Sun, Y;
Hier-Majumder, S;
Tauzin, B;
Walter, M;
Ballmer, M;
Xu, Y;
Kim, S;
(2021)
Evidence of Volatile-Induced Melting in the Northeast Asian Upper Mantle.
Journal of Geophysical Research: Solid Earth
, 126
(10)
, Article e2021JB022167. 10.1029/2021JB022167.
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Abstract
A seismic low velocity layer (LVL) above the mantle transition zone (MTZ), often thought to be caused by volatile-induced melting, can significantly modulate planetary volatile cycles. In this work, we show that an LVL observed beneath northeast Asia is characterized by small, 0.8 (Formula presented.) 0.5 vol%, average degrees of partial melting. Seismically derived P-T conditions of the LVL indicate that slab-derived (Formula presented.), possibly combined with small amounts of (Formula presented.) O, is necessary to induce melting. Modeling the reactive infiltration instability of the melt in a stationary mantle above a stalled slab, we demonstrate that the volatile-rich melt slowly rises above the stalled slab in the MTZ, with percolation velocities of 200–500 (Formula presented.) m/yr. The melt remains stable within the LVL for this geologically significant period of time, potentially transferring up to 52 Mt/yr of (Formula presented.) from the subducting slab to the mantle for an LVL similar in areal extent ((Formula presented.)) to the northeast Asian LVL. Reaction between the melt channels and the LVL mantle precipitates up to 200 ppmw solid C in localized zones. Using the inferred small melt volume fraction to model trace element abundances and isotopic signatures, we show that interaction between this melt and the surrounding mantle can over the long-term produce rocks bearing a HIMU like geochemical signature.
| Type: | Article |
|---|---|
| Title: | Evidence of Volatile-Induced Melting in the Northeast Asian Upper Mantle |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1029/2021JB022167 |
| Publisher version: | https://doi.org/10.1029/2021JB022167 |
| Language: | English |
| Additional information: | This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
| Keywords: | Carbonate-rich melts, low-velocity layer, northeast Asia, reactive infiltration instability, transition zone, volatile cycle |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Earth Sciences |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10138012 |
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