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Structure and density of basaltic melts at mantle conditions from first-principles simulations

The origin and stability of deep-mantle melts, and the magmatic processes at different times of Earth's history are controlled by the physical properties of constituent silicate liquids. Here we report density functional theory-based simulations of model basalt, hydrous model basalt and near-MO...

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Detalles Bibliográficos
Autores principales: Bajgain, Suraj, Ghosh, Dipta B., Karki, Bijaya B.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Pub. Group 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4633951/
https://www.ncbi.nlm.nih.gov/pubmed/26450568
http://dx.doi.org/10.1038/ncomms9578
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author Bajgain, Suraj
Ghosh, Dipta B.
Karki, Bijaya B.
author_facet Bajgain, Suraj
Ghosh, Dipta B.
Karki, Bijaya B.
author_sort Bajgain, Suraj
collection PubMed
description The origin and stability of deep-mantle melts, and the magmatic processes at different times of Earth's history are controlled by the physical properties of constituent silicate liquids. Here we report density functional theory-based simulations of model basalt, hydrous model basalt and near-MORB to assess the effects of iron and water on the melt structure and density, respectively. Our results suggest that as pressure increases, all types of coordination between major cations and anions strongly increase, and the water speciation changes from isolated species to extended forms. These structural changes are responsible for rapid initial melt densification on compression thereby making these basaltic melts possibly buoyantly stable at one or more depths. Our finding that the melt-water system is ideal (nearly zero volume of mixing) and miscible (negative enthalpy of mixing) over most of the mantle conditions strengthens the idea of potential water enrichment of deep-mantle melts and early magma ocean.
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spelling pubmed-46339512015-11-25 Structure and density of basaltic melts at mantle conditions from first-principles simulations Bajgain, Suraj Ghosh, Dipta B. Karki, Bijaya B. Nat Commun Article The origin and stability of deep-mantle melts, and the magmatic processes at different times of Earth's history are controlled by the physical properties of constituent silicate liquids. Here we report density functional theory-based simulations of model basalt, hydrous model basalt and near-MORB to assess the effects of iron and water on the melt structure and density, respectively. Our results suggest that as pressure increases, all types of coordination between major cations and anions strongly increase, and the water speciation changes from isolated species to extended forms. These structural changes are responsible for rapid initial melt densification on compression thereby making these basaltic melts possibly buoyantly stable at one or more depths. Our finding that the melt-water system is ideal (nearly zero volume of mixing) and miscible (negative enthalpy of mixing) over most of the mantle conditions strengthens the idea of potential water enrichment of deep-mantle melts and early magma ocean. Nature Pub. Group 2015-10-09 /pmc/articles/PMC4633951/ /pubmed/26450568 http://dx.doi.org/10.1038/ncomms9578 Text en Copyright © 2015, Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved. http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
spellingShingle Article
Bajgain, Suraj
Ghosh, Dipta B.
Karki, Bijaya B.
Structure and density of basaltic melts at mantle conditions from first-principles simulations
title Structure and density of basaltic melts at mantle conditions from first-principles simulations
title_full Structure and density of basaltic melts at mantle conditions from first-principles simulations
title_fullStr Structure and density of basaltic melts at mantle conditions from first-principles simulations
title_full_unstemmed Structure and density of basaltic melts at mantle conditions from first-principles simulations
title_short Structure and density of basaltic melts at mantle conditions from first-principles simulations
title_sort structure and density of basaltic melts at mantle conditions from first-principles simulations
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4633951/
https://www.ncbi.nlm.nih.gov/pubmed/26450568
http://dx.doi.org/10.1038/ncomms9578
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