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The models of slab-break up and double convergence are based on observations by geologists, and the lithosphere break-up model is based on experimental [[simulation]].
The criteria for having subduction polarity reversal are▼
# Intra-oceanic subduction system with a buoyant continental plate▼
# Subduction system ceases with the involvement of continental plate▼
# Old slab breaks off<ref name=":113" /><ref name=":132222" />▼
Different models representing the subduction polarity reversal depends highly on parameters the Geologists considered. Here is the summary table showing the comparison models.▼
{| class="wikitable"▼
|'''Difference'''▼
!Slab break-off▼
!Double convergence▼
!Lithospheric break-up▼
|-▼
|'''Reasons of slab break-off'''▼
|Tensile force at the old slab▼
|Lateral sliding by the new slab▼
|Pre-existing fault leads to penetration of new slab▼
|-▼
|'''Accommodation of new slab'''▼
|Mantle window▼
|A deep strike-slip movement▼
|Penetration of new slab breaks of the old slab▼
|}▼
=== Slab break-off ===
This model was developed by analyzing the geological cross section along the collision between [[Eurasian Plate|Eurasian plate]] and the [[Philippine Sea Plate|Philippine sea plate]], which is the ___location of an ongoing flipping of subduction polarity.<ref name=":132222" />
When two [[Oceanic crust|oceanic plates]] migrate towards each other, one plate overrides another forming a [[Subduction|subduction system]]. Later, a light and buoyant [[Continental margin|passive continental margin]] introduced into this system will cause the cessation of [[Subduction|subduction system]].<ref name=":132222" /> On one hand, the buoyant plate resists subduction beneath the overriding plate.<ref name=":132222" /> On the other hand, the dense oceanic [[Slab (geology)|slab]] at the subducting plate prefers to move downward.<ref name=":132222" /> These opposite forces will generate a [[Tension (physics)|tensile force]] or gravitational instability on the downward [[slab]] and lead to the break-off of the slab.<ref name=":822">{{Cite book|url=https://books.google.com/books?hl=en&lr=&id=7l9KrXgOELwC&oi=fnd&pg=PR9&dq=subduction:+Insights+from+Physical+Mod-+eling.+Kluwer,+Dordrecht&ots=CrVyim6ABr&sig=5Oe0Gge72kTdliFQ6md_m065c9I&redir_esc=y#v=onepage&q=subduction:%20Insights%20from%20Physical%20Mod-%20eling.%20Kluwer,%20Dordrecht&f=false|title=Subduction: Insights from Physical Modeling|last=Shemenda|first=Alexander I.|date=1994-09-30|publisher=Springer Science & Business Media|isbn=9780792330424|language=en}}</ref> The space where the break-off slab separates will form a mantle window.<ref name=":132222" /> Subsequently, the less dense continental margin forms the overriding plate, while the oceanic plate becomes the subducting slab.<ref name=":132222" /> The direction of subduction system changes since the break-off of slab creates the space, which is the major parameter of this model.<ref name=":132222" />
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The initial setting of the simulated [[Subduction|subduction zone]] model is confined by two pistons. The piston connected to the overriding plate is locked, while the piston linking to subducting plate is subjected to a constant rate of compression.<ref name=":113" /> More importantly, there is a relatively thin [[Volcanic arc|magmatic arc]] and pre-existing fault dipping towards the subducting plate at the overriding plate.<ref name=":113" /> The detachment of the pre-existing fault occurs when buoyant [[continental margin]] is in contact with the overriding plate.<ref name=":113" /> It is because the buoyant margin resists [[subduction]] and significantly increases the [[Friction|frictional force]] in the contact region.<ref name=":113" /> The subduction then stops. Subsequently, the new subducting slab develops at an overriding plate with the continuous compression.<ref name=":113" /> The new developing slab eventually penetrates and breaks the old slab.<ref name=":113" /> A new subduction is developed with an opposite direction of the previous one.<ref name=":113" />
In reality, the magmatic arc is a relatively weak zone at the overriding plate because it has a thin lithosphere and is further weakened by high heat flow<ref>{{Cite journal|last=Currie|first=Claire A.|last2=Hyndman|first2=Roy D.|date=2006-08-01|title=The thermal structure of subduction zone back arcs|url=http://onlinelibrary.wiley.com/doi/10.1029/2005JB004024/abstract|journal=Journal of Geophysical Research: Solid Earth|language=en|volume=111|issue=B8|pages=B08404|doi=10.1029/2005JB004024|issn=2156-2202}}</ref><ref>{{Cite journal|last=Currie|first=C. A|last2=Wang|first2=K|last3=Hyndman|first3=Roy D|last4=He|first4=Jiangheng|date=2004-06-30|title=The thermal effects of steady-state slab-driven mantle flow above a subducting plate: the Cascadia subduction zone and backarc|url=http://www.sciencedirect.com/science/article/pii/S0012821X04002687|journal=Earth and Planetary Science Letters|volume=223|issue=1–2|pages=35–48|doi=10.1016/j.epsl.2004.04.020}}</ref> and hot fluid.<ref>{{Cite journal|last=Arcay|first=D.|last2=Doin|first2=M.-P.|last3=Tric|first3=E.|last4=Bousquet|first4=R.|last5=de Capitani|first5=C.|date=2006-02-01|title=Overriding plate thinning in subduction zones: Localized convection induced by slab dehydration|url=http://onlinelibrary.wiley.com/doi/10.1029/2005GC001061/abstract|journal=Geochemistry, Geophysics, Geosystems|language=en|volume=7|issue=2|pages=Q02007|doi=10.1029/2005GC001061|issn=1525-2027}}</ref><ref>{{Cite journal|last=Honda|first=Satoru|last2=Yoshida|first2=Takeyoshi|date=2005-01-01|title=Application of the model of small-scale convection under the island arc to the NE Honshu subduction zone|url=http://onlinelibrary.wiley.com/doi/10.1029/2004GC000785/abstract|journal=Geochemistry, Geophysics, Geosystems|language=en|volume=6|issue=1|pages=Q01002|doi=10.1029/2004GC000785|issn=1525-2027}}</ref> Pre-existing faults in this simulation are also common in the magmatic arc.<ref>{{Cite journal|last=Toth|first=John|last2=Gurnis|first2=Michael|date=1998-08-10|title=Dynamics of subduction initiation at preexisting fault zones|url=http://onlinelibrary.wiley.com/doi/10.1029/98JB01076/abstract|journal=Journal of Geophysical Research: Solid Earth|language=en|volume=103|issue=B8|pages=18053–18067|doi=10.1029/98JB01076|issn=2156-2202}}</ref> This experiment is a successful analogy to subduction polarity reversal happening at Kamchatka in early Eocene<ref name=":54" /><ref>{{Cite journal|last=Konstantinovskaia|first=Elena A|date=2000-10-15|title=Geodynamics of an Early Eocene arc–continent collision reconstructed from the Kamchatka Orogenic Belt, NE Russia|url=http://www.sciencedirect.com/science/article/pii/S0040195100001323|journal=Tectonophysics|volume=325|issue=1–2|pages=87–105|doi=10.1016/S0040-1951(00)00132-3}}</ref> and the active example at Taiwan region<ref name=":113" /><ref name=":03" /> as well as at Timor.<ref>Silver, E. A., Reed, D., McCaffrey, R., & Joyodiwiryo, Y. (1983). Back arc thrusting in the eastern Sunda arc, Indonesia- A consequence of arc-continent collision. ''Journal of Geophysical Research'', ''88''(B9), 7429-7448.</ref><ref>{{Cite journal|last=Snyder|first=D. B.|last2=Prasetyo|first2=H.|last3=Blundell|first3=D. J.|last4=Pigram|first4=C. J.|last5=Barber|first5=A. J.|last6=Richardson|first6=A.|last7=Tjokosaproetro|first7=S.|date=1996-02-01|title=A dual doubly vergent orogen in the Banda Arc continent-arc collision zone as observed on deep seismic reflection profiles|url=http://onlinelibrary.wiley.com/doi/10.1029/95TC02352/abstract|journal=Tectonics|language=en|volume=15|issue=1|pages=34–53|doi=10.1029/95TC02352|issn=1944-9194}}</ref>
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▲The criteria for having subduction polarity reversal are
▲# Intra-oceanic subduction system with a buoyant continental plate
▲# Subduction system ceases with the involvement of continental plate
▲# Old slab breaks off<ref name=":113" /><ref name=":132222" />
▲Different models representing the subduction polarity reversal depends highly on parameters the Geologists considered. Here is the summary table showing the comparison models.
▲{| class="wikitable"
▲|'''Difference'''
▲!Slab break-off
▲!Double convergence
▲!Lithospheric break-up
▲|-
▲|'''Reasons of slab break-off'''
▲|Tensile force at the old slab
▲|Lateral sliding by the new slab
▲|Pre-existing fault leads to penetration of new slab
▲|-
▲|'''Accommodation of new slab'''
▲|Mantle window
▲|A deep strike-slip movement
▲|Penetration of new slab breaks of the old slab
|}
| |||