The oxidation states of niobium and tantalum in mantle melts

Antony D Burnham; Andrew J Berry; Bernard J Wood; Giannantonio Cibin

doi:10.1016/j.chemgeo.2012.09.002

The oxidation states of niobium and tantalum in mantle melts

Antony D Burnham, Andrew J Berry, Bernard J Wood, Giannantonio Cibin

Research output: Contribution to journal › Article (Academic Journal) › peer-review

29 Citations (Scopus)

Abstract

Niobium K-edge and tantalum L_III-edge XANES spectra were recorded for silicate glasses quenched from melts equilibrated at oxygen fugacities (in log units relative to the iron–wüstite buffer) ranging from IW + 6.7 to IW − 4.3 at 1400–1650 °C and atmospheric pressure to 1.5 GPa. Niobium and tantalum were found to occur exclusively as Nb⁵⁺ and Ta⁵⁺. This suggests that changes in oxidation state do not contribute to the fractionation of Nb from Ta in arc settings or the generation of the hidden Nb-rich reservoir that is necessary to explain the deviation of the Nb/Ta ratio of the bulk silicate Earth from the chondritic value.

Original language	English
Pages (from-to)	228-232
Journal	Chemical Geology
Volume	330-331
DOIs	https://doi.org/10.1016/j.chemgeo.2012.09.002
Publication status	Published - 2012

Access to Document

10.1016/j.chemgeo.2012.09.002

Handle.net

Persistent link

Cite this

@article{b49f34c271e640488ca7dd566f1af257,

title = "The oxidation states of niobium and tantalum in mantle melts",

abstract = "Niobium K-edge and tantalum LIII-edge XANES spectra were recorded for silicate glasses quenched from melts equilibrated at oxygen fugacities (in log units relative to the iron–w{\"u}stite buffer) ranging from IW + 6.7 to IW − 4.3 at 1400–1650 °C and atmospheric pressure to 1.5 GPa. Niobium and tantalum were found to occur exclusively as Nb5+ and Ta5+. This suggests that changes in oxidation state do not contribute to the fractionation of Nb from Ta in arc settings or the generation of the hidden Nb-rich reservoir that is necessary to explain the deviation of the Nb/Ta ratio of the bulk silicate Earth from the chondritic value.",

author = "Burnham, {Antony D} and Berry, {Andrew J} and Wood, {Bernard J} and Giannantonio Cibin",

year = "2012",

doi = "10.1016/j.chemgeo.2012.09.002",

language = "English",

volume = "330-331",

pages = "228--232",

journal = "Chemical Geology",

issn = "0009-2541",

publisher = "Elsevier B.V.",

}

TY - JOUR

T1 - The oxidation states of niobium and tantalum in mantle melts

AU - Burnham, Antony D

AU - Berry, Andrew J

AU - Wood, Bernard J

AU - Cibin, Giannantonio

PY - 2012

Y1 - 2012

N2 - Niobium K-edge and tantalum LIII-edge XANES spectra were recorded for silicate glasses quenched from melts equilibrated at oxygen fugacities (in log units relative to the iron–wüstite buffer) ranging from IW + 6.7 to IW − 4.3 at 1400–1650 °C and atmospheric pressure to 1.5 GPa. Niobium and tantalum were found to occur exclusively as Nb5+ and Ta5+. This suggests that changes in oxidation state do not contribute to the fractionation of Nb from Ta in arc settings or the generation of the hidden Nb-rich reservoir that is necessary to explain the deviation of the Nb/Ta ratio of the bulk silicate Earth from the chondritic value.

AB - Niobium K-edge and tantalum LIII-edge XANES spectra were recorded for silicate glasses quenched from melts equilibrated at oxygen fugacities (in log units relative to the iron–wüstite buffer) ranging from IW + 6.7 to IW − 4.3 at 1400–1650 °C and atmospheric pressure to 1.5 GPa. Niobium and tantalum were found to occur exclusively as Nb5+ and Ta5+. This suggests that changes in oxidation state do not contribute to the fractionation of Nb from Ta in arc settings or the generation of the hidden Nb-rich reservoir that is necessary to explain the deviation of the Nb/Ta ratio of the bulk silicate Earth from the chondritic value.

U2 - 10.1016/j.chemgeo.2012.09.002

DO - 10.1016/j.chemgeo.2012.09.002

M3 - Article (Academic Journal)

SN - 0009-2541

VL - 330-331

SP - 228

EP - 232

JO - Chemical Geology

JF - Chemical Geology

ER -

The oxidation states of niobium and tantalum in mantle melts

Abstract

Access to Document

Handle.net

Fingerprint

Cite this