Inversion (geology)

Section across southern England showing the inverted nature of the Channel and Weald basins
The Quantocks Head Fault, west of Kilve, Somerset, showing the effects of inversion on the earlier normal fault, with folding and thrusting in the hanging wall

In structural geology, inversion or basin inversion relates to the relative uplift of a sedimentary basin or similar structure[example needed] as a result of crustal shortening. This normally excludes uplift developed in the footwalls of later extensional faults, or uplift caused by mantle plumes. "Inversion" can also refer to individual faults, where an extensional fault is reactivated in the opposite direction to its original movement.

The term negative inversion is also occasionally used to describe the reactivation of reverse faults and thrusts during extension.

The term "inversion" simply refers to the fact that a relatively low-lying area is uplifted – the rock sequence itself is not normally inverted.