What type of stress acts to push a mass of rock in opposite directions?

The correct answer is shearing, which refers to a type of stress where forces act parallel to each other, pushing a mass of rock in opposite directions. This kind of stress often occurs along fault lines where two plates are sliding past each other, causing deformation in the rock layers adjacent to the fault. Shearing can lead to the formation of features such as strike-slip faults, where the motion results in horizontal displacement.

Compression, on the other hand, involves forces that push rock masses together, typically leading to the folding or faulting of rocks. Tension is the opposite of compression; it pulls rocks apart, usually resulting in stretching or thinning of the crust. Bending pertains to the deformation of rocks under stress but does not exclusively describe the scenario of forces acting in opposite directions as shearing does. Therefore, shearing is distinctly characterized by this lateral motion, making it the defining type of stress for pushing rocks in opposite directions.