Geochemical evidence for a widespread mantle re-enrichment 3.2 billion years ago: implications for global-scale plate tectonics
Progressive mantle melting during the Earth’s earliest evolution led to the formation of a depleted mantle and a continental crust enriched in highly incompatible elements. Re-enrichment of Earth’s mantle can occur when continental crustal materials begin to founder into the mantle by either subduct...
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| Format: | Journal Article |
| Language: | English |
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NATURE PORTFOLIO
2020
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| Online Access: | http://purl.org/au-research/grants/arc/FL150100133 http://hdl.handle.net/20.500.11937/90608 |
| _version_ | 1848765401163366400 |
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| author | Gamal El Dien, Hamed Doucet, Luc Murphy, J. Brendan Li, Zheng-Xiang |
| author_facet | Gamal El Dien, Hamed Doucet, Luc Murphy, J. Brendan Li, Zheng-Xiang |
| author_sort | Gamal El Dien, Hamed |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Progressive mantle melting during the Earth’s earliest evolution led to the formation of a depleted mantle and a continental crust enriched in highly incompatible elements. Re-enrichment of Earth’s mantle can occur when continental crustal materials begin to founder into the mantle by either subduction or, to a lesser degree, by delamination processes, profoundly affecting the mantle’s trace element and volatile compositions. Deciphering when mantle re-enrichment/refertilization became a global-scale process would reveal the onset of efficient mass transfer of crust to the mantle and potentially when plate tectonic processes became operative on a global-scale. Here we document the onset of mantle re-enrichment/refertilization by comparing the abundances of petrogenetically significant isotopic values and key ratios of highly incompatible elements compared to lithophile elements in Archean to Early-Proterozoic mantle-derived melts (i.e., basalts and komatiites). Basalts and komatiites both record a rapid-change in mantle chemistry around 3.2 billion years ago (Ga) signifying a fundamental change in Earth geodynamics. This rapid-change is recorded in Nd isotopes and in key trace element ratios that reflect a fundamental shift in the balance between fluid-mobile and incompatible elements (i.e., Ba/La, Ba/Nb, U/Nb, Pb/Nd and Pb/Ce) in basaltic and komatiitic rocks. These geochemical proxies display a significant increase in magnitude and variability after ~3.2 Ga. We hypothesize that rapid increases in mantle heterogeneity indicate the recycling of supracrustal materials back into Earth’s mantle via subduction. Our new observations thus point to a ≥ 3.2 Ga onset of global subduction processes via plate tectonics. |
| first_indexed | 2025-11-14T11:34:40Z |
| format | Journal Article |
| id | curtin-20.500.11937-90608 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T11:34:40Z |
| publishDate | 2020 |
| publisher | NATURE PORTFOLIO |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-906082023-03-23T03:15:51Z Geochemical evidence for a widespread mantle re-enrichment 3.2 billion years ago: implications for global-scale plate tectonics Gamal El Dien, Hamed Doucet, Luc Murphy, J. Brendan Li, Zheng-Xiang Science & Technology Multidisciplinary Sciences Science & Technology - Other Topics BARBERTON GREENSTONE-BELT CONTINENTAL-CRUST ARCHEAN TECTONICS OCEANIC BASALTS HADEAN MANTLE ND EVOLUTION GROWTH SUBDUCTION HF Progressive mantle melting during the Earth’s earliest evolution led to the formation of a depleted mantle and a continental crust enriched in highly incompatible elements. Re-enrichment of Earth’s mantle can occur when continental crustal materials begin to founder into the mantle by either subduction or, to a lesser degree, by delamination processes, profoundly affecting the mantle’s trace element and volatile compositions. Deciphering when mantle re-enrichment/refertilization became a global-scale process would reveal the onset of efficient mass transfer of crust to the mantle and potentially when plate tectonic processes became operative on a global-scale. Here we document the onset of mantle re-enrichment/refertilization by comparing the abundances of petrogenetically significant isotopic values and key ratios of highly incompatible elements compared to lithophile elements in Archean to Early-Proterozoic mantle-derived melts (i.e., basalts and komatiites). Basalts and komatiites both record a rapid-change in mantle chemistry around 3.2 billion years ago (Ga) signifying a fundamental change in Earth geodynamics. This rapid-change is recorded in Nd isotopes and in key trace element ratios that reflect a fundamental shift in the balance between fluid-mobile and incompatible elements (i.e., Ba/La, Ba/Nb, U/Nb, Pb/Nd and Pb/Ce) in basaltic and komatiitic rocks. These geochemical proxies display a significant increase in magnitude and variability after ~3.2 Ga. We hypothesize that rapid increases in mantle heterogeneity indicate the recycling of supracrustal materials back into Earth’s mantle via subduction. Our new observations thus point to a ≥ 3.2 Ga onset of global subduction processes via plate tectonics. 2020 Journal Article http://hdl.handle.net/20.500.11937/90608 10.1038/s41598-020-66324-y English http://purl.org/au-research/grants/arc/FL150100133 http://creativecommons.org/licenses/by/4.0/ NATURE PORTFOLIO fulltext |
| spellingShingle | Science & Technology Multidisciplinary Sciences Science & Technology - Other Topics BARBERTON GREENSTONE-BELT CONTINENTAL-CRUST ARCHEAN TECTONICS OCEANIC BASALTS HADEAN MANTLE ND EVOLUTION GROWTH SUBDUCTION HF Gamal El Dien, Hamed Doucet, Luc Murphy, J. Brendan Li, Zheng-Xiang Geochemical evidence for a widespread mantle re-enrichment 3.2 billion years ago: implications for global-scale plate tectonics |
| title | Geochemical evidence for a widespread mantle re-enrichment 3.2 billion years ago: implications for global-scale plate tectonics |
| title_full | Geochemical evidence for a widespread mantle re-enrichment 3.2 billion years ago: implications for global-scale plate tectonics |
| title_fullStr | Geochemical evidence for a widespread mantle re-enrichment 3.2 billion years ago: implications for global-scale plate tectonics |
| title_full_unstemmed | Geochemical evidence for a widespread mantle re-enrichment 3.2 billion years ago: implications for global-scale plate tectonics |
| title_short | Geochemical evidence for a widespread mantle re-enrichment 3.2 billion years ago: implications for global-scale plate tectonics |
| title_sort | geochemical evidence for a widespread mantle re-enrichment 3.2 billion years ago: implications for global-scale plate tectonics |
| topic | Science & Technology Multidisciplinary Sciences Science & Technology - Other Topics BARBERTON GREENSTONE-BELT CONTINENTAL-CRUST ARCHEAN TECTONICS OCEANIC BASALTS HADEAN MANTLE ND EVOLUTION GROWTH SUBDUCTION HF |
| url | http://purl.org/au-research/grants/arc/FL150100133 http://hdl.handle.net/20.500.11937/90608 |