Extreme silicon isotope fractionation due to Si organic complexation: Implications for silica biomineralization
(2020) In Earth and Planetary Science Letters 541.- Abstract
- A combination of theoretical predictions and isotopic equilibration experiments using the three-isotope method have been performed to assess Si isotope fractionation among minerals, and aqueous species in the presence of dissolved catechol. Aqueous Si in abiotic ambient temperature aqueous solutions is dominated by the IV-coordinated H4SiO04species, but the presence of aqueous catechol provokes the formation of a VI-fold Si-catechol complex. Results show an equilibrium Si fractionation factor of ∼19between the VI-fold coordinated Si-catechol complex and the IV-fold coordinated aqueous silicic acid, an amplitude never previously observed for silicon. The fractionation between V-fold Si-organo complexes (with diolate, glyconate or... (More)
- A combination of theoretical predictions and isotopic equilibration experiments using the three-isotope method have been performed to assess Si isotope fractionation among minerals, and aqueous species in the presence of dissolved catechol. Aqueous Si in abiotic ambient temperature aqueous solutions is dominated by the IV-coordinated H4SiO04species, but the presence of aqueous catechol provokes the formation of a VI-fold Si-catechol complex. Results show an equilibrium Si fractionation factor of ∼19between the VI-fold coordinated Si-catechol complex and the IV-fold coordinated aqueous silicic acid, an amplitude never previously observed for silicon. The fractionation between V-fold Si-organo complexes (with diolate, glyconate or methyllactate groups) and silicic acid has also been estimated through theoretical predictions to be about −10. These extreme fractionations can be used to improve our ability to interpret the Si isotope compositions of natural solids, and in particular those associated with marine silica biomineralization processes (e.g. sponge spicules). (Less)
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https://lup.lub.lu.se/record/131d3d37-ad29-445f-89c8-a7e58d05f839
- author
- Stamm, Franziska M. LU ; Méheut, Merlin ; Zambardi, Thomas ; Chmeleff, Jérôme ; Schott, Jacques and Oelkers, Eric
- organization
- publishing date
- 2020-05-05
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- silicon, equilibrium isotope fractionation, organo-silicon complexes, first principle calculation, three-isotope method, Si coordination change
- in
- Earth and Planetary Science Letters
- volume
- 541
- article number
- 116287
- pages
- 12 pages
- publisher
- Elsevier
- external identifiers
-
- scopus:85084190709
- ISSN
- 0012-821X
- DOI
- 10.1016/j.epsl.2020.116287
- language
- English
- LU publication?
- yes
- id
- 131d3d37-ad29-445f-89c8-a7e58d05f839
- date added to LUP
- 2021-01-22 19:12:26
- date last changed
- 2022-04-26 23:50:51
@article{131d3d37-ad29-445f-89c8-a7e58d05f839, abstract = {{A combination of theoretical predictions and isotopic equilibration experiments using the three-isotope method have been performed to assess Si isotope fractionation among minerals, and aqueous species in the presence of dissolved catechol. Aqueous Si in abiotic ambient temperature aqueous solutions is dominated by the IV-coordinated H4SiO04species, but the presence of aqueous catechol provokes the formation of a VI-fold Si-catechol complex. Results show an equilibrium Si fractionation factor of ∼19between the VI-fold coordinated Si-catechol complex and the IV-fold coordinated aqueous silicic acid, an amplitude never previously observed for silicon. The fractionation between V-fold Si-organo complexes (with diolate, glyconate or methyllactate groups) and silicic acid has also been estimated through theoretical predictions to be about −10. These extreme fractionations can be used to improve our ability to interpret the Si isotope compositions of natural solids, and in particular those associated with marine silica biomineralization processes (e.g. sponge spicules).}}, author = {{Stamm, Franziska M. and Méheut, Merlin and Zambardi, Thomas and Chmeleff, Jérôme and Schott, Jacques and Oelkers, Eric}}, issn = {{0012-821X}}, keywords = {{silicon; equilibrium isotope fractionation; organo-silicon complexes; first principle calculation; three-isotope method; Si coordination change}}, language = {{eng}}, month = {{05}}, publisher = {{Elsevier}}, series = {{Earth and Planetary Science Letters}}, title = {{Extreme silicon isotope fractionation due to Si organic complexation: Implications for silica biomineralization}}, url = {{http://dx.doi.org/10.1016/j.epsl.2020.116287}}, doi = {{10.1016/j.epsl.2020.116287}}, volume = {{541}}, year = {{2020}}, }