In
geology the term
compression refers to a set of stresses directed toward the center of a rock mass.
Compressive strength refers to the maximum
compressive stress that can be applied to a material before failure occurs. When the maximum compressive stress is in a horizontal orientation,
thrust faulting can occur, resulting in the shortening and thickening of that portion of the
crust. When the maximum compressive stress is vertical, a section of rock will often fail in
normal faults, horizontally extending and vertically thinning a given layer of rock. Compressive stresses can also result in
folding of rocks. Because of the large magnitudes of lithostatic stress in
tectonic plates, tectonic-scale
deformation is always subjected to net compressive stress.