Fractures are mechanical breaks in rocks; they originate from strains that arise from stress concentrations around flaws, heterogeneities, and physical discontinuities. They form in response to lithostatic, tectonic, and thermal stresses and high fluid pressures. They occur at a variety of scales, from microscopic to continental.
Fractures are important in engineering, geotechnical, and hydrogeological practice because they provide pathways for fluid flow. Many economically significant petroleum, geothermal, and water supply reservoirs form fractured rocks. Fracture systems control the dispersion of chemical contaminants into and through the subsurface. They also affect the stability of engineered structures and excavations.
A Review of hydraulic structure and rock formation fluid flow systems