Subduction initiation triggered by collision: A review based on examples and models

Ocean-continent subduction cannot be initiated without preceding intra-oceanic subduction!

“…As for the proposed scenario of passive margin collapse, subduction zone transference seems to carry a paradox in view of the temporal geotectonic evolution of the Earth. On the one hand, multiple ribbon-like (micro)-continents were repeatedly drifting away from Gondwana and subsequently accreted to the Eurasian continent with the reestablishment of an active subduction zone at their backside during the evolution of Tethyan systems since the Paleozoic (Yang, 2022). On the other hand, not a single ocean-continent subduction zone was triggered by subduction zone transference in Cenozoic time.…”

“…The archetypal example of such a "failed" subduction zone transference is the collision between India and Eurasia, on-going since ~50 Ma, which did not give rise to a new subduction zone along the southern Indian margin (Van Hinsbergen et al, 2019). Thus, subduction zone transference inferred from Paleozoic plate-tectonic reconstructions is surprisingly frequent (e.g., Torsvik, 2019;Wan et al, 2019), considering the lack of confirmed cases for this mechanism in the Cenozoic, which includes the best preserved geodynamic record (Yang, 2022). This process is also difficult to reproduce in numerical models, which generally show oceanward trench jumping over continued subduction (Tetreault and Buiter, (Zhou et al, 2020).…”

“…As a result, the subducting and overriding plates exchange roles (Stern, 2004) and the initially overlying lithosphere starts to subduct (Figure 1G). Subduction polarity reversal has been demonstrated to be a viable mechanism to explain the possible formation of new subduction zones during the Cenozoic and earlier (see review by Yang (2022) and references therein). The Taiwan and Kamchatka orogens are classic and well-documented examples of the role of this process in the formation of new zones of ocean-continent subduction.…”

“…Subduction is a key element of terrestrial plate tectonics (Stern, 2002). Although the periodic events of opening and closure of oceanic basins (Wilson, 1966) suggest that subduction must initiate frequently in geologic history, the underlying mechanisms that trigger subduction are not fully understood (Stern, 2004;Cloetingh et al, 2021;Yang, 2022). Difficulties in identifying and characterizing subduction initiation in nature are related to poor accessibility of data, lack of a priori knowledge about where subduction begins, incomplete understanding of the geologic, petrologic, and geochemical signatures, as well as the physical parameters required for the emergence of new subduction zones (Gerya, 2011;Stern and Gerya, 2018;Gerya, 2022).…”

Collision‐Induced Subduction Polarity Reversal Explains the Crustal Structure of Northern Borneo: New Results From Virtual Deep Seismic Sounding (VDSS)

“…In the last decade, subduction initiation (SI) has become firmly established as one of the most exciting and rapidly developing fields of modern plate tectonics thanks to improved observations, more realistic geodynamic modeling and more focused laboratory experiments (Stern & Gerya, 2018). Subduction polarity reversal (SPR), a compression‐induced form of SI in which intra‐oceanic subduction is followed by collision, subduction termination, slab break‐off, initiation of subduction of opposite polarity behind the collision zone, orogen collapse and back‐arc spreading driven by roll‐back, has become a particular focus of the geodynamic modeling community in the last few years (e.g., Almeida et al., 2022; Stern & Gerya, 2018; Wang et al., 2022; Yang, 2022). Typical models are 2‐D and involve arc‐continent (Wang et al., 2022) or oceanic plateau‐continent collision (Almeida et al., 2022).…”