What best describes tectonic force

Tectonic Forces

Rocks are under stress when they are subjected to a force at depth. When the rocks are exposed at the surface after uplift and erosion, the effects of the stress can be studied. Stressed rocks show varying degrees of strain-the change in the volume and/or shape of the rock because of that stress. For example, a volcanic agglomerate may be compacted and its pyroclastic fragments stretched (strained) in response to a tectonic stress, such as compression.