Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5784330 | Lithos | 2017 | 27 Pages |
Abstract
At low temperatures and relatively dry conditions, reactions are delayed due to the sluggish kinetics, so that non-equilibrium phase aggregates can persist metastably beyond the equilibrium phase boundary. Survival of low-density metastable olivine, Ringwoodite, pyroxene and pyrope garnet in the transition zone and uppermost lower mantle produces positive buoyancy forces that decrease the subduction velocity and may lead to slab stagnation in the transition zone. The presence of deep metastable portions is still debated, and should not be associated a-priori with a completely dry slab as field observations suggest that heterogeneously hydrated oceanic plates could contain metastable dry portions surrounded by transformed wet rocks.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Geochemistry and Petrology
Authors
Manuele Faccenda, Luca Dal Zilio,