Abstract
Vibrational spectroscopy techniques such as Raman spectroscopy are sensitive to isotopic substitution into specific chemical groups within a material. This characteristic has been extensively exploited in the chemical sciences to trace reactions and identify which molecular groups are responsible for the formation of peaks within a spectrum. However, in the geosciences the use of isotopes and Raman spectroscopy is more limited due to the large enrichment required (several %) in comparison to the much smaller enrichments that occur due to isotopic fractionation (several ‰). Here we will show how Raman spectroscopy can provide unparalleled information into experimental mineral replacement reactions using isotopically enriched water.
Different components of the reacting system can be explored using Raman spectroscopy analysis of isotopic enrichment. Firstly, identification of isotope incorporation into the crystal structure indicates that a replacement reaction is fluid-mediated rather than a solid-state diffusional process [1,2]. Secondly, using kinetically controlled O-isotope substitution into oxyanion groups we can compare enrichment within different areas of a reaction rim to establish relative timings of precipitation events [3]. Thirdly, information about mechanism and timing obtained from isotope incorporation can be complimented with in-situ, correlated data of changes in crystallinity and orientation of mineral phases [4]. This technique has been shown to be applicable to replacement reactions including those of critical minerals such as feldspars [5] and carbonates [6]. Thus, it provides mineralogists with a unique method to probe the complex processes occurring during mineral replacement reactions.
[1] King et al. 2011 Am. Mineral., 96, 1503.
[2] Ruiz-Agudo et al. 2016 Geology, 44, 567.
[3] Jonas et al. 2014 Earth Planet. Sci. Lett., 386, 64.
[4] King et al. 2014 Cryst. Growth Des., 14, 3910.
[5] Niedermeier et al. 2009 Contrib. Miner. Petrol., 157, 65.
[6] Perdikouri et al. 2011 Geochem. Cosmochem. Acta, 75, 6211.
Different components of the reacting system can be explored using Raman spectroscopy analysis of isotopic enrichment. Firstly, identification of isotope incorporation into the crystal structure indicates that a replacement reaction is fluid-mediated rather than a solid-state diffusional process [1,2]. Secondly, using kinetically controlled O-isotope substitution into oxyanion groups we can compare enrichment within different areas of a reaction rim to establish relative timings of precipitation events [3]. Thirdly, information about mechanism and timing obtained from isotope incorporation can be complimented with in-situ, correlated data of changes in crystallinity and orientation of mineral phases [4]. This technique has been shown to be applicable to replacement reactions including those of critical minerals such as feldspars [5] and carbonates [6]. Thus, it provides mineralogists with a unique method to probe the complex processes occurring during mineral replacement reactions.
[1] King et al. 2011 Am. Mineral., 96, 1503.
[2] Ruiz-Agudo et al. 2016 Geology, 44, 567.
[3] Jonas et al. 2014 Earth Planet. Sci. Lett., 386, 64.
[4] King et al. 2014 Cryst. Growth Des., 14, 3910.
[5] Niedermeier et al. 2009 Contrib. Miner. Petrol., 157, 65.
[6] Perdikouri et al. 2011 Geochem. Cosmochem. Acta, 75, 6211.
| Original language | English |
|---|---|
| Publication status | Published - 2018 |
| Event | Nederlands Aardwetenschappelijk Congres 2018 - NH Koningshof, Veldhoven, Netherlands Duration: 15 Mar 2018 → 16 Mar 2018 https://www.nacgeo.nl |
Conference
| Conference | Nederlands Aardwetenschappelijk Congres 2018 |
|---|---|
| Abbreviated title | NAC 2018 |
| Country/Territory | Netherlands |
| City | Veldhoven |
| Period | 15/03/18 → 16/03/18 |
| Internet address |