Which type of stress involves squeezing rocks?

The type of stress that involves squeezing rocks is compression. This occurs when forces act to push the rock material together, resulting in a decrease in volume and often leading to changes in the rock's shape and structure. In geological terms, compression is a fundamental force that can cause folding and faulting of Earth's crust as tectonic plates collide or as overlying rock layers exert pressure on underlying materials.

In contrast, tension refers to the stress that pulls rocks apart, which leads to stretching and thinning of the material. Shear stress involves forces that cause parts of a rock to slide past each other, typically resulting in lateral displacements. Elastic stress refers to the reversible deformation that occurs when materials are subjected to stress but returns to their original shape once the stress is removed, rather than causing permanent changes like compression does. Thus, compression is uniquely characterized by the application of forces that squeeze rocks, making it the correct identification for this type of stress.