not reach the surface. They occur when rock layers are forced over each other, with the older rock layers being thrust over the younger ones.
Step-by-step explanation:
Thrust faults that do not reach the surface are called subsurface thrusts. These faults occur when rock layers are forced over each other, with the older rock layers being thrust over the younger ones. They are often responsible for the formation of mountain ranges and can be found in various parts of the world.