Thick-skinned deformation

Thick-skinned deformation specifically affects deep crystalline rock of the basement and may extend deeper into the lower crust.

[1] Thick-skinned deformation is most commonly a result of crustal shortening and occurs when the region is undergoing horizontal compression.

This frequently occurs in at the sites of continental collisions where orogenesis, or mountain building, is taking place and during which the crust is shortened horizontally and thickened vertically.

This fracture cuts across layers of rock to form a ramp which will allow movement to dissipate the accumulated strain.

When this occurs in a collisional zone then the rock can be deformed by creep and will behave similarly to a fluid over the long periods of geologic time.

Diagram of the thick-skinned deformation of a thrust-fault.
Diagram of the thin-skinned deformation of a thrust-fault.
Continent-continent collision
Diagram of the evolution of a thrust-fault.
NASA Landsat-7 imagery of Himalayas