Fracture (geology)
In geology, a fracture is any kind of separation or break in a rock formation. Examples are joints or faults. These divides the rock into two or more pieces.[1] A fracture can sometimes form a deep, wide crack in the rock. They are usually caused when the rock is not strong enough to hold up under too much stress. This makes the rock crack along its weakest point.[2] Fractures can provide access for fluids, like water or hydrocarbons, to move into the rock.
Fracture (geology) Media
Rough surfaces on a piece of fractured granite
Shear fracture (blue) under shear loading (black arrows) in rock. Tensile cracks, also referred to as wing cracks (red) grow at an angle from the edges of the shear fracture allowing the shear fracture to propagate by the coalescing of these tensile fractures.
2D Mohr's diagram showing the different failure criteria for frictional sliding vs faulting. Existing cracks orientated between -α/4 and +α/4 on the Mohr's diagram will slip before a new fault is created on the surface indicated by the yellow star.
Three dimensional computer model of a fracture and fault network (DFN/DFFN), showing the different geological sets in colours, generated by the DMX Protocol using a combination of probabilistic and deterministic procedures
References
- ↑ Gudmundsson, Agust (2011) Rock Fractures in Geological Processes Cambridge University Press, Cambridge, England, ISBN 978-0-521-86392-6
- ↑ Park, R. G. (2005) Foundation of Structural Geology (reprint of the 1997 Chapman and Hall edition) Routledge, Abingdon, England,page 9, ISBN 978-0-7487-5802-9
