Source depletion and extent of melting in the Tongan sub-arc mantle

J. T. Caulfield; S. P. Turner; A. Dosseto; N. J. Pearson; C. Beier

doi:10.1016/j.epsl.2008.06.040

Source depletion and extent of melting in the Tongan sub-arc mantle

J. T. Caulfield^*, S. P. Turner, A. Dosseto, N. J. Pearson, C. Beier

^*Corresponding author for this work

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

47 Citations (Scopus)

Abstract

The fluid immobile High Field Strength Elements (HFSE) Nb and Ta can be used to distinguish between the effects of variable extents of melting and prior source depletion of the Tongan sub-arc mantle. Melting of spinel Iherzolite beneath the Lau Basin back-arc spreading centres has the ability to fractionate Nb from Ta due to the greater compatibility of the latter in clinopyroxene. The identified spatial variation in plate velocities and separation of melt extraction zones, combined with extremely depleted lavas make Tonga an ideal setting in which to test models for arc melt generation and the role of back-arc magmatism. We present new data acquired by laser ablation-ICPMS of fused sample glasses produced without the use of a melt fluxing agent. The results show an arc trend towards strongly sub-chondritic Nb/Ta (

Original language	English
Pages (from-to)	279-288
Number of pages	10
Journal	Earth and Planetary Science Letters
Volume	273
Issue number	3-4
DOIs	https://doi.org/10.1016/j.epsl.2008.06.040
Publication status	Published - 15 Sept 2008

Keywords

HFSE
depletion
sub-arc
back-arc
hydrous
melting
HIGH-FIELD STRENGTH
ISLAND-ARC
LAU BASIN
SUBDUCTION ZONES
GEOLOGICAL-MATERIALS
ELEMENT COMPOSITION
VOLCANIC-ROCKS
HIGH-PRESSURE
FLOW BENEATH
1.5 GPA

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10.1016/j.epsl.2008.06.040

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title = "Source depletion and extent of melting in the Tongan sub-arc mantle",

abstract = "The fluid immobile High Field Strength Elements (HFSE) Nb and Ta can be used to distinguish between the effects of variable extents of melting and prior source depletion of the Tongan sub-arc mantle. Melting of spinel Iherzolite beneath the Lau Basin back-arc spreading centres has the ability to fractionate Nb from Ta due to the greater compatibility of the latter in clinopyroxene. The identified spatial variation in plate velocities and separation of melt extraction zones, combined with extremely depleted lavas make Tonga an ideal setting in which to test models for arc melt generation and the role of back-arc magmatism. We present new data acquired by laser ablation-ICPMS of fused sample glasses produced without the use of a melt fluxing agent. The results show an arc trend towards strongly sub-chondritic Nb/Ta (",

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author = "Caulfield, {J. T.} and Turner, {S. P.} and A. Dosseto and Pearson, {N. J.} and C. Beier",

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T1 - Source depletion and extent of melting in the Tongan sub-arc mantle

AU - Caulfield, J. T.

AU - Turner, S. P.

AU - Dosseto, A.

AU - Pearson, N. J.

AU - Beier, C.

PY - 2008/9/15

Y1 - 2008/9/15

N2 - The fluid immobile High Field Strength Elements (HFSE) Nb and Ta can be used to distinguish between the effects of variable extents of melting and prior source depletion of the Tongan sub-arc mantle. Melting of spinel Iherzolite beneath the Lau Basin back-arc spreading centres has the ability to fractionate Nb from Ta due to the greater compatibility of the latter in clinopyroxene. The identified spatial variation in plate velocities and separation of melt extraction zones, combined with extremely depleted lavas make Tonga an ideal setting in which to test models for arc melt generation and the role of back-arc magmatism. We present new data acquired by laser ablation-ICPMS of fused sample glasses produced without the use of a melt fluxing agent. The results show an arc trend towards strongly sub-chondritic Nb/Ta (

AB - The fluid immobile High Field Strength Elements (HFSE) Nb and Ta can be used to distinguish between the effects of variable extents of melting and prior source depletion of the Tongan sub-arc mantle. Melting of spinel Iherzolite beneath the Lau Basin back-arc spreading centres has the ability to fractionate Nb from Ta due to the greater compatibility of the latter in clinopyroxene. The identified spatial variation in plate velocities and separation of melt extraction zones, combined with extremely depleted lavas make Tonga an ideal setting in which to test models for arc melt generation and the role of back-arc magmatism. We present new data acquired by laser ablation-ICPMS of fused sample glasses produced without the use of a melt fluxing agent. The results show an arc trend towards strongly sub-chondritic Nb/Ta (

KW - HFSE

KW - depletion

KW - sub-arc

KW - back-arc

KW - hydrous

KW - melting

KW - HIGH-FIELD STRENGTH

KW - ISLAND-ARC

KW - LAU BASIN

KW - SUBDUCTION ZONES

KW - GEOLOGICAL-MATERIALS

KW - ELEMENT COMPOSITION

KW - VOLCANIC-ROCKS

KW - HIGH-PRESSURE

KW - FLOW BENEATH

KW - 1.5 GPA

U2 - 10.1016/j.epsl.2008.06.040

DO - 10.1016/j.epsl.2008.06.040

M3 - Article

SN - 0012-821X

VL - 273

SP - 279

EP - 288

JO - Earth and Planetary Science Letters

JF - Earth and Planetary Science Letters

IS - 3-4

ER -

Source depletion and extent of melting in the Tongan sub-arc mantle

Abstract

Keywords

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