thumb|349x349px|Simple model for transpression: strike-slip zone with an additional and simultaneous shortening across the zone. Also induces vertical uplift. In geology, transpression is a type of strike-slip deformation that deviates from simple shear because of a simultaneous component of shortening perpendicular to the fault plane. This movement ends up resulting in oblique shear. It is generally very unlikely that a deforming body will experience "pure" shortening or "pure" strike-slip. The relative amounts of shortening and strike-slip can be expressed in the convergence angle alpha whic
thumb|349x349px|Simple model for transpression: strike-slip zone with an additional and simultaneous shortening across the zone. Also induces vertical uplift. In geology, transpression is a type of strike-slip deformation that deviates from simple shear because of a simultaneous component of shortening perpendicular to the fault plane. This movement ends up resulting in oblique shear. It is generally very unlikely that a deforming body will experience "pure" shortening or "pure" strike-slip. The relative amounts of shortening and strike-slip can be expressed in the convergence angle alpha which ranges from zero (ideal strike-slip) to 90 degrees (ideal convergence). During shortening, unless material is lost, transpression produces vertical thickening in the crust. Transpression that occurs on a regional scale along plate boundaries is characterized by oblique convergence. More locally, transpression occurs within restraining bends in strike-slip fault zones.
== Transpressional structures == Transpressional shear zones are characterized by an association of structures that suggest zone-normal shortening and zone-parallel shearing. Commonly developed features include transposition foliations, lineations, stylolites, folds, and reverse faults. Pure shear-dominated transpression usually gives steep lineations, while simple shear-dominated transpression favors horizontal lineations. It is also common for non-vertical transpressional zones to have a significant component of shearing parallel to the dipline of the zone boundary. In these zones, the lineations are between horizontal and vertical. The complete geometry presented by all structural elements in the zone is used to constrain the actual boundary displacements.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).