Survival of LLSVPs for billions of years in a vigorously convecting mantle: Replenishment and destruction of chemical anomaly

Elvira Mulyukova; Bernhard Steinberger; Marcin Dąbrowski; Stephan V. Sobolev

doi:10.1002/2014jb011688

journal article May 01, 2015

Survival of LLSVPs for billions of years in a vigorously convecting mantle: Replenishment and destruction of chemical anomaly

Elvira Mulyukova Bernhard Steinberger

Marcin Dąbrowski Stephan V. Sobolev

Journal of Geophysical Research: Solid Earth Vol. 120 No. 5 pp. 3824-3847 · American Geophysical Union (AGU)

View at Publisher Save 10.1002/2014jb011688

Abstract

AbstractWe study segregation of the subducted oceanic crust (OC) at the core‐mantle boundary and its ability to accumulate and form large thermochemical piles (such as the seismically observed Large Low Shear Velocity Provinces (LLSVPs)). Our high‐resolution numerical simulations of thermochemical mantle convection suggest that the longevity of LLSVPs for up to three billion years, and possibly longer, can be ensured by a balance in the rate of segregation of high‐density OC material to the core‐mantle boundary (CMB) and the rate of its entrainment away from the CMB by mantle upwellings. For a range of parameters tested in this study, a large‐scale compositional anomaly forms at the CMB, similar in shape and size to the LLSVPs. Neutrally buoyant thermochemical piles formed by mechanical stirring—where thermally induced negative density anomaly is balanced by the presence of a fraction of dense anomalous material—best resemble the geometry of LLSVPs. Such neutrally buoyant piles tend to emerge and survive for at least 3 Gyr in simulations with quite different parameters. We conclude that for a plausible range of values of density anomaly of OC material in the lower mantle—it is likely that it segregates to the CMB, gets mechanically mixed with the ambient material, and forms neutrally buoyant large‐scale compositional anomalies similar in shape to the LLSVPs.

Topics

No keywords indexed for this article. Browse by subject →

References

99

[1]

10.1111/j.1365-246x.2006.03172.x

[2]

10.1017/s0022112092004580

[3]

10.1111/j.1365-246x.1989.tb05511.x

[4]

10.1029/2012gc004267

[5]

Deep storage of oceanic crust in a vigorously convecting mantle

J. P. Brandenburg, P. E. van Keken

Journal of Geophysical Research: Oceans 10.1029/2006jb004813

[6]

10.1029/2001gl014649

[7]

10.1016/j.epsl.2007.09.042

[8]

10.1016/0012-821x(83)90060-2

[9]

10.1111/j.1365-246x.1984.tb01939.x

[10]

10.1016/0012-821x(89)90112-x

[11]

Christensen U. "Segregation of subducted oceanic crust in the convecting mantle" J. Geophys. Res. (1994)

[12]

10.1029/2007gc001719

[13]

10.1038/45461

[14]

10.1016/s0012-821x(02)00897-x

[15]

10.1016/s0016-7037(02)00915-8

[16]

10.1111/j.1365-246x.2010.04637.x

[17]

10.1016/j.epsl.2012.07.012

[18]

10.1016/j.pepi.2008.06.023

[19]

10.1029/2011gc003567

[20]

10.1016/0031-9201(81)90046-7

[21]

10.1016/j.epsl.2010.08.013

[22]

Structure and Dynamics of Earth's Lower Mantle

Edward J. Garnero, Allen K. McNamara

Science 10.1126/science.1148028

[23]

10.1016/j.pepi.2003.09.006

[24]

10.1016/j.epsl.2004.07.021

[25]

10.1029/jb091ib11p11407

[26]

10.1029/jb091ib06p06375

[27]

10.1029/gl013i006p00541

[28]

10.1016/s0012-821x(00)00009-1

[29]

10.1038/nature06380

[30]

10.1029/2008jb005814

[31]

10.1016/j.epsl.2007.10.042

[32]

10.1016/j.pepi.2008.07.037

[33]

Phase transition and density of subducted MORB crust in the lower mantle

Kei Hirose, Naoto Takafuji, Nagayoshi Sata et al.

Earth and Planetary Science Letters 10.1016/j.epsl.2005.06.035

[34]

10.1016/0012-821x(82)90161-3

[35]

10.1016/j.pepi.2008.04.007

[36]

10.1029/2007gc001621

[37]

10.1126/science.285.5431.1231

[38]

10.1029/92jb02117

[39]

Jaupart C. (2007) 10.1016/b978-044452748-6.00114-0

[40]

10.1007/s000240050130

[41]

10.1017/cbo9780511804892

[42]

10.1126/science.260.5109.771

[43]

10.1126/science.270.5235.458

[44]

10.1029/jb095ib01p00421

[45]

10.1126/science.283.5409.1881

[46]

10.1016/j.chemgeo.2004.08.050

[47]

Krotkiewski M.(2013) MUTILS—A set of efficient modeling tools for multi‐core CPUs implemented in MEX. Abstracts EGU2013‐7877 paper presented at EGU General Assembly Conference 2013 Vienna 7–12 April.

[48]

10.1016/j.epsl.2006.11.029

[49]

A crystallizing dense magma ocean at the base of the Earth’s mantle

S. Labrosse, J. W. Hernlund, N. Coltice

Nature 10.1038/nature06355

[50]

10.1038/ngeo.2007.44

Showing 50 of 99 references

Cited By

86

Role of the Kerguelen mantle plume in breakup of eastern Gondwana: Evidence from early cretaceous volcanic rocks in the eastern Tethyan Himalaya

Wenxiao Peng, Tianshui Yang · 2022

Palaeogeography, Palaeoclimatology,...

Metrics

86

Citations

99

References

Details

Published: May 01, 2015
Vol/Issue: 120(5)
Pages: 3824-3847
License: View

Authors

E

Elvira Mulyukova

Physics of the Earth GFZ German Research Center for Geosciences Potsdam Germany

B

Bernhard Steinberger

Physics of the Earth GFZ German Research Center for Geosciences Potsdam Germany; Centre for Earth Evolution and Dynamics University of Oslo Oslo Norway

M

Marcin Dąbrowski

Computational Geology Laboratory Polish Geological Institute‐National Research Institute Wroclaw Poland; Physics of Geological Processes University of Oslo Oslo Norway

S

Stephan V. Sobolev

Physics of the Earth GFZ German Research Center for Geosciences Potsdam Germany; Institute of Earth and Environmental Science University of Potsdam Potsdam Germany

Funding

Helmholtz Association

Freie Universitat Berlin and Universitat Potsdam

Cite This Article

Elvira Mulyukova, Bernhard Steinberger, Marcin Dąbrowski, et al. (2015). Survival of LLSVPs for billions of years in a vigorously convecting mantle: Replenishment and destruction of chemical anomaly. Journal of Geophysical Research: Solid Earth, 120(5), 3824-3847. https://doi.org/10.1002/2014jb011688

Survival of LLSVPs for billions of years in a vigorously convecting mantle: Replenishment and destruction of chemical anomaly

You May Also Like