Concentrations of hydrogen, major, minor, trace and ultra-trace elements in natural olivines

Sylvie Demouchy, Olivier Alard

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Taking advantages of recent analytical advances, we investigate the potential coupled H and trace element incorporations in 17 olivine crystals from ten different localities. Olivine specimens were prepared as prismatic sections, and their major (micro X-ray fluorescence) and minor, trace, and ultra-trace element concentrations (laser ablation inductively coupled plasma mass spectrometry) were determined. Hydrogen concentrations were quantified using both unpolarized and polarized Fourier transform infrared spectroscopy (FTIR). Forsterite contents (= 100 × (Mg/Fe+Mg)) range from 83.2 to 94.1%, in agreement with the geological diversity of the crystals. Hydrogen concentrations range from 0 (dry) to 54 ppm H2O wt and are homogenous per crystal (except for one sample in which the H heterogeneity does not correlate to minor or trace element distributions). Total minor element concentrations range from 3487 to 6493 ppm, and are dominated by Ni, Mn, and Ca or B. Total rare earth element and extended trace element concentrations are very low (<1 ppm). Magmatic olivine (La Réunion, France) and hydrothermal olivine from a metamorphic setting (Norway) show the most and least atomic impurities, respectively, and mantle-derived olivines have concentrations between these two extremes. Combined with minor, trace, and ultra-trace element concentrations, the hydrogen concentrations and OH bands observed by FTIR reflect the geological diversity. Hydrogen concentrations are inversely correlated with di-, tri-, tetra-, and pentavalent impurities, indicating their competition for metal vacancies. However, we observe a broad positive correlation between OH bands at 3575 and 3525 cm-1 and Ti concentration, confirming the existence of a titanium clinohumite-like point defect. Nonetheless, Ti impurities do not exclusively control hydrogen incorporation in olivine due to the co-existence of other atomic impurities. Our results demonstrate that hydrogen behaves as an incompatible and opportunist element in olivine.
LanguageEnglish
Article numberGCA-S-19-01169
JournalGeochimica et Cosmochimica Acta
Publication statusSubmitted - 18 Sep 2019

Fingerprint

Trace Elements
Hydrogen
olivine
trace element
hydrogen
Impurities
crystal
FTIR spectroscopy
Crystals
clinohumite
Inductively coupled plasma mass spectrometry
forsterite
Laser ablation
Point defects
Titanium
Rare earth elements
X-ray fluorescence
ablation
titanium
coexistence

Bibliographical note

Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.

Keywords

  • MANTLE
  • Peridotite
  • Olivine
  • Hydrogen
  • TRACE-ELEMENTS
  • FTIR analysis
  • LA-ICP-MS
  • Volatile Elements in Differentiated Planetary Interiors

Cite this

@article{9de4b7e92aeb419aa450289099b58d5d,
title = "Concentrations of hydrogen, major, minor, trace and ultra-trace elements in natural olivines",
abstract = "Taking advantages of recent analytical advances, we investigate the potential coupled H and trace element incorporations in 17 olivine crystals from ten different localities. Olivine specimens were prepared as prismatic sections, and their major (micro X-ray fluorescence) and minor, trace, and ultra-trace element concentrations (laser ablation inductively coupled plasma mass spectrometry) were determined. Hydrogen concentrations were quantified using both unpolarized and polarized Fourier transform infrared spectroscopy (FTIR). Forsterite contents (= 100 × (Mg/Fe+Mg)) range from 83.2 to 94.1{\%}, in agreement with the geological diversity of the crystals. Hydrogen concentrations range from 0 (dry) to 54 ppm H2O wt and are homogenous per crystal (except for one sample in which the H heterogeneity does not correlate to minor or trace element distributions). Total minor element concentrations range from 3487 to 6493 ppm, and are dominated by Ni, Mn, and Ca or B. Total rare earth element and extended trace element concentrations are very low (<1 ppm). Magmatic olivine (La Réunion, France) and hydrothermal olivine from a metamorphic setting (Norway) show the most and least atomic impurities, respectively, and mantle-derived olivines have concentrations between these two extremes. Combined with minor, trace, and ultra-trace element concentrations, the hydrogen concentrations and OH bands observed by FTIR reflect the geological diversity. Hydrogen concentrations are inversely correlated with di-, tri-, tetra-, and pentavalent impurities, indicating their competition for metal vacancies. However, we observe a broad positive correlation between OH bands at 3575 and 3525 cm-1 and Ti concentration, confirming the existence of a titanium clinohumite-like point defect. Nonetheless, Ti impurities do not exclusively control hydrogen incorporation in olivine due to the co-existence of other atomic impurities. Our results demonstrate that hydrogen behaves as an incompatible and opportunist element in olivine.",
keywords = "MANTLE, Peridotite, Olivine, Hydrogen, TRACE-ELEMENTS, FTIR analysis, LA-ICP-MS, Volatile Elements in Differentiated Planetary Interiors",
author = "Sylvie Demouchy and Olivier Alard",
note = "Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.",
year = "2019",
month = "9",
day = "18",
language = "English",
journal = "Geochimica et Cosmochimica Acta",
issn = "0016-7037",
publisher = "Pergamon-Elsevier Science",

}

Concentrations of hydrogen, major, minor, trace and ultra-trace elements in natural olivines. / Demouchy, Sylvie; Alard, Olivier.

In: Geochimica et Cosmochimica Acta, 18.09.2019.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Concentrations of hydrogen, major, minor, trace and ultra-trace elements in natural olivines

AU - Demouchy, Sylvie

AU - Alard, Olivier

N1 - Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.

PY - 2019/9/18

Y1 - 2019/9/18

N2 - Taking advantages of recent analytical advances, we investigate the potential coupled H and trace element incorporations in 17 olivine crystals from ten different localities. Olivine specimens were prepared as prismatic sections, and their major (micro X-ray fluorescence) and minor, trace, and ultra-trace element concentrations (laser ablation inductively coupled plasma mass spectrometry) were determined. Hydrogen concentrations were quantified using both unpolarized and polarized Fourier transform infrared spectroscopy (FTIR). Forsterite contents (= 100 × (Mg/Fe+Mg)) range from 83.2 to 94.1%, in agreement with the geological diversity of the crystals. Hydrogen concentrations range from 0 (dry) to 54 ppm H2O wt and are homogenous per crystal (except for one sample in which the H heterogeneity does not correlate to minor or trace element distributions). Total minor element concentrations range from 3487 to 6493 ppm, and are dominated by Ni, Mn, and Ca or B. Total rare earth element and extended trace element concentrations are very low (<1 ppm). Magmatic olivine (La Réunion, France) and hydrothermal olivine from a metamorphic setting (Norway) show the most and least atomic impurities, respectively, and mantle-derived olivines have concentrations between these two extremes. Combined with minor, trace, and ultra-trace element concentrations, the hydrogen concentrations and OH bands observed by FTIR reflect the geological diversity. Hydrogen concentrations are inversely correlated with di-, tri-, tetra-, and pentavalent impurities, indicating their competition for metal vacancies. However, we observe a broad positive correlation between OH bands at 3575 and 3525 cm-1 and Ti concentration, confirming the existence of a titanium clinohumite-like point defect. Nonetheless, Ti impurities do not exclusively control hydrogen incorporation in olivine due to the co-existence of other atomic impurities. Our results demonstrate that hydrogen behaves as an incompatible and opportunist element in olivine.

AB - Taking advantages of recent analytical advances, we investigate the potential coupled H and trace element incorporations in 17 olivine crystals from ten different localities. Olivine specimens were prepared as prismatic sections, and their major (micro X-ray fluorescence) and minor, trace, and ultra-trace element concentrations (laser ablation inductively coupled plasma mass spectrometry) were determined. Hydrogen concentrations were quantified using both unpolarized and polarized Fourier transform infrared spectroscopy (FTIR). Forsterite contents (= 100 × (Mg/Fe+Mg)) range from 83.2 to 94.1%, in agreement with the geological diversity of the crystals. Hydrogen concentrations range from 0 (dry) to 54 ppm H2O wt and are homogenous per crystal (except for one sample in which the H heterogeneity does not correlate to minor or trace element distributions). Total minor element concentrations range from 3487 to 6493 ppm, and are dominated by Ni, Mn, and Ca or B. Total rare earth element and extended trace element concentrations are very low (<1 ppm). Magmatic olivine (La Réunion, France) and hydrothermal olivine from a metamorphic setting (Norway) show the most and least atomic impurities, respectively, and mantle-derived olivines have concentrations between these two extremes. Combined with minor, trace, and ultra-trace element concentrations, the hydrogen concentrations and OH bands observed by FTIR reflect the geological diversity. Hydrogen concentrations are inversely correlated with di-, tri-, tetra-, and pentavalent impurities, indicating their competition for metal vacancies. However, we observe a broad positive correlation between OH bands at 3575 and 3525 cm-1 and Ti concentration, confirming the existence of a titanium clinohumite-like point defect. Nonetheless, Ti impurities do not exclusively control hydrogen incorporation in olivine due to the co-existence of other atomic impurities. Our results demonstrate that hydrogen behaves as an incompatible and opportunist element in olivine.

KW - MANTLE

KW - Peridotite

KW - Olivine

KW - Hydrogen

KW - TRACE-ELEMENTS

KW - FTIR analysis

KW - LA-ICP-MS

KW - Volatile Elements in Differentiated Planetary Interiors

M3 - Article

JO - Geochimica et Cosmochimica Acta

T2 - Geochimica et Cosmochimica Acta

JF - Geochimica et Cosmochimica Acta

SN - 0016-7037

M1 - GCA-S-19-01169

ER -