DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Origins of ultralow velocity zones through slab-derived metallic melt

Abstract

Understanding the ultralow velocity zones (ULVZs) places constraints on the chemical composition and thermal structure of deep Earth and provides critical information on the dynamics of large-scale mantle convection, but their origin has remained enigmatic for decades. Recent studies suggest that metallic iron and carbon are produced in subducted slabs when they sink beyond a depth of 250 km. Here we show that the eutectic melting curve of the iron-carbon system crosses the current geotherm near Earth’s core-mantle boundary, suggesting that dense metallic melt may form in the lowermost mantle. If concentrated into isolated patches, such melt could produce the seismically observed density and velocity features of ULVZs. Depending on the wetting behavior of the metallic melt, the resultant ULVZs may be short-lived domains that are replenished or regenerated through subduction, or long-lasting regions containing both metallic and silicate melts. Slab-derived metallic melt may produce another type of ULVZ that escapes core sequestration by reacting with the mantle to form iron-rich post-bridgmanite or ferropericlase. The hypotheses connect peculiar features near Earth’s core-mantle boundary to subduction of the oceanic lithosphere through the deep carbon cycle.

Authors:
 [1];  [1]; ORCiD logo [2];  [2]
  1. Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Earth and Environmental Sciences
  2. Carnegie Inst. of Washington, Argonne, IL (United States). Geophysical Lab.
Publication Date:
Research Org.:
Argonne National Laboratory (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
National Science Foundation (NSF); National Aeronautics and Space Administration (NASA)
OSTI Identifier:
1257473
Resource Type:
Accepted Manuscript
Journal Name:
Proceedings of the National Academy of Sciences of the United States of America
Additional Journal Information:
Journal Volume: 113; Journal Issue: 20; Journal ID: ISSN 0027-8424
Publisher:
National Academy of Sciences, Washington, DC (United States)
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES

Citation Formats

Liu, Jiachao, Li, Jie, Hrubiak, Rostislav, and Smith, Jesse S. Origins of ultralow velocity zones through slab-derived metallic melt. United States: N. p., 2016. Web. doi:10.1073/pnas.1519540113.
Liu, Jiachao, Li, Jie, Hrubiak, Rostislav, & Smith, Jesse S. Origins of ultralow velocity zones through slab-derived metallic melt. United States. https://doi.org/10.1073/pnas.1519540113
Liu, Jiachao, Li, Jie, Hrubiak, Rostislav, and Smith, Jesse S. Tue . "Origins of ultralow velocity zones through slab-derived metallic melt". United States. https://doi.org/10.1073/pnas.1519540113. https://www.osti.gov/servlets/purl/1257473.
@article{osti_1257473,
title = {Origins of ultralow velocity zones through slab-derived metallic melt},
author = {Liu, Jiachao and Li, Jie and Hrubiak, Rostislav and Smith, Jesse S.},
abstractNote = {Understanding the ultralow velocity zones (ULVZs) places constraints on the chemical composition and thermal structure of deep Earth and provides critical information on the dynamics of large-scale mantle convection, but their origin has remained enigmatic for decades. Recent studies suggest that metallic iron and carbon are produced in subducted slabs when they sink beyond a depth of 250 km. Here we show that the eutectic melting curve of the iron-carbon system crosses the current geotherm near Earth’s core-mantle boundary, suggesting that dense metallic melt may form in the lowermost mantle. If concentrated into isolated patches, such melt could produce the seismically observed density and velocity features of ULVZs. Depending on the wetting behavior of the metallic melt, the resultant ULVZs may be short-lived domains that are replenished or regenerated through subduction, or long-lasting regions containing both metallic and silicate melts. Slab-derived metallic melt may produce another type of ULVZ that escapes core sequestration by reacting with the mantle to form iron-rich post-bridgmanite or ferropericlase. The hypotheses connect peculiar features near Earth’s core-mantle boundary to subduction of the oceanic lithosphere through the deep carbon cycle.},
doi = {10.1073/pnas.1519540113},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
number = 20,
volume = 113,
place = {United States},
year = {Tue May 03 00:00:00 EDT 2016},
month = {Tue May 03 00:00:00 EDT 2016}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 54 works
Citation information provided by
Web of Science

Save / Share:

Works referenced in this record:

The C-Fe (carbon-iron) system
journal, October 1992


Melting relationships in the Fe–Fe3S system up to the outer core conditions
journal, December 2012

  • Kamada, Seiji; Ohtani, Eiji; Terasaki, Hidenori
  • Earth and Planetary Science Letters, Vol. 359-360
  • DOI: 10.1016/j.epsl.2012.09.038

Diffusion in MgO at high pressures: Constraints on deformation mechanisms and chemical transport at the core-mantle boundary: DIFFUSION IN MgO AT HIGH PRESSURES
journal, January 2003

  • Van Orman, James A.; Fei, Yingwei; Hauri, Erik H.
  • Geophysical Research Letters, Vol. 30, Issue 2
  • DOI: 10.1029/2002GL016343

Characterization and implications of intradecadal variations in length of day
journal, July 2013


Shearing Melt Out of the Earth: An Experimentalist's Perspective on the Influence of Deformation on Melt Extraction
journal, May 2009


New developments in laser-heated diamond anvil cell with in situ synchrotron x-ray diffraction at High Pressure Collaborative Access Team
journal, July 2015

  • Meng, Yue; Hrubiak, Rostislav; Rod, Eric
  • Review of Scientific Instruments, Vol. 86, Issue 7
  • DOI: 10.1063/1.4926895

The oxidation state of the mantle and the extraction of carbon from Earth’s interior
journal, January 2013

  • Stagno, Vincenzo; Ojwang, Dickson O.; McCammon, Catherine A.
  • Nature, Vol. 493, Issue 7430
  • DOI: 10.1038/nature11679

Density of Fe-3.5wt% C liquid at high pressure and temperature and the effect of carbon on the density of the molten iron
journal, November 2013

  • Shimoyama, Yuta; Terasaki, Hidenori; Ohtani, Eiji
  • Physics of the Earth and Planetary Interiors, Vol. 224
  • DOI: 10.1016/j.pepi.2013.08.003

Constraints on magnetic energy and mantle conductivity from the forced nutations of the Earth
journal, January 1992

  • Buffett, Bruce A.
  • Journal of Geophysical Research, Vol. 97, Issue B13
  • DOI: 10.1029/92JB00977

Slab melting as a barrier to deep carbon subduction
journal, January 2016

  • Thomson, Andrew R.; Walter, Michael J.; Kohn, Simon C.
  • Nature, Vol. 529, Issue 7584
  • DOI: 10.1038/nature16174

High-pressure–high-temperature equation of state of KCl and KBr
journal, June 2012


Low Core-Mantle Boundary Temperature Inferred from the Solidus of Pyrolite
journal, January 2014


Iron partitioning in pyrolitic lower mantle
journal, November 2012


Mantle shear–wave tomography and the fate of subducted slabs
journal, September 2002

  • Grand, Steven P.
  • Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences, Vol. 360, Issue 1800
  • DOI: 10.1098/rsta.2002.1077

Melting of Peridotite to 140 Gigapascals
journal, September 2010


A seismologically consistent compositional model of Earth's core
journal, May 2014

  • Badro, J.; Cote, A. S.; Brodholt, J. P.
  • Proceedings of the National Academy of Sciences, Vol. 111, Issue 21
  • DOI: 10.1073/pnas.1316708111

Solidus and liquidus profiles of chondritic mantle: Implication for melting of the Earth across its history
journal, April 2011

  • Andrault, Denis; Bolfan-Casanova, Nathalie; Nigro, Giacomo Lo
  • Earth and Planetary Science Letters, Vol. 304, Issue 1-2
  • DOI: 10.1016/j.epsl.2011.02.006

Fine-scale ultralow-velocity zone structure from high-frequency seismic array data
journal, January 2006

  • Rost, Sebastian; Garnero, Edward J.; Williams, Quentin
  • Journal of Geophysical Research, Vol. 111, Issue B9
  • DOI: 10.1029/2005JB004088

Multi-technique equation of state for Fe 2 SiO 4 melt and the density of Fe-bearing silicate melts from 0 to 161 GPa : EQUATION OF STATE FOR Fe
journal, October 2012

  • Thomas, Claire W.; Liu, Qiong; Agee, Carl B.
  • Journal of Geophysical Research: Solid Earth, Vol. 117, Issue B10
  • DOI: 10.1029/2012JB009403

Seismological constraints on a possible plume root at the core–mantle boundary
journal, June 2005

  • Rost, Sebastian; Garnero, Edward J.; Williams, Quentin
  • Nature, Vol. 435, Issue 7042
  • DOI: 10.1038/nature03620

Melting in the Fe–C system to 70 GPa
journal, June 2009

  • Lord, O. T.; Walter, M. J.; Dasgupta, R.
  • Earth and Planetary Science Letters, Vol. 284, Issue 1-2
  • DOI: 10.1016/j.epsl.2009.04.017

Tracking deep mantle reservoirs with ultra-low velocity zones
journal, October 2010

  • McNamara, Allen K.; Garnero, Edward J.; Rost, Sebastian
  • Earth and Planetary Science Letters, Vol. 299, Issue 1-2
  • DOI: 10.1016/j.epsl.2010.07.042

Experimental evidence for the existence of iron-rich metal in the Earth's lower mantle
journal, March 2004

  • Frost, Daniel J.; Liebske, Christian; Langenhorst, Falko
  • Nature, Vol. 428, Issue 6981
  • DOI: 10.1038/nature02413

Seismic detection of folded, subducted lithosphere at the core–mantle boundary
journal, May 2006

  • Hutko, Alexander R.; Lay, Thorne; Garnero, Edward J.
  • Nature, Vol. 441, Issue 7091
  • DOI: 10.1038/nature04757

Chemical complexity of hotspots caused by cycling oceanic crust through mantle reservoirs
journal, March 2014

  • Li, Mingming; McNamara, Allen K.; Garnero, Edward J.
  • Nature Geoscience, Vol. 7, Issue 5
  • DOI: 10.1038/ngeo2120

Nonstoichiometry and growth of some Fe carbides
text, January 2013

  • Walker, David; Dasgupta, Rajdeep; Li, Jie
  • Columbia University
  • DOI: 10.7916/d8c53wwq

Melting of subducted basalt at the core-mantle boundary
journal, May 2014


Seismic Evidence for Partial Melt at the Base of Earth's Mantle
journal, September 1996


Nonstoichiometry and growth of some Fe carbides
journal, August 2013

  • Walker, D.; Dasgupta, R.; Li, J.
  • Contributions to Mineralogy and Petrology, Vol. 166, Issue 3
  • DOI: 10.1007/s00410-013-0900-7

Mega ultra low velocity zone and mantle flow
journal, February 2013

  • Thorne, Michael S.; Garnero, Edward J.; Jahnke, Gunnar
  • Earth and Planetary Science Letters, Vol. 364
  • DOI: 10.1016/j.epsl.2012.12.034

Iron-Rich Post-Perovskite and the Origin of Ultralow-Velocity Zones
journal, April 2006


Formation of an interconnected network of iron melt at Earth’s lower mantle conditions
journal, October 2013

  • Shi, Crystal Y.; Zhang, Li; Yang, Wenge
  • Nature Geoscience, Vol. 6, Issue 11
  • DOI: 10.1038/ngeo1956

Connectivity of molten Fe alloy in peridotite based on in situ electrical conductivity measurements: implications for core formation in terrestrial planets
journal, May 2004

  • Yoshino, Takashi; Walter, Michael J.; Katsura, Tomoo
  • Earth and Planetary Science Letters, Vol. 222, Issue 2
  • DOI: 10.1016/j.epsl.2004.03.010

Metal saturation in the upper mantle
journal, September 2007

  • Rohrbach, Arno; Ballhaus, Chris; Golla–Schindler, Ute
  • Nature, Vol. 449, Issue 7161
  • DOI: 10.1038/nature06183

Reevaluating carbon fluxes in subduction zones, what goes down, mostly comes up
journal, June 2015

  • Kelemen, Peter B.; Manning, Craig E.
  • Proceedings of the National Academy of Sciences, Vol. 112, Issue 30
  • DOI: 10.1073/pnas.1507889112

Redox freezing and melting in the Earth’s deep mantle resulting from carbon–iron redox coupling
journal, March 2011


The deep carbon cycle and melting in Earth's interior
journal, September 2010


Elastic properties of ferrous bearing MgSiO3 and their relevance to ULVZs
journal, March 2015

  • Muir, Joshua M. R.; Brodholt, John P.
  • Geophysical Journal International, Vol. 201, Issue 1
  • DOI: 10.1093/gji/ggv045

Dynamics and structure of a stirred partially molten ultralow-velocity zone
journal, July 2010


Progressive mixing of meteoritic veneer into the early Earth’s deep mantle
journal, July 2009

  • Maier, Wolfgang D.; Barnes, Stephen J.; Campbell, Ian H.
  • Nature, Vol. 460, Issue 7255
  • DOI: 10.1038/nature08205

Subducted banded iron formations as a source of ultralow-velocity zones at the core–mantle boundary
journal, March 2005


Is there a thin electrically conducting layer at the base of the mantle?
book, January 1998

  • Poirier, J. P.; Malavergne, V.; Le Mouël, J. L.
  • The Core‐Mantle Boundary Region
  • DOI: 10.1029/GD028p0131

Suction mechanism for iron entrainment into the lower mantle
journal, January 2006

  • Kanda, Ravi V. S.; Stevenson, David J.
  • Geophysical Research Letters, Vol. 33, Issue 2
  • DOI: 10.1029/2005GL025009

Solubilities of O and Si in liquid iron in equilibrium with (Mg,Fe)SiO 3 perovskite and the light elements in the core
journal, January 2005


Experimental study and thermodynamic calculations of phase relations in the Fe–C system at high pressure
journal, December 2014


Silicon self-diffusion in MgSiO3 perovskite at 25 GPa
journal, May 2000

  • Yamazaki, Daisuke; Kato, Takumi; Yurimoto, Hisayoshi
  • Physics of the Earth and Planetary Interiors, Vol. 119, Issue 3-4
  • DOI: 10.1016/S0031-9201(00)00135-7

Quasihydrostatic Equation of State of Iron above 2 Mbar
journal, November 2006


Partial melting in a thermo-chemical boundary layer at the base of the mantle
journal, September 2004

  • Lay, Thorne; Garnero, Edward J.; Williams, Quentin
  • Physics of the Earth and Planetary Interiors, Vol. 146, Issue 3-4
  • DOI: 10.1016/j.pepi.2004.04.004

Earth's Core-Mantle Boundary: Results of Experiments at High Pressures and Temperatures
journal, March 1991


Preliminary reference Earth model
journal, June 1981


Melting of Iron at Earth's Inner Core Boundary Based on Fast X-ray Diffraction
journal, April 2013


Elastic properties of ferropericlase at lower mantle conditions and its relevance to ULVZs
journal, May 2015


Carbon in the core
journal, June 1993


Two-dimensional detector software: From real detector to idealised image or two-theta scan
journal, January 1996

  • Hammersley, A. P.; Svensson, S. O.; Hanfland, M.
  • High Pressure Research, Vol. 14, Issue 4-6, p. 235-248
  • DOI: 10.1080/08957959608201408

Spin crossover and iron-rich silicate melt in the Earth’s deep mantle
journal, April 2011

  • Nomura, Ryuichi; Ozawa, Haruka; Tateno, Shigehiko
  • Nature, Vol. 473, Issue 7346
  • DOI: 10.1038/nature09940

Very low sound velocities in iron-rich (Mg,Fe)O: Implications for the core-mantle boundary region: SOUND VELOCITIES OF IRON-RICH (Mg,Fe)O
journal, August 2010

  • Wicks, J. K.; Jackson, J. M.; Sturhahn, W.
  • Geophysical Research Letters, Vol. 37, Issue 15
  • DOI: 10.1029/2010GL043689

Works referencing / citing this record:

Effect of observed micropolar motions on wave propagation in deep Earth minerals
journal, March 2018

  • Abreu, Rafael; Thomas, Christine; Durand, Stephanie
  • Physics of the Earth and Planetary Interiors, Vol. 276
  • DOI: 10.1016/j.pepi.2017.04.006

Nitrogen Content in the Earth's Outer Core
journal, January 2019

  • Bajgain, Suraj K.; Mookherjee, Mainak; Dasgupta, Rajdeep
  • Geophysical Research Letters, Vol. 46, Issue 1
  • DOI: 10.1029/2018gl080555

Carbon-bearing silicate melt at deep mantle conditions
journal, April 2017


On the Melting of Defective FCC Interstitial Alloy γ-FeC under Pressure up to 100 GPa
journal, November 2019

  • Hoc, Nguyen-Quang; Viet, Le-Hong; Dung, Nguyen-Trong
  • Journal of Electronic Materials, Vol. 49, Issue 2
  • DOI: 10.1007/s11664-019-07829-9

High-Pressure Sound Velocity Measurements of Liquids Using In Situ Ultrasonic Techniques in a Multianvil Apparatus
journal, January 2020


Compositionally-distinct ultra-low velocity zones on Earth’s core-mantle boundary
journal, August 2017


Evaluating the Role of Iron-Rich (Mg,Fe)O in Ultralow Velocity Zones
journal, December 2019

  • Dobrosavljevic, Vasilije V.; Sturhahn, Wolfgang; Jackson, Jennifer M.
  • Minerals, Vol. 9, Issue 12
  • DOI: 10.3390/min9120762

Large gem diamonds from metallic liquid in Earth’s deep mantle
journal, December 2016