In convergent geodynamic settings, extensional and compressional tectonics occur contemporaneously or in different times and places, but they are deeply linked to each other in a number of different ways. The main types of extensional regimes here considered are for west-dipping subduction zones: (1) back-are extension (e.g., Tyrrhenian Sea); (2) uplift and related extension due to asthenospheric wedging (e.g., Apennines); (3) extension at the subduction hinge (e.g., Marianas); (4) extension due to increasing length of arcs (e.g., Apennines). For east-, northeast- or north-northeast-dipping subduction zones: (5) extension induced by collapse of orogens (e.g., Alps, Himalayas); (6) extension induced by differential lithosphere-asthenosphere coupling in the hanging wall of a subduction zone (e.g., Aegean rift); (7) rifting induced by orogenic roots anchored into the mantle (e.g., Atlantic and Tethys). Other types may be considered: (8) inversion of plate motion, from convergent to divergent relative plate vectors due to external velocity fields (e.g., Basin and Range); (9) transtension may occur along oblique ramps of thrust area due to differential forward propagation of thrusts planes (e.g., southern arm of the Barbados accretionary prism?); transtension and transpression also occur contemporaneously along an undulate strike-slip setting, or extension can accompany foreland dipping duplexes; (10) apparent extension due to down-section cut of thrust planes along subduction zones. Each type of extension generates different shape, depth and relationships between hanging wall and footwall of the associated normal faults and shear zones.
