Title | Clumped isotope temperature calibration for calcite: bridging theory and experimentation |
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Author | Jautzy, J J ;
Savard, M M; Dhillon, R S; Bernasconi, S M; Smirnoff, A |
Source | Geochemical Perspectives Letters vol. 14, 2020 p. 36-41, https://doi.org/10.7185/geochemlet.2021 Open Access |
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Year | 2020 |
Alt Series | Natural Resources Canada, Contribution Series 20190528 |
Publisher | European Association of Geochemistry |
Document | serial |
Lang. | English |
Media | on-line; digital |
File format | pdf; html |
Subjects | geochemistry; Science and Technology; calcite; isotopic studies; isotopes; oxygen isotopes; carbonates |
Illustrations | plots; models |
Program | GEM: Geo-mapping for Energy and Minerals Geomapping for Energy & Minerals (GEM) - Geo-mapping Frontiers |
Released | 2020 07 07 |
Abstract | Clumped isotopes (delta-47) analysis in carbonates is becoming widespread across the geochemical community as a geothermometer that also allows for the reconstruction of the precipitating fluid
delta-18O composition. While initial delta-47-temperature relationship discrepancies between laboratories have been considerably reduced over the past 10 years, theoretical temperature calibration and laboratory experimental efforts have still not
converged to common ground. Moreover, a lack of high temperature anchor points has weakened its application to high temperature calcite formation. Here we present a temperature calibration for carbonate clumped isotopes between 5 and 726 °C, using
synthetically precipitated and heated calcites, to extend the calcite delta-47-temperature calibration to higher temperatures. By showing a strong agreement between the empirical calibration proposed here, theoretical and all recently published
T-calibrations made using a full carbonate referencing scheme, this study: (1) provides a calibration allowing more precise application in high temperature geological systems, (2) further supports the improvement of inter-laboratory comparison by
using carbonate standards, (3) reconciles empirical temperature calibrations with theory. |
Summary | (Plain Language Summary, not published) Technological advances have allowed measuring the quantity of bonds between two heavy isotopes (also called "clumping") in carbonate minerals. As this
"clumping" is directly related to the carbonate formation temperature, a new geothermometer has emerged. Over the past fifteen years, the relationship between the abundance of clumping and the formation temperature of carbonates has been
characterized theoretically and experimentally. However, up to now, calibration at high temperature were problematic; moreover, theoretical and experimental calibrations were not reconciled. Here we report a T-calibration for this new geothermometer
from 5 to 750°C that reconciles theory and experimentation. We compared the proposed calibration with all the most recent ones published in the literature and revealed significant similarities between all of them. This new T-calibration can be
utilized to understand the temperature of formation of carbonate in high temperature geological contexts such as hydrothermal related ore deposit formation. |
GEOSCAN ID | 321797 |
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