Lu-Hf isotopic evidence of a deep mantle plume source for the ~2.06 Ga Bushveld Large Igneous Province

N. Alex Zirakparvar; E. A. Mathez; H. M. Rajesh; Saebyul Choe

doi:10.1016/j.lithos.2019.105168

Lu-Hf isotopic evidence of a deep mantle plume source for the ~2.06 Ga Bushveld Large Igneous Province

N. Alex Zirakparvar, E. A. Mathez, H. M. Rajesh, Saebyul Choe

Chemical & Isotopic Mass Spectrometry

Research output: Contribution to journal › Article › peer-review

10 Scopus citations

Abstract

The Bushveld Large Igneous Province (B-LIP) comprises a diverse array of >30 magma bodies that intruded the Kaapvaal Craton at ~2.06 Ga. In this paper we use zircon and bulk-rock Lu-Hf isotope data to determine whether the B-LIP formed in response to the arrival of a plume(s) from the deep mantle or by melting of the depleted upper mantle during foundering of an eclogitized residue at the base of the lithosphere. New zircon Hf isotope compositions for four B-LIP bodies yield intrusion-specific average εHf_(2.06Ga) values that range from −20.7 ± 2.8 to −2.7 ± 2.8, largely consistent with literature zircon data for other B-LIP intrusions. Bulk-rock solution εHf_(2.06Ga) values for a variety of B-LIP intrusions range from −2.1 ± 0.2 to −10.6 ± 0.2. Because the most radiogenic Hf isotope compositions across the entire B-LIP are nearly primordial, having an εHf_(2.06Ga) close to 0, it is likely that the heat source of the B-LIP was a plume(s) from deep mantle. The Hf isotope data further suggests that individual intrusions in the B-LIP were produced by melting of three distinct source reservoirs (in addition to melts derived from the plume itself): 1) Subduction and plume modified continental lithospheric mantle; 2) Older (~2.7 Ga) mafic-ultramafic plume-related material trapped in the Kaapvaal lithosphere; and 3) Mid- to upper Kaapvaal crust. The presence of ~2.7 Ga mafic-ultramafic material in the Kaapvaal lithosphere may have acted to strengthen the lithosphere so that it was able to resist being dispersed by the arrival of the B-LIP plume at ~2.06 Ga.

Original language	English
Article number	105168
Journal	Lithos
Volume	348-349
DOIs	https://doi.org/10.1016/j.lithos.2019.105168
State	Published - Dec 1 2019

Funding

This work was funded by an award from the Niarchos Foundation and internal funds from the American Musem of Natural History to E.A. Mathez and N.A. Zirakparvar. Louise Bolge of the LDEO-AMNH ICP-MS laboratory, Brian Monteleone of the WHOI SIMS facility, and Diane Wilford of the WSU Radiogenic Isotope Laboratory are all thanked for their analytical expertise. This manuscript has been authored in part by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ). This work was funded by an award from the Niarchos Foundation and internal funds from the American Musem of Natural History to E.A. Mathez and N.A. Zirakparvar. Louise Bolge of the LDEO-AMNH ICP-MS laboratory, Brian Monteleone of the WHOI SIMS facility, and Diane Wilford of the WSU Radiogenic Isotope Laboratory are all thanked for their analytical expertise. This manuscript has been authored in part by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan).

Funders	Funder number
American Musem of Natural History	DE-AC05-00OR22725
DOE Public Access Plan
Niarchos Foundation
US Department of Energy
WSU Radiogenic Isotope Laboratory
U.S. Department of Energy
American Museum of Natural History
Woods Hole Oceanographic Institution
Stavros Niarchos Foundation

Keywords

Hf isotopes
Large igneous provinces
Subcontinental lithospheric mantle

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1016/j.lithos.2019.105168

Cite this

@article{d04e33ee82f4460d815a24ffea2ee180,

title = "Lu-Hf isotopic evidence of a deep mantle plume source for the ~2.06 Ga Bushveld Large Igneous Province",

abstract = "The Bushveld Large Igneous Province (B-LIP) comprises a diverse array of >30 magma bodies that intruded the Kaapvaal Craton at ~2.06 Ga. In this paper we use zircon and bulk-rock Lu-Hf isotope data to determine whether the B-LIP formed in response to the arrival of a plume(s) from the deep mantle or by melting of the depleted upper mantle during foundering of an eclogitized residue at the base of the lithosphere. New zircon Hf isotope compositions for four B-LIP bodies yield intrusion-specific average εHf(2.06Ga) values that range from −20.7 ± 2.8 to −2.7 ± 2.8, largely consistent with literature zircon data for other B-LIP intrusions. Bulk-rock solution εHf(2.06Ga) values for a variety of B-LIP intrusions range from −2.1 ± 0.2 to −10.6 ± 0.2. Because the most radiogenic Hf isotope compositions across the entire B-LIP are nearly primordial, having an εHf(2.06Ga) close to 0, it is likely that the heat source of the B-LIP was a plume(s) from deep mantle. The Hf isotope data further suggests that individual intrusions in the B-LIP were produced by melting of three distinct source reservoirs (in addition to melts derived from the plume itself): 1) Subduction and plume modified continental lithospheric mantle; 2) Older (~2.7 Ga) mafic-ultramafic plume-related material trapped in the Kaapvaal lithosphere; and 3) Mid- to upper Kaapvaal crust. The presence of ~2.7 Ga mafic-ultramafic material in the Kaapvaal lithosphere may have acted to strengthen the lithosphere so that it was able to resist being dispersed by the arrival of the B-LIP plume at ~2.06 Ga.",

keywords = "Hf isotopes, Large igneous provinces, Subcontinental lithospheric mantle",

author = "Zirakparvar, {N. Alex} and Mathez, {E. A.} and Rajesh, {H. M.} and Saebyul Choe",

note = "Publisher Copyright: {\textcopyright} 2019 Elsevier B.V.",

year = "2019",

month = dec,

day = "1",

doi = "10.1016/j.lithos.2019.105168",

language = "English",

volume = "348-349",

journal = "Lithos",

issn = "0024-4937",

publisher = "Elsevier",

}

TY - JOUR

T1 - Lu-Hf isotopic evidence of a deep mantle plume source for the ~2.06 Ga Bushveld Large Igneous Province

AU - Zirakparvar, N. Alex

AU - Mathez, E. A.

AU - Rajesh, H. M.

AU - Choe, Saebyul

PY - 2019/12/1

Y1 - 2019/12/1

N2 - The Bushveld Large Igneous Province (B-LIP) comprises a diverse array of >30 magma bodies that intruded the Kaapvaal Craton at ~2.06 Ga. In this paper we use zircon and bulk-rock Lu-Hf isotope data to determine whether the B-LIP formed in response to the arrival of a plume(s) from the deep mantle or by melting of the depleted upper mantle during foundering of an eclogitized residue at the base of the lithosphere. New zircon Hf isotope compositions for four B-LIP bodies yield intrusion-specific average εHf(2.06Ga) values that range from −20.7 ± 2.8 to −2.7 ± 2.8, largely consistent with literature zircon data for other B-LIP intrusions. Bulk-rock solution εHf(2.06Ga) values for a variety of B-LIP intrusions range from −2.1 ± 0.2 to −10.6 ± 0.2. Because the most radiogenic Hf isotope compositions across the entire B-LIP are nearly primordial, having an εHf(2.06Ga) close to 0, it is likely that the heat source of the B-LIP was a plume(s) from deep mantle. The Hf isotope data further suggests that individual intrusions in the B-LIP were produced by melting of three distinct source reservoirs (in addition to melts derived from the plume itself): 1) Subduction and plume modified continental lithospheric mantle; 2) Older (~2.7 Ga) mafic-ultramafic plume-related material trapped in the Kaapvaal lithosphere; and 3) Mid- to upper Kaapvaal crust. The presence of ~2.7 Ga mafic-ultramafic material in the Kaapvaal lithosphere may have acted to strengthen the lithosphere so that it was able to resist being dispersed by the arrival of the B-LIP plume at ~2.06 Ga.

AB - The Bushveld Large Igneous Province (B-LIP) comprises a diverse array of >30 magma bodies that intruded the Kaapvaal Craton at ~2.06 Ga. In this paper we use zircon and bulk-rock Lu-Hf isotope data to determine whether the B-LIP formed in response to the arrival of a plume(s) from the deep mantle or by melting of the depleted upper mantle during foundering of an eclogitized residue at the base of the lithosphere. New zircon Hf isotope compositions for four B-LIP bodies yield intrusion-specific average εHf(2.06Ga) values that range from −20.7 ± 2.8 to −2.7 ± 2.8, largely consistent with literature zircon data for other B-LIP intrusions. Bulk-rock solution εHf(2.06Ga) values for a variety of B-LIP intrusions range from −2.1 ± 0.2 to −10.6 ± 0.2. Because the most radiogenic Hf isotope compositions across the entire B-LIP are nearly primordial, having an εHf(2.06Ga) close to 0, it is likely that the heat source of the B-LIP was a plume(s) from deep mantle. The Hf isotope data further suggests that individual intrusions in the B-LIP were produced by melting of three distinct source reservoirs (in addition to melts derived from the plume itself): 1) Subduction and plume modified continental lithospheric mantle; 2) Older (~2.7 Ga) mafic-ultramafic plume-related material trapped in the Kaapvaal lithosphere; and 3) Mid- to upper Kaapvaal crust. The presence of ~2.7 Ga mafic-ultramafic material in the Kaapvaal lithosphere may have acted to strengthen the lithosphere so that it was able to resist being dispersed by the arrival of the B-LIP plume at ~2.06 Ga.

KW - Hf isotopes

KW - Large igneous provinces

KW - Subcontinental lithospheric mantle

UR - http://www.scopus.com/inward/record.url?scp=85071400790&partnerID=8YFLogxK

U2 - 10.1016/j.lithos.2019.105168

DO - 10.1016/j.lithos.2019.105168

M3 - Article

AN - SCOPUS:85071400790

SN - 0024-4937

VL - 348-349

JO - Lithos

JF - Lithos

M1 - 105168

ER -

Lu-Hf isotopic evidence of a deep mantle plume source for the ~2.06 Ga Bushveld Large Igneous Province

Abstract

Funding

Keywords

UN SDGs

Access to Document

Other files and links

Fingerprint

Cite this

Lu-Hf isotopic evidence of a deep mantle plume source for the ~2.06 Ga Bushveld Large Igneous Province

Abstract

Funding

Keywords

UN SDGs

Access to Document

Other files and links

Fingerprint

Cite this

Lu-Hf isotopic evidence of a deep mantle plume source for the ~2.06 Ga Bushveld Large Igneous Province