This model is developed based on the geological evolution of Alpine and Apennine subduction.<ref name=":103">{{Cite journal|last1=Vignaroli|first1=Gianluca|last2=Faccenna|first2=Claudio|last3=Jolivet|first3=Laurent|last4=Piromallo|first4=Claudia|last5=Rossetti|first5=Federico|date=2008-04-01|title=Subduction polarity reversal at the junction between the Western Alps and the Northern Apennines, Italy|journal=Tectonophysics|volume=450|issue=1–4|pages=34–50|doi=10.1016/j.tecto.2007.12.012|bibcode=2008Tectp.450...34V}}</ref>
Similarly, two oceanic plates move towards each other. The subduction process ceases with the involvement of buoyant continental block. A new slab is formed at the overriding plate owing to the regional compression and the difference in density between the continental block and oceanic plate.<ref name=":103" /> An [[orogenic wedge]] is built.<ref name=":103" /> However, there is an obvious space problem about how to accommodate two slabs. The solution is the new developing slab moves not only vertically, but also laterally leading to a deep strike-slip movement.<ref name=":103" /> The development of co-existence of two opposite slabs is described as a double sided subduction<ref>{{Cite journal|last1=Tao|first1=Winston C.|last2=O'connell|first2=Richard J.|date=1992-06-10|title=Ablative subduction: A two-sided alternative to the conventional subduction model|journal=Journal of Geophysical Research: Solid Earth|language=en|volume=97|issue=B6|pages=8877–8904|doi=10.1029/91JB02422|issn=2156-2202|bibcode=1992JGR....97.8877T}}</ref> or doubly convergent wedge.<ref name=":103" /> Eventually, the development of new slab grows and slides onto the old slab. The old slab breaks off and the orogenic wedge collapses. The new slab stops the lateral motion and subducts beneath.<ref name=":103" /> The direction of subduction system changes.<ref name=":103" />[[File:Doubly_Convergence.gif|thumb|457x457px|Evolution of doublydouble convergence model: Brown colour represents the Continental plate; White colour represents the oceanic plate; C1. The plate with both continental and oceanic plate subducts beneath; 2. The continental block engage in the subduction with building orogenic wedge; 3. The new slab develops and two slabs exhibit a deep strike-slip movement (Double circle means pointing out of the screen; Cross inside the circle means pointing into the screen; 4. New slab moves further downward; 5. The old slab breaks off; 6. The new slab subducts beneath.|center]]
