Water Speciation and Storage Capacity of Olivine under the Reduced Fluid—Peridotite Interaction
The key features of the interaction between peridotites of the continental lithospheric mantle and reduced hydrocarbon-rich fluids have been studied in experiments conducted at 5.5 GPa and 1200 °C. Under this interaction, the original harzburgite undergoes recrystallization while the composition of...
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MDPI AG
2024-01-01
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| Series: | Minerals |
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| Online Access: | https://www.mdpi.com/2075-163X/14/2/119 |
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| author | Igor N. Kupriyanov Alexander G. Sokol Alexey N. Kruk |
| author_facet | Igor N. Kupriyanov Alexander G. Sokol Alexey N. Kruk |
| author_sort | Igor N. Kupriyanov |
| collection | DOAJ |
| description | The key features of the interaction between peridotites of the continental lithospheric mantle and reduced hydrocarbon-rich fluids have been studied in experiments conducted at 5.5 GPa and 1200 °C. Under this interaction, the original harzburgite undergoes recrystallization while the composition of the fluid changes from CH<sub>4</sub>-H<sub>2</sub>O to H<sub>2</sub>O-rich with a small amount of CO<sub>2</sub>. The oxygen fugacity in the experiments varied from the iron-wustite (IW) to enstatite-magnesite-olivine-graphite/diamond (EMOG) buffers. Olivines recrystallized in the interaction between harzburgite and a fluid generated by the decomposition of stearic acid contain inclusions composed of graphite and methane with traces of ethane and hydrogen. The water content of such olivines slightly exceeds that of the original harzburgite. Redox metasomatism, which involves the oxidation of hydrocarbons in the fluid by reaction with magnesite-bearing peridotite, leads to the appearance of additional OH absorption bands in the infrared spectra of olivines. The water content of olivine in this case increases by approximately two times, reaching 160–180 wt. ppm. When hydrocarbons are oxidized by interaction with hematite-bearing peridotite, olivine captures Ca-Mg-Fe carbonates, which are products of carbonate melt quenching. This oxidative metasomatism is characterized by the appearance of specific OH absorption bands and a significant increase in the total water content in olivine of up to 500–600 wt. ppm. These findings contribute to the development of criteria for reconstructing metasomatic transformations in mantle rocks based on the infrared spectra and water content of olivines. |
| first_indexed | 2024-03-07T22:19:42Z |
| format | Article |
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| language | English |
| last_indexed | 2024-03-07T22:19:42Z |
| publishDate | 2024-01-01 |
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| record_format | Article |
| series | Minerals |
| spelling | doaj.art-49895396c98c4118b7b72033533a73102024-02-23T15:28:30ZengMDPI AGMinerals2075-163X2024-01-0114211910.3390/min14020119Water Speciation and Storage Capacity of Olivine under the Reduced Fluid—Peridotite InteractionIgor N. Kupriyanov0Alexander G. Sokol1Alexey N. Kruk2V.S. Sobolev Institute of Geology and Mineralogy SB RAS, Koptyug Ave. 3, 630090 Novosibirsk, RussiaV.S. Sobolev Institute of Geology and Mineralogy SB RAS, Koptyug Ave. 3, 630090 Novosibirsk, RussiaV.S. Sobolev Institute of Geology and Mineralogy SB RAS, Koptyug Ave. 3, 630090 Novosibirsk, RussiaThe key features of the interaction between peridotites of the continental lithospheric mantle and reduced hydrocarbon-rich fluids have been studied in experiments conducted at 5.5 GPa and 1200 °C. Under this interaction, the original harzburgite undergoes recrystallization while the composition of the fluid changes from CH<sub>4</sub>-H<sub>2</sub>O to H<sub>2</sub>O-rich with a small amount of CO<sub>2</sub>. The oxygen fugacity in the experiments varied from the iron-wustite (IW) to enstatite-magnesite-olivine-graphite/diamond (EMOG) buffers. Olivines recrystallized in the interaction between harzburgite and a fluid generated by the decomposition of stearic acid contain inclusions composed of graphite and methane with traces of ethane and hydrogen. The water content of such olivines slightly exceeds that of the original harzburgite. Redox metasomatism, which involves the oxidation of hydrocarbons in the fluid by reaction with magnesite-bearing peridotite, leads to the appearance of additional OH absorption bands in the infrared spectra of olivines. The water content of olivine in this case increases by approximately two times, reaching 160–180 wt. ppm. When hydrocarbons are oxidized by interaction with hematite-bearing peridotite, olivine captures Ca-Mg-Fe carbonates, which are products of carbonate melt quenching. This oxidative metasomatism is characterized by the appearance of specific OH absorption bands and a significant increase in the total water content in olivine of up to 500–600 wt. ppm. These findings contribute to the development of criteria for reconstructing metasomatic transformations in mantle rocks based on the infrared spectra and water content of olivines.https://www.mdpi.com/2075-163X/14/2/119mantle peridotitemetasomatismreduced fluidhydrocarbonsolivinenominally anhydrous minerals |
| spellingShingle | Igor N. Kupriyanov Alexander G. Sokol Alexey N. Kruk Water Speciation and Storage Capacity of Olivine under the Reduced Fluid—Peridotite Interaction Minerals mantle peridotite metasomatism reduced fluid hydrocarbons olivine nominally anhydrous minerals |
| title | Water Speciation and Storage Capacity of Olivine under the Reduced Fluid—Peridotite Interaction |
| title_full | Water Speciation and Storage Capacity of Olivine under the Reduced Fluid—Peridotite Interaction |
| title_fullStr | Water Speciation and Storage Capacity of Olivine under the Reduced Fluid—Peridotite Interaction |
| title_full_unstemmed | Water Speciation and Storage Capacity of Olivine under the Reduced Fluid—Peridotite Interaction |
| title_short | Water Speciation and Storage Capacity of Olivine under the Reduced Fluid—Peridotite Interaction |
| title_sort | water speciation and storage capacity of olivine under the reduced fluid peridotite interaction |
| topic | mantle peridotite metasomatism reduced fluid hydrocarbons olivine nominally anhydrous minerals |
| url | https://www.mdpi.com/2075-163X/14/2/119 |
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