Iron isotopes trace primordial magma ocean cumulates melting in the Earth’s upper mantle
The differentiation of the Earth ~ 4.5 Ga is believed to have culminated in magma ocean crystallization, crystal-liquid separation and the formation of mineralogically distinct mantle reservoirs. However, the magma ocean model remains difficult to validate due to the scarcity of geochemical tracers...
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American Association for the Advancement of Science
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ftunivcam:oai:www.repository.cam.ac.uk:1810/319861 2024-01-14T10:07:20+01:00 Iron isotopes trace primordial magma ocean cumulates melting in the Earth’s upper mantle Williams, Helen Matthews, Simon Rizo, Hanika Shorttle, O 2021-03-10 application/pdf https://www.repository.cam.ac.uk/handle/1810/319861 https://doi.org/10.17863/CAM.66986 eng eng American Association for the Advancement of Science http://dx.doi.org/10.1126/sciadv.abc7394 Science Advances https://www.repository.cam.ac.uk/handle/1810/319861 doi:10.17863/CAM.66986 Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ 37 Earth Sciences 3703 Geochemistry 3705 Geology 3706 Geophysics 14 Life Below Water Article 2021 ftunivcam https://doi.org/10.17863/CAM.66986 2023-12-21T23:19:24Z The differentiation of the Earth ~ 4.5 Ga is believed to have culminated in magma ocean crystallization, crystal-liquid separation and the formation of mineralogically distinct mantle reservoirs. However, the magma ocean model remains difficult to validate due to the scarcity of geochemical tracers of lower mantle mineralogy. The Fe isotope compositions (57Fe) of ancient mafic rocks can be used to reconstruct the mineralogy of their mantle source regions. We present Fe isotope data for 3.7 Ga metabasalts from the Isua Supracrustal Belt (Greenland). The 57Fe signatures of these samples extend to values elevated relative to modern equivalents and define strong correlations with fluid-immobile trace elements and tungsten isotope anomalies (182W). Phase equilibria models demonstrate that these features can be explained by melting of a magma ocean cumulate component in the upper mantle. Similar processes may operate today, as evidenced by the 57Fe and 182W heterogeneity of modern oceanic basalts. This project was funded by a NERC Consortia Grant (“Mantle Reservoirs, volumes and fluxes” NE/M000303/1) Article in Journal/Newspaper Greenland Apollo - University of Cambridge Repository Greenland |
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Open Polar |
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Apollo - University of Cambridge Repository |
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ftunivcam |
language |
English |
topic |
37 Earth Sciences 3703 Geochemistry 3705 Geology 3706 Geophysics 14 Life Below Water |
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37 Earth Sciences 3703 Geochemistry 3705 Geology 3706 Geophysics 14 Life Below Water Williams, Helen Matthews, Simon Rizo, Hanika Shorttle, O Iron isotopes trace primordial magma ocean cumulates melting in the Earth’s upper mantle |
topic_facet |
37 Earth Sciences 3703 Geochemistry 3705 Geology 3706 Geophysics 14 Life Below Water |
description |
The differentiation of the Earth ~ 4.5 Ga is believed to have culminated in magma ocean crystallization, crystal-liquid separation and the formation of mineralogically distinct mantle reservoirs. However, the magma ocean model remains difficult to validate due to the scarcity of geochemical tracers of lower mantle mineralogy. The Fe isotope compositions (57Fe) of ancient mafic rocks can be used to reconstruct the mineralogy of their mantle source regions. We present Fe isotope data for 3.7 Ga metabasalts from the Isua Supracrustal Belt (Greenland). The 57Fe signatures of these samples extend to values elevated relative to modern equivalents and define strong correlations with fluid-immobile trace elements and tungsten isotope anomalies (182W). Phase equilibria models demonstrate that these features can be explained by melting of a magma ocean cumulate component in the upper mantle. Similar processes may operate today, as evidenced by the 57Fe and 182W heterogeneity of modern oceanic basalts. This project was funded by a NERC Consortia Grant (“Mantle Reservoirs, volumes and fluxes” NE/M000303/1) |
format |
Article in Journal/Newspaper |
author |
Williams, Helen Matthews, Simon Rizo, Hanika Shorttle, O |
author_facet |
Williams, Helen Matthews, Simon Rizo, Hanika Shorttle, O |
author_sort |
Williams, Helen |
title |
Iron isotopes trace primordial magma ocean cumulates melting in the Earth’s upper mantle |
title_short |
Iron isotopes trace primordial magma ocean cumulates melting in the Earth’s upper mantle |
title_full |
Iron isotopes trace primordial magma ocean cumulates melting in the Earth’s upper mantle |
title_fullStr |
Iron isotopes trace primordial magma ocean cumulates melting in the Earth’s upper mantle |
title_full_unstemmed |
Iron isotopes trace primordial magma ocean cumulates melting in the Earth’s upper mantle |
title_sort |
iron isotopes trace primordial magma ocean cumulates melting in the earth’s upper mantle |
publisher |
American Association for the Advancement of Science |
publishDate |
2021 |
url |
https://www.repository.cam.ac.uk/handle/1810/319861 https://doi.org/10.17863/CAM.66986 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland |
genre_facet |
Greenland |
op_relation |
https://www.repository.cam.ac.uk/handle/1810/319861 doi:10.17863/CAM.66986 |
op_rights |
Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.17863/CAM.66986 |
_version_ |
1788061753696845824 |