Thin oceanic crust is formed by decompression melting of the upper mantle at mid-ocean ridges, but the origin of the thick and buoyant continental crust is enigmatic. Juvenile continental crust may form from magmas erupted above intraoceanic subduction zones, where oceanic lithosphere subducts beneath other oceanic lithosphere. However, it is unclear why the subduction of dominantly basaltic oc...

Density-driven sinking velocity Density-driven sinking velocity Slab-dip angle Plate-advance velocity Subduction-retreat velocity Subduction-retreat velocity Overriding slab Subducting slab transformations at 400–700 km down. The authors identify four central points. First, subducted material sinks at a velocity that is controlled solely by its negative buoyancy and the viscosity of the surroun...

In order to understand the potential controls on Asian tectonics during the subduction of the Tethys and Indian lithospheres, we reconstruct the coupled subduction-continent deformation history using tomographic imaging, kinematics constraints and numerical modeling. The global P-waves tomographic images of the mantle below the India-Asia collision zone provide constraints on the deep structure...

[1] Oceanic lithosphere undergoes permanent deformation during subduction once the stresses exceed the elastic limit. Departures from elastic behavior occur by brittle failure in the shallow lithosphere and by a combination of lowand high-temperature creep at greater depths. We combine laboratory-based rheological models with estimates of slab shape from earthquake hypocenters to quantify the b...

This review of subduction and geodynamic models is organized around three central questions: (1) Why is subduction asymmetric? (2) Are subducted slabs strong or weak? (3) How do subducted slabs interact with phase transformations, changes in mantle rheology, and possibly chemical boundaries in the mantle? Based on laboratory measurements of the temperature dependence of olivine, one would concl...

The formation and exhumation of high and ultrahigh-pressure, (U)HP, rocks of crustal origin appears to be ubiquitous during Phanerozoic plate subduction and continental collision events. Exhumation of (U)HP material has been shown in some orogens to have occurred only once, during a single short-lived event; in other cases exhumation appears to have occurred multiple discrete times or during a ...

A large amount of water is brought into the Earth’s mantle at subduction zones. Upon subduction, water is released from the subducting slab in a series of metamorphic reactions. The resulting flux into the mantle wedge modifies its chemical and physical properties by mineral hydration with associated weakening, flux melting and changes in the dynamics and thermal structure of subduction zones. ...

The collision of thickened crust with subduction zones significantly modifies subduction. These accretion events lead to net growth of continents and drive much of the subduction-related tectonism. Terrane collision may also have a profound effect on the size, coupling, and rupture characteristics of large intraplate earthquakes. The present accretion of exotic terranes with the Alaska subducti...

[1] The fine-scale seismic structure of the central Mexico subduction zone is studied using moderate-sized (M4-6) intraslab earthquakes. Regional waveforms from the Mapping the Rivera Subduction Zone (MARS) seismic array are complicated and contain detailed information about the subduction zone structure, including evidence of lateral heterogeneity. This waveform information is used to model th...

By enhancing mass transfer and energy release, the cycle of volatiles and melt is a major component of subduction. Investigating this fluid cycle is therefore critical to understand the past and current activity of subduction zones. Fluids can significantly affect rock electrical conductivity and elastic parameters that are measured using electromagnetic and seismic methods, respectively. This ...