Email this article Isotope effects attending decarbonation at high PT-parameters: experimental data
- Authors: Dubinina E.O.1, Palyanov Y.N.2
-
Affiliations:
- Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry, Russian Academy of Sciences
- V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences
- Issue: Vol 522, No 1 (2025)
- Pages: 27-33
- Section: GEOCHEMISTRY
- Submitted: 13.10.2025
- Published: 15.12.2025
- URL: https://journals.rcsi.science/2686-7397/article/view/326809
- DOI: https://doi.org/10.31857/S2686739725050033
- ID: 326809
Cite item
Open Access
Access granted
Subscription Access
Abstract
Isotope effects accompanying decarbonation process during the redox interaction of carbonate with metallic Fe and Ni at high PT parameters (1200°C, 6.3 GPa) were assessed. Under these conditions, carbonate decomposition proceeds with the formation of reduced carbon (ΣC: graphite, carbides, carbon dissolved in metal) and metal oxides (wustite, Mg-wustite). The isotope effect calculated using the models of batch and Rayleigh decarbonation for carbon isotopes in the ΣC-carbonate system ranged from 1.2 to 0.5‰, for oxygen isotopes in the Mg-wustite-carbonate system from 1.1 to 0.46‰. The obtained estimates show that during redox-induced decarbonation, isotopic shifts of oxygen and carbon in the residual carbonate are directed towards its enrichment in heavy isotopes 18O and 13C. This direction of the isotopic shift is opposite in sign to the isotopic effects that arise during decarbonation with the separation of CO2 at low pressures.
About the authors
E. O. Dubinina
Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry, Russian Academy of Sciences
Email: elenadelta@gmail.com
Moscow, Russia
Y. N. Palyanov
V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences
Email: elenadelta@gmail.com
Novosibirsk, Russia
References
- Baumgartner L.P., Valley J.W. Stable Isotope Transport and Contact Metamorphic Fluid Flow // Reviews in Mineralogy and Geochemistry. 2001. 43. 415–467. https://doi.org/10.2138/gsrmg.43.1.415
- Dubinina E.O., Nosova A.A., Avdeenko A.S., Aranovich L.Ya. Isotopic (Sr, Nd, O) systematics of the high Sr-Ba Late Miocene granitoid intrusions from the Caucasian Mineral Waters region // Petrology. 2010. 18. 211–238. https://doi.org/10.1134/S086959111003001X
- Bottinga Y. Calculation of fractionation factors for carbon and oxygen isotopic exchange in the system calcite-carbon dioxide-water // J. Phys. Chem. 1968. 72. 800‒808.
- Chacko T., Deines P. Theoretical calculation of oxygen isotope fractionation factors in carbonate systems // Geochimica et Cosmochimica Acta. 2008. 72. 3642–3660. https://doi.org/10.1016/j.gca.2008.06.001
- Носова А.А., Дубинина Е.О., Сазонова Л.В., Каргин А.В., Лебедева Н.М., Хвостиков В.А., Бурмий Ж.П., Кондрашов И.А., Третяченко В.В. Геохимия и изотопный состав кислорода оливинов из кимберлитов архангельской провинции (Россия): Вклад мантийного метасоматоза // Петрология. 2017. Т. 25. № 2. С. 135–167.
- Korolev N., Kopylova M., Dubinina E., Stern R. A. Contrasting oxygen isotopes in garnet from diamondiferous and barren eclogitic parageneses // Geochem. Persp. Let. 2023. 27. 15–19.
- Ickert R.B., Stachel T., Stern R.A., Harris J.W. Extreme 18 O-enrichment in majorite constrains a crustal origin of transition zone diamonds // Geochemical Perspectives Letters. 2015. 1. 65–74. https://doi.org/10.7185/geochemlet.1507
- Polyakov V.B., Kharlashina N.N. Effect of pressure on equilibrium isotopic fractionation // Geochim Cosmochim Acta. 1994. 58 (21): 4739–4750.
- Horita J., Polyakov V.B. Carbon-bearing iron phases and the carbon isotope composition of the deep Earth // PNAS. 2015. V. 112. № 1. 31–36.
- Пальянов Ю.Н., Баталева Ю.В., Борздов Ю.М., Куприянов И.Н., Нечаев Д.В. Экспериментальное моделирование мантийно-корового взаимодействия в системе металл‒карбонат, условия кристаллизации и индикаторные характеристики алмаза // Геология и геофизика. 2023. Вып. 8. 1073‒1094.
- Реутский В.Н., Борздов Ю.М., Баталева Ю.В., Пальянов Ю.Н. Распределение изотопов углерода в результате металл-карбонатного взаимодействия при мантийных РТ-параметрах // Геология и геофизика. 2023. Вып. 8. 1095‒1105.
- Palyanov Yu.N., Kupriyanov I.N., Khokhryakov A.F., Borzdov Yu.M. High-pressure crystallization and properties of diamond from magnesium-based catalysts // Cryst. Eng. Comm. 2017. V. 19. P. 4459‒4475.
- Palyanov Yu.N., Sokol A.G., Borzdov Yu.M., Khokhryakov A.F. Fluid-bearing alkaline carbonate melts as the medium for the formation of diamonds in the Earth’s mantle: an experimental study // Lithos. 2002. V. 60 (3–4). P. 145‒159.
- Palyanov Y.N., Bataleva Y.V., Sokol A.G., Borzdov Y.M., Kupriyanov I.N., Reutsky V.N., Sobolev N.V. Mantle–slab interaction and redox mechanism of diamond formation // PNAS. 2013. 110 (51).
- Sokol A.G., Borzdov Yu.M., Palyanov Yu.N., Khokhryakov A.F. High-temperature calibration of a multi-anvil high pressure apparatus // High Pressure Res. 2015. V. 35(2). P. 139‒147.
- Sharp Z.D. A laser-based microanalytical method for the in-situ determination of oxygen isotope ratios in silicates and oxides // Geochim. Cosmochim. Acta. 1990. 54. 1353–1357.
- Taylor P.Jr., Frechen J., Degens E.T. // Geochim.Cosmochim. Acta. 1967. 31. 407–430.
- Nikiforov A.V., Dubinina E.O., Polyakov N.A., Sugorakova A.M., Khertek A.K. Influence of Host Marble Rocks on the Formation of Intrusive Alkaline Rocks and Carbonatites of Sangilen (E. Siberia, Russia) // Minerals. 2021. 11. 666.
- Дубинина Е.О., Морозова А.С., Расс И.Т., Авдеенко А.С. Изотопное фракционирование кислорода в системе силикат–карбонат при формировании пород массива Ковдор (Кольский п-ов) // Доклады РАН. Науки о Земле. 2023. Т. 512. № 2. С. 51–57.
- Harte B. Diamond formation in the deep mantle: The record of mineral inclusions and their distribution in relation to mantle dehydration zones // Mineralogical Magazine. 2010. 74. 189–215.
Supplementary files
