The University of Southampton
University of Southampton Institutional Repository
Warning ePrints Soton is experiencing an issue with some file downloads not being available. We are working hard to fix this. Please bear with us.

Exploration of driving mechanisms of equilibrium boron isotope fractionation in tourmaline group minerals and fluid: A density functional theory study

Exploration of driving mechanisms of equilibrium boron isotope fractionation in tourmaline group minerals and fluid: A density functional theory study
Exploration of driving mechanisms of equilibrium boron isotope fractionation in tourmaline group minerals and fluid: A density functional theory study
The equilibrium boron isotope fractionations (α3–4, Δ11B(Tur-fluid)) between tourmaline mineral groups and fluids at 0.5 GPa, 600–1000 K are investigated using density functional theory calculations. The first solvent shell controls boron isotope fractionation in solution, where the β values of both H3BO3 and B(OH)4− decrease with increasing numbers of hydrogen bonds. In supercritical fluids, the weakening of hydrogen bonds and the diversity in configurations of hydrated boron species both contribute to variations in the vibrational frequencies. The 1000lnαTur-fluid value increases with increasing Mg/(Fe+Mg) ratios in the dravite-schorl solid solution series. This effect, together with the crystallization sequence predicted from the Gibbs free energies of tourmaline formation, accounts well for the association of boron isotope and chemical zonation observed in zoned tourmaline grains. The dependence of boron isotope fractionation on the BO bond length in tourmaline group minerals reflects the changes in relevant molar volumes caused by differences in the mass and charge of the atoms occupying the X, Y, and Z sites of tourmalines. This study suggests that the chemical composition of the tourmaline plays an important role in controlling the boron isotope composition in tourmalines crystallized from hydrothermal systems.
Boron isotope fractionation, Fluid, Reduced partition function ratio (RPFR), Tourmaline group minerals
0009-2541
1-14
Li, Yin-chuan
5f9307cf-80a5-4ac8-a6bb-bd678b5206fe
Chen, Hong-wei
0f30c1b9-7831-4010-a81c-c6825f78af16
Wei, Hai-zhen
60e6342b-b6d2-4ac6-a4d5-a1dec963b1a7
Jiang, Shao-yong
dc929006-69ac-4366-bf2b-dc97527602d3
Palmer, Martin R.
d2e60e81-5d6e-4ddb-a243-602537286080
Van De Ven, T.g.m.
555ff606-e3f1-4e23-ab26-232151b18877
Hohl, Simon
beb9f599-7734-4994-9cbc-5bd590ded0f3
Lu, Jian-jun
a5102598-bc25-4892-b6c4-7ac803412055
Ma, Jing
3495e3ca-6f13-42ae-8b6a-7d8d4e3166fe
Li, Yin-chuan
5f9307cf-80a5-4ac8-a6bb-bd678b5206fe
Chen, Hong-wei
0f30c1b9-7831-4010-a81c-c6825f78af16
Wei, Hai-zhen
60e6342b-b6d2-4ac6-a4d5-a1dec963b1a7
Jiang, Shao-yong
dc929006-69ac-4366-bf2b-dc97527602d3
Palmer, Martin R.
d2e60e81-5d6e-4ddb-a243-602537286080
Van De Ven, T.g.m.
555ff606-e3f1-4e23-ab26-232151b18877
Hohl, Simon
beb9f599-7734-4994-9cbc-5bd590ded0f3
Lu, Jian-jun
a5102598-bc25-4892-b6c4-7ac803412055
Ma, Jing
3495e3ca-6f13-42ae-8b6a-7d8d4e3166fe

Li, Yin-chuan, Chen, Hong-wei, Wei, Hai-zhen, Jiang, Shao-yong, Palmer, Martin R., Van De Ven, T.g.m., Hohl, Simon, Lu, Jian-jun and Ma, Jing (2020) Exploration of driving mechanisms of equilibrium boron isotope fractionation in tourmaline group minerals and fluid: A density functional theory study. Chemical Geology, 536, 1-14, [119466]. (doi:10.1016/j.chemgeo.2020.119466).

Record type: Article

Abstract

The equilibrium boron isotope fractionations (α3–4, Δ11B(Tur-fluid)) between tourmaline mineral groups and fluids at 0.5 GPa, 600–1000 K are investigated using density functional theory calculations. The first solvent shell controls boron isotope fractionation in solution, where the β values of both H3BO3 and B(OH)4− decrease with increasing numbers of hydrogen bonds. In supercritical fluids, the weakening of hydrogen bonds and the diversity in configurations of hydrated boron species both contribute to variations in the vibrational frequencies. The 1000lnαTur-fluid value increases with increasing Mg/(Fe+Mg) ratios in the dravite-schorl solid solution series. This effect, together with the crystallization sequence predicted from the Gibbs free energies of tourmaline formation, accounts well for the association of boron isotope and chemical zonation observed in zoned tourmaline grains. The dependence of boron isotope fractionation on the BO bond length in tourmaline group minerals reflects the changes in relevant molar volumes caused by differences in the mass and charge of the atoms occupying the X, Y, and Z sites of tourmalines. This study suggests that the chemical composition of the tourmaline plays an important role in controlling the boron isotope composition in tourmalines crystallized from hydrothermal systems.

Text
Exploration_of_driving_mechanisms_of_equilibrium_boron_isotope_fractionation_in_tourmaline_group_minerals_and_fluid - Accepted Manuscript
Download (2MB)
Text
Exploration of driving mechanisms of equilibrium boron isotope fractionation in tourmaline group minerals and fluid Accepted Manuscript
Restricted to Repository staff only
Request a copy

More information

Accepted/In Press date: 8 January 2020
e-pub ahead of print date: 13 January 2020
Published date: 20 March 2020
Keywords: Boron isotope fractionation, Fluid, Reduced partition function ratio (RPFR), Tourmaline group minerals

Identifiers

Local EPrints ID: 437621
URI: http://eprints.soton.ac.uk/id/eprint/437621
ISSN: 0009-2541
PURE UUID: 8c0ee5f9-d58c-477b-abb4-7c2b31064cd8

Catalogue record

Date deposited: 06 Feb 2020 17:34
Last modified: 26 Nov 2021 05:17

Export record

Altmetrics

Contributors

Author: Yin-chuan Li
Author: Hong-wei Chen
Author: Hai-zhen Wei
Author: Shao-yong Jiang
Author: T.g.m. Van De Ven
Author: Simon Hohl
Author: Jian-jun Lu
Author: Jing Ma

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×