Fault gouge is a type of fault rock best defined by its grain size. It is found as incohesive fault rock (rock which can be broken into its component granules at the present outcrop, only aided with fingers/pen-knife), with less than 30% clasts >2mm in diameter.[1] Fault gouge forms in near-surface fault zones with brittle deformation mechanisms. There are several properties of fault gouge that influence its strength including composition, water content, thickness, temperature, and the strain rate conditions of the fault.
- ^ Woodcock, NH; Mort, K (2008). "Classification of fault breccias and related fault rocks". Geological Magazine. 145 (3): 435-440. doi:10.1017/S0016756808004883. S2CID 55133319.