The Subduction-Zone Filter and the Impact of Recycled Materials on the Evolution of the Mantle
arc magmatism, chemical recycling, mantle evolution, marine sediment, serpentinite, subduction
Digital Object Identifier (DOI)
The geochemical processes of subduction modulate the recycling of Earth's surface materials into the mantle. Many key trace elements and isotopic tracers are strongly fractionated by subduction, leading to the distinctive chemical signatures of arc lavas and the development of chemically unique, near-surface mantle reservoirs, while other species largely pass through subduction zones back into the deep mantle. Differential recycling of trace elements through subduction processes leads to chemical heterogeneities within the mantle and to profound chemical fractionations between the mantle and crustal rocks.
This article reviews the current understanding of the thermal structures, petrologic makeup, and metamorphic and melting processes within subducting plates. The systematics of volcanic arc lavas, the primary chemical outflux of subduction, and how this outflux and those at shallower depths fractionate the composition of downgoing plates and return mobile species to the surface are examined. The fate of the species that predominantly pass through the subduction filter into the deep mantle and how this may lead over time to the development of chemically distinctive mantle reservoirs are discussed. With constraints from the systematics of two trace elements (boron, which does not pass through the subduction filter, and beryllium, which is largely returned to the deep mantle), an order of recycling efficiency for key trace elements during subduction is proposed.
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Citation / Publisher Attribution
Treatise on Geochemistry (Second Edition), v. 3, p. 479-508
Scholar Commons Citation
Ryan, Jeffrey G. and Chauvel, C., "The Subduction-Zone Filter and the Impact of Recycled Materials on the Evolution of the Mantle" (2013). School of Geosciences Faculty and Staff Publications. 888.