Titanium isotope constraints on the mafic sources and geodynamic origins of Archean crust
The timing and formation of Earth’s first continents during the Archean are subjects of significant debate. By examining titanium isotope variations in Archean Tonalite-Trondhjemite-Granodiorite (TTG) rocks and using advanced thermodynamic modelling, we can narrow down the processes involved and emp...
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ftfuberlin:oai:refubium.fu-berlin.de:fub188/43258 2024-05-19T07:41:22+00:00 Titanium isotope constraints on the mafic sources and geodynamic origins of Archean crust Hoare, L. Rzehak, L. J. A. Kommescher, S. Jansen, M. Rosing, M. T. Nagel, T. Millet, M. -A. Hoffmann, Jörg Elis Fonseca, R. O. C. 2023 6 Seiten application/pdf https://refubium.fu-berlin.de/handle/fub188/43258 https://doi.org/10.17169/refubium-42974 https://doi.org/10.7185/geochemlet.2342 eng eng https://refubium.fu-berlin.de/handle/fub188/43258 http://dx.doi.org/10.17169/refubium-42974 doi:10.7185/geochemlet.2342 https://creativecommons.org/licenses/by-nc-nd/4.0/ titanium isotopes continental crust Archean geodynamics subduction ddc:550 doc-type:article 2023 ftfuberlin https://doi.org/10.17169/refubium-4297410.7185/geochemlet.2342 2024-04-24T00:16:39Z The timing and formation of Earth’s first continents during the Archean are subjects of significant debate. By examining titanium isotope variations in Archean Tonalite-Trondhjemite-Granodiorite (TTG) rocks and using advanced thermodynamic modelling, we can narrow down the processes involved and emphasise the role of mafic precursor compositions. In our study of Eoarchean Isua metabasalts and Itsaq tonalites in southern West Greenland, we observed a pattern of increasing Ti isotope enrichment with higher SiO2 content, resembling the compositions found in modern subduction zone rocks. Our modelling suggests that the Ti isotope variations in TTGs can be best explained by a combination of partial melting of low TiO2 metabasalts and subsequent crystallisation of tonalitic magmas, resulting in heavier Ti isotopes. This means that Ti isotopes help us distinguish the contributions of various mafic sources and fractional crystallisation during TTG formation. In the case of Itsaq tonalites and many other Eoarchean TTGs, low TiO2 tholeiitic metabasalts with arc-like characteristics likely represent the mafic source rocks, suggesting the formation of some of Earth’s earliest continental crust within a proto-subduction zone setting. Article in Journal/Newspaper Greenland Freie Universität Berlin: Refubium (FU Berlin) |
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Open Polar |
collection |
Freie Universität Berlin: Refubium (FU Berlin) |
op_collection_id |
ftfuberlin |
language |
English |
topic |
titanium isotopes continental crust Archean geodynamics subduction ddc:550 |
spellingShingle |
titanium isotopes continental crust Archean geodynamics subduction ddc:550 Hoare, L. Rzehak, L. J. A. Kommescher, S. Jansen, M. Rosing, M. T. Nagel, T. Millet, M. -A. Hoffmann, Jörg Elis Fonseca, R. O. C. Titanium isotope constraints on the mafic sources and geodynamic origins of Archean crust |
topic_facet |
titanium isotopes continental crust Archean geodynamics subduction ddc:550 |
description |
The timing and formation of Earth’s first continents during the Archean are subjects of significant debate. By examining titanium isotope variations in Archean Tonalite-Trondhjemite-Granodiorite (TTG) rocks and using advanced thermodynamic modelling, we can narrow down the processes involved and emphasise the role of mafic precursor compositions. In our study of Eoarchean Isua metabasalts and Itsaq tonalites in southern West Greenland, we observed a pattern of increasing Ti isotope enrichment with higher SiO2 content, resembling the compositions found in modern subduction zone rocks. Our modelling suggests that the Ti isotope variations in TTGs can be best explained by a combination of partial melting of low TiO2 metabasalts and subsequent crystallisation of tonalitic magmas, resulting in heavier Ti isotopes. This means that Ti isotopes help us distinguish the contributions of various mafic sources and fractional crystallisation during TTG formation. In the case of Itsaq tonalites and many other Eoarchean TTGs, low TiO2 tholeiitic metabasalts with arc-like characteristics likely represent the mafic source rocks, suggesting the formation of some of Earth’s earliest continental crust within a proto-subduction zone setting. |
format |
Article in Journal/Newspaper |
author |
Hoare, L. Rzehak, L. J. A. Kommescher, S. Jansen, M. Rosing, M. T. Nagel, T. Millet, M. -A. Hoffmann, Jörg Elis Fonseca, R. O. C. |
author_facet |
Hoare, L. Rzehak, L. J. A. Kommescher, S. Jansen, M. Rosing, M. T. Nagel, T. Millet, M. -A. Hoffmann, Jörg Elis Fonseca, R. O. C. |
author_sort |
Hoare, L. |
title |
Titanium isotope constraints on the mafic sources and geodynamic origins of Archean crust |
title_short |
Titanium isotope constraints on the mafic sources and geodynamic origins of Archean crust |
title_full |
Titanium isotope constraints on the mafic sources and geodynamic origins of Archean crust |
title_fullStr |
Titanium isotope constraints on the mafic sources and geodynamic origins of Archean crust |
title_full_unstemmed |
Titanium isotope constraints on the mafic sources and geodynamic origins of Archean crust |
title_sort |
titanium isotope constraints on the mafic sources and geodynamic origins of archean crust |
publishDate |
2023 |
url |
https://refubium.fu-berlin.de/handle/fub188/43258 https://doi.org/10.17169/refubium-42974 https://doi.org/10.7185/geochemlet.2342 |
genre |
Greenland |
genre_facet |
Greenland |
op_relation |
https://refubium.fu-berlin.de/handle/fub188/43258 http://dx.doi.org/10.17169/refubium-42974 doi:10.7185/geochemlet.2342 |
op_rights |
https://creativecommons.org/licenses/by-nc-nd/4.0/ |
op_doi |
https://doi.org/10.17169/refubium-4297410.7185/geochemlet.2342 |
_version_ |
1799480965590941696 |