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Dong XH, Wang SJ, Wang W, Huang S, Li QL, Liu C, Gao T, Li S, Wu S. Highly oxidized intraplate basalts and deep carbon storage. SCIENCE ADVANCES 2024; 10:eadm8138. [PMID: 39110790 PMCID: PMC11305372 DOI: 10.1126/sciadv.adm8138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 06/28/2024] [Indexed: 08/10/2024]
Abstract
Deep carbon cycle is crucial for mantle dynamics and maintaining Earth's habitability. Recycled carbonates are a strong oxidant in mantle carbon-iron redox reactions, leading to the formation of highly oxidized mantle domains and deep carbon storage. Here we report high Fe3+/∑Fe values in Cenozoic intraplate basalts from eastern China, which are correlated with geochemical and isotopic compositions that point to a common role of carbonated melt with recycled carbonate signatures. We propose that the source of these highly oxidized basalts has been oxidized by carbonated melts derived from the stagnant subducted slab in the mantle transition zone. Diamonds formed during the carbon-iron redox reaction were separated from the melt due to density differences. This would leave a large amount of carbon (about four times of preindustrial atmospheric carbon budget) stored in the deep mantle and isolated from global carbon cycle. As such, the amounts of subducted slabs stagnated at mantle transition zone can be an important factor regulating the climate.
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Affiliation(s)
- Xu-Han Dong
- State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences (Beijing), Beijing 100083, China
| | - Shui-Jiong Wang
- State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences (Beijing), Beijing 100083, China
- Frontiers Science Center for Deep-time Digital Earth, China University of Geosciences (Beijing), Beijing 100083, China
| | - Wenzhong Wang
- School of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Comparative Planetology, USTC, Hefei, China
- National Geophysical Observatory at Mengcheng, USTC, Mengcheng, China
| | - Shichun Huang
- Department of Earth, Environmental, and Planetary Sciences, University of Tennessee, Knoxville, TN 37996-1410, USA
| | - Qiu-Li Li
- State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
| | - Chengshuai Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Ting Gao
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Shuguang Li
- State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences (Beijing), Beijing 100083, China
| | - Shitou Wu
- State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
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Davis AH, Chidester BA, Greenberg E, Prakapenka VB, Campbell AJ. Carbonate-Metal Reactions in the Lower Mantle. ACS EARTH & SPACE CHEMISTRY 2024; 8:654-664. [PMID: 38654897 PMCID: PMC11033939 DOI: 10.1021/acsearthspacechem.3c00101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 03/04/2024] [Accepted: 03/15/2024] [Indexed: 04/26/2024]
Abstract
Carbonates are important carbon-bearing phases in the mantle. While their role in upper mantle petrologic processes has been well studied, their effect on phase relations, melting, and transport properties in the lower mantle is less understood. The stability of carbonates in the mantle depends on a host of factors, including pressure, temperature, oxygen fugacity, and reactions with surrounding mantle phases. To understand the stability of carbonates in the presence of metal in the lower mantle, carbonate-metal reaction experiments on the Fe-Si-Ca-Mg-C-O system were conducted up to 124 GPa and 3200 K. We find that carbonates react with iron alloys to form silicates, iron carbides, and oxides. However, the temperature at which these reactions occur increases with pressure, indicating that along a geotherm in the lowermost mantle carbonates are the stable carbon-bearing phase. Carbon is found to be less siderophilic at high-pressure compared to silicon.
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Affiliation(s)
- Anne H. Davis
- Department
of the Geophysical Sciences, The University
of Chicago, 5734 S. Ellis Avenue, Chicago, Illinois 60637, United States
| | | | - Eran Greenberg
- Center
for Advanced Radiation Sources, The University
of Chicago, 5734 S. Ellis
Avenue, Chicago, Illinois 60637, United States
| | - Vitali B. Prakapenka
- Center
for Advanced Radiation Sources, The University
of Chicago, 5734 S. Ellis
Avenue, Chicago, Illinois 60637, United States
| | - Andrew J. Campbell
- Department
of the Geophysical Sciences, The University
of Chicago, 5734 S. Ellis Avenue, Chicago, Illinois 60637, United States
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Bayarjargal L, Spahr D, Milman V, Marquardt J, Giordano N, Winkler B. Anhydrous Aluminum Carbonates and Isostructural Compounds. Inorg Chem 2023; 62:13910-13918. [PMID: 37579301 DOI: 10.1021/acs.inorgchem.3c01832] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/16/2023]
Abstract
We synthesized the inorganic anhydrous aluminum carbonates Al2[C2O5][CO3]2 and Al2[CO3]3 by reacting Al2O3 with CO2 at high pressures and temperatures and characterized them by Raman spectroscopy. Their structures were solved by X-ray diffraction. Al2[CO3]3 forms at around 24-28 GPa, while Al2[C2O5][CO3]2 forms above 38(3) GPa. The distinguishing feature of the new Al2[C2O5][CO3]2-structure type is the presence of pyrocarbonate [C2O5]2--groups, trigonal [CO3]2─groups, and octahedrally coordinated trivalent cations. Al2[CO3]3 has isolated [CO3]2--groups. Both Al-carbonates can be recovered under ambient conditions. Density functional theory calculations predict that CO2 will react with Fe2O3, Ti2O3, Ga2O3, In2O3, and MgSiO3 at high pressures to form compounds which are isostructural to Al2[C2O5][CO3]2. MgSi[C2O5][CO3]2 is predicted to be stable at pressures relative to abundant mantle minerals in the presence of CO2. This structure type allows the incorporation of four elements (Mg, Si, Fe, and Al) abundant in the Earth's mantle in octahedral coordination and provides an alternative phase with novel carbon speciation for carbon storage in the deep Earth.
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Affiliation(s)
- Lkhamsuren Bayarjargal
- Institute of Geosciences, Goethe University Frankfurt, Altenhöferallee 1, Frankfurt 60438, Germany
| | - Dominik Spahr
- Institute of Geosciences, Goethe University Frankfurt, Altenhöferallee 1, Frankfurt 60438, Germany
| | - Victor Milman
- Dassault Systèmes BIOVIA, 334 Cambridge Science Park, Cambridge CB4 0WN, U.K
| | - Julien Marquardt
- Institute of Geosciences, Goethe University Frankfurt, Altenhöferallee 1, Frankfurt 60438, Germany
| | - Nico Giordano
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, Hamburg 22607, Germany
| | - Björn Winkler
- Institute of Geosciences, Goethe University Frankfurt, Altenhöferallee 1, Frankfurt 60438, Germany
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Bajgain SK, Ashley AW, Mookherjee M, Ghosh DB, Karki BB. Insights into magma ocean dynamics from the transport properties of basaltic melt. Nat Commun 2022; 13:7590. [PMID: 36481757 PMCID: PMC9731987 DOI: 10.1038/s41467-022-35171-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 11/17/2022] [Indexed: 12/13/2022] Open
Abstract
The viscosity of magma plays a crucial role in the dynamics of the Earth: from the crystallization of a magma ocean during its initial stages to modern-day volcanic processes. However, the pressure-dependence behavior of viscosity at high pressure remains controversial. In this study, we report the results of first-principles molecular dynamics simulations of basaltic melt to show that the melt viscosity increases upon compression along each isotherm for the entire lower mantle after showing minima at ~6 GPa. However, elevated temperatures of the magma ocean translate to a narrow range of viscosity, i.e., 0.01-0.03 Pa.s. This low viscosity implies that the crystallization of the magma ocean could be complete within a few million years. These results also suggest that the crystallization of the magma ocean is likely to be fractional, thus supporting the hypothesis that present-day mantle heterogeneities could have been generated during the early crystallization of the primitive mantle.
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Affiliation(s)
- Suraj K Bajgain
- Earth Materials Laboratory, Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL, USA.
- Department of Geology, School of Natural Resources & Environment, Lake Superior State University, Sault Ste Marie, MI, USA.
| | - Aaron Wolfgang Ashley
- Earth Materials Laboratory, Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL, USA
| | - Mainak Mookherjee
- Earth Materials Laboratory, Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL, USA.
| | - Dipta B Ghosh
- School of Electrical Engineering and Computer Science, Department of Geology and Geophysics, Center for Computation and Technology, Louisiana State University, Baton Rouge, LA, USA
| | - Bijaya B Karki
- School of Electrical Engineering and Computer Science, Department of Geology and Geophysics, Center for Computation and Technology, Louisiana State University, Baton Rouge, LA, USA.
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Davis AH, Solomatova NV, Campbell AJ, Caracas R. The Speciation and Coordination of a Deep Earth Carbonate-Silicate-Metal Melt. JOURNAL OF GEOPHYSICAL RESEARCH. SOLID EARTH 2022; 127:e2021JB023314. [PMID: 35866035 PMCID: PMC9286813 DOI: 10.1029/2021jb023314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 02/05/2022] [Accepted: 03/07/2022] [Indexed: 06/15/2023]
Abstract
Ab initio molecular dynamics calculations on a carbonate-silicate-metal melt were performed to study speciation and coordination changes as a function of pressure and temperature. We examine in detail the bond abundances of specific element pairs and the distribution of coordination environments over conditions spanning Earth's present-day mantle. Average coordination numbers increase continuously from 4 to 8 for Fe and Mg, from 4 to 6 for Si, and from 2 to 4 for C from 1 to 148 GPa (4,000 K). Speciation across all pressure and temperature conditions is complex due to the unusual bonding of carbon. With the increasing pressure, C-C and C-Fe bonding increase significantly, resulting in the formation of carbon polymers, C-Fe clusters, and the loss of carbonate groups. The increased bonding of carbon with elements other than oxygen indicates that carbon begins to replace oxygen as an anion in the melt network. We evaluate our results in the context of diamond formation and of metal-silicate partitioning behavior of carbon. Our work has implications for properties of carbon and metal-bearing silicate melts, such as viscosity, electrical conductivity, and reactivity with surrounding phases.
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Affiliation(s)
- A. H. Davis
- Department of the Geophysical SciencesUniversity of ChicagoChicagoILUSA
| | - N. V. Solomatova
- CNRSEcole Normale Supérieure de LyonLaboratoire de Géologie de Lyon LGLTPE UMR5276Centre Blaise PascalLyonFrance
| | - A. J. Campbell
- Department of the Geophysical SciencesUniversity of ChicagoChicagoILUSA
| | - R. Caracas
- CNRSEcole Normale Supérieure de LyonLaboratoire de Géologie de Lyon LGLTPE UMR5276Centre Blaise PascalLyonFrance
- The Center for Earth Evolution and Dynamics (CEED)University of OsloOsloNorway
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Moog M, Pietrucci F, Saitta AM. Carbon Dioxide under Earth Mantle Conditions: From a Molecular Liquid through a Reactive Fluid to Polymeric Regimes. J Phys Chem A 2021; 125:5863-5869. [PMID: 34228460 DOI: 10.1021/acs.jpca.1c01026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In both its gaseous and condensed forms, carbon dioxide has an ever-increasing impact on Earth's chemistry and human life and activities. However, many aspects of its high-pressure phase diagram remain unclear. In this work, we present a complete structural characterization of carbon dioxide fluids under geological conditions using extensive ab initio molecular dynamics simulations throughout a wide pressure and temperature range, corresponding to Earth's lower mantle. We identify and describe four different disordered regimes, including two polymeric forms and two molecular ones, all within the geothermal conditions of the lower mantle. At pressures below 40 GPa, we find that the molecular liquid becomes very reactive above 2000 K: the C-O double bond routinely breaks, resulting in small and transient chains composed of CO2 units and frequently leading to an exchange of oxygen atoms between molecules. At higher pressures, in addition to the polymeric fluid previously reported at 3000 K, we find a polymeric system with glass-like behavior at lower temperatures, suggesting a complex interplay between kinetics and stability.
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Affiliation(s)
- Mathieu Moog
- Muséum National d'Histoire Naturelle, Institut de Recherche pour le Développement, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Sorbonne Université, UMR CNRS 7590, 75252 Paris, France
| | - Fabio Pietrucci
- Muséum National d'Histoire Naturelle, Institut de Recherche pour le Développement, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Sorbonne Université, UMR CNRS 7590, 75252 Paris, France
| | - A Marco Saitta
- Muséum National d'Histoire Naturelle, Institut de Recherche pour le Développement, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Sorbonne Université, UMR CNRS 7590, 75252 Paris, France
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Solomatova NV, Caracas R. Buoyancy and Structure of Volatile-Rich Silicate Melts. JOURNAL OF GEOPHYSICAL RESEARCH. SOLID EARTH 2021; 126:e2020JB021045. [PMID: 33680690 PMCID: PMC7900987 DOI: 10.1029/2020jb021045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 12/17/2020] [Accepted: 12/20/2020] [Indexed: 06/12/2023]
Abstract
The early Earth was marked by at least one global magma ocean. Melt buoyancy played a major role for its evolution. Here we model the composition of the magma ocean using a six-component pyrolite melt, to which we add volatiles in the form of carbon as molecular CO or CO2 and hydrogen as molecular H2O or through substitution for magnesium. We compute the density relations from first-principles molecular dynamics simulations. We find that the addition of volatiles renders all the melts more buoyant compared to the reference volatile-free pyrolite. The effect is pressure dependent, largest at the surface, decreasing to about 20 GPa, and remaining roughly constant to 135 GPa. The increased buoyancy would have enhanced convection and turbulence, and thus promoted the chemical exchanges of the magma ocean with the early atmosphere. We determine the partial molar volume of both H2O and CO2 throughout the magma ocean conditions. We find a pronounced dependence with temperature at low pressures, whereas at megabar pressures the partial molar volumes are independent of temperature. At all pressures, the polymerization of the silicate melt is strongly affected by the amount of oxygen added to the system while being only weakly affected by the specific type of volatile added.
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Affiliation(s)
- Natalia V. Solomatova
- CNRSEcole Normale Supérieure de LyonLaboratoire de Géologie de Lyon LGLTPE UMR5276Centre Blaise PascalLyonFrance
| | - Razvan Caracas
- CNRSEcole Normale Supérieure de LyonLaboratoire de Géologie de Lyon LGLTPE UMR5276Centre Blaise PascalLyonFrance
- The Center for Earth Evolution and Dynamics (CEED)University of OsloOsloNorway
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