Which term describes a force that causes deformation in rocks?

The term that describes a force that causes deformation in rocks is stress. Stress refers to the force exerted per unit area on a material. When rocks are subjected to different types of stress—such as tension (pulling apart), compression (squeezing), or shear (sliding past each other)—they can deform in various ways, leading to changes in their shape or volume.

Stress is a fundamental concept in geology and Earth science as it helps explain how and why rocks undergo deformation over time, which is crucial in understanding geological processes like the formation of mountains, earthquakes, and other tectonic activities.

In contrast, tension and compression are specific types of stresses, while strain refers to the response of the rock to the applied stress, describing the deformation that occurs as a result of that stress. Thus, stress is the overarching term that encompasses various forces leading to deformation in rocks.