A fracture is a break or crack in a rock where there has been no significant movement of the rock on either side of the crack. Fractures can occur due to stress, temperature changes, or other geological processes. They are significant in structural geology, hydrogeology, and petroleum geology, as they can influence fluid flow, rock strength, and the migration of hydrocarbons.
Reference: Pollard, D. D., & Aydin, A. (1988). Progress in Understanding Jointing over the Past Century. Geological Society of America Bulletin.