This type of faulting occurs in response to extension and is often observed in the Western United States Basin and Range Province and along oceanic ridge systems. 这种类型的断层活动是由伸展作用造成的，常常在美国西部的盆岭省以及海底洋岭系统中观测到。
A possible mechanism for the generation of deep focus earthquakes is faulting caused by olivine undergoing a phase transition into a spinel structure. 发生深层震源地震的机制可能是由于橄榄石经历了到针状结构的相变而产生的断层作用。
