What defines brittle deformation?

Brittle deformation is characterized by a permanent change in the material that results in cracking or fracturing when the stress applied exceeds the material's strength. This type of deformation typically occurs in rocks or materials that are not very ductile, meaning they cannot easily change shape without breaking. When the conditions are right, such as in response to tectonic forces, brittle deformation can lead to the formation of faults or fractures in the Earth's crust.

The distinction between brittle and other forms of deformation, such as ductile or elastic deformation, is crucial. In the case of ductile deformation, materials change shape under stress but do not break, while elastic deformation is temporary and the material returns to its original shape once the stress is removed. Therefore, the key aspect of brittle deformation is the irreversible change indicated by cracking and the inability to revert to the original configuration.