Deformation is said to be the change in shape, texture or pattern of a particular body. In relation to geography, the rock becomes the body. It might be extensive as in geologic structure like folds and faults or noticeable on a smaller scale as in clay bodies.
Usually, increase in temperature(heat) and pressure supports ductile deformation, the rocks structure for example folds gain the ability to bend without breaking . The high temperature and pressure experience in the earths warranted the ductility.
Lower temperature and pressure support brittle deformation , with limited stress the rock structure breaks.
