Which term describes a permanent and gradual change in shape or volume of a material due to stress?

The term that describes a permanent and gradual change in shape or volume of a material due to stress is ductile deformation. This phenomenon occurs when a material is subjected to prolonged stress, causing it to undergo deformation that is not recovered when the stress is removed. Ductile deformation typically happens in materials that can deform plastically, such as certain types of rocks under high temperature and pressure conditions.

In contrast, elastic deformation refers to a temporary change in shape or volume where the material returns to its original state once the stress is removed. A normal fault is a type of geological fault that occurs when the crust is extended, leading to one block of rock moving downward relative to another, which does not pertain to gradual changes in shape or volume of materials under stress. A geologic map is a representation of geological features in an area and does not directly relate to the concepts of deformation under stress. Understanding ductile deformation is essential in geology, especially in the study of tectonics and the behavior of rocks under stress within the Earth’s crust.