Detachment fault

One group of scientists defines detachment faults as follows: "The essential elements of extensional detachment faults, as the term is used here, are low angle of initial dip, subregional to regional scale of development, and large translational displacements, certainly up to tens of kilometres in some instances."

[5] The hanging wall, composed of extended, thinned and brittle crustal material, can be cut by numerous normal faults.

[8] However, slip on low angle normal faults could be facilitated by fluid pressure, as well as by weakness of minerals in wall rocks.

[7] While occurring at relatively amagmatic spreading centres, the footwalls of these detachment faults are much more influenced by magmatism than in continental settings.

In fact, they are often created by 'continuous casting': new footwall is continually being generated by mantle or melt from a magma chamber as slip occurs on the fault.

[7] The lithology is dominated by gabbro and peridotite, resulting in a mineralogy of olivine, serpentine, talc and plagioclase.