The formation of new subduction zones is an essential link in the plate tectonic Wilson Cycle as subduction is the only mechanism by which oceans close. Subduction initiation occurs episodically, but relatively frequently: about half of today's subduction zones formed in Cenozoic time. To evolve from the inception of shortening to the formation of a self-sustaining subduction system takes time, however, and is generally estimated to range somewhere between a few to ten million years. This long duration requires that the subduction initiation process be studied from a geological record. Such records include ophiolites and underlying metamorphic soles, but also igneous and sedimentary components of arcs and related basins.

In this session, we invite contributions on 1) structure, petrology, geochemistry, and geochronology of ophiolites and underlying metamorphic soles, or arc and related basin successions that record subduction initiation; 2) geological and geophysical studies on locations where subduction may be initiating today; 3) geophysical modelling studies that aim to understand the dynamics of subduction initiation, subduction polarity reversals, or the possible role of extensional inheritance; 4) kinematic restorations of subduction initiation identifying along which inherited structures subduction may initiate; and 5) differences and similarities between subduction initiation in oceanic and continental realms. We seek a multidisciplinary discussion linking observations and kinematic reconstructions of geological reality to generic physical models of subduction initiation and ophiolite formation.

We are very pleased to announce our invited lectures:
- We will host the Arne Richter Award lecture by João Duarte from the University of Lisbon: "The Future of Earth's Oceans: consequences of subduction invasion in the Atlantic"
- And John Encarnacion from Saint Louis University will present "Geologic constraints on the setting and dynamics of subduction initiation"