The distribution and generation of carbonatites
<jats:title>Abstract</jats:title> <jats:p>The physio-chemical framework that generates carbonatites and, ultimately, the associated rare earth element deposits remains contentious. This primarily reflects the diverse tectonic settings in which carbonatites occur: large igneous prov...
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ftunivcam:oai:www.repository.cam.ac.uk:1810/369239 2024-09-30T14:35:58+00:00 The distribution and generation of carbonatites Gibson, S McKenzie, D Lebedev, S 2024-09-01 application/pdf https://www.repository.cam.ac.uk/handle/1810/369239 https://doi.org/10.17863/CAM.109124 eng eng Geological Society of America Department of Earth Sciences http://dx.doi.org/10.1130/g52141.1 Geology https://www.repository.cam.ac.uk/handle/1810/369239 https://doi.org/10.17863/CAM.109124 Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ 37 Earth Sciences 3703 Geochemistry 3705 Geology 3706 Geophysics Article 2024 ftunivcam https://doi.org/10.17863/CAM.109124 2024-09-11T00:08:47Z <jats:title>Abstract</jats:title> <jats:p>The physio-chemical framework that generates carbonatites and, ultimately, the associated rare earth element deposits remains contentious. This primarily reflects the diverse tectonic settings in which carbonatites occur: large igneous provinces, continental rifts and major extensional terranes, syn- to post-collisional settings, or ocean islands. There is, however, a broad consensus that carbonatites (or their parental melts) originate in the mantle. These exotic melts have small volumes that make them ideal probes of conditions in their underlying source regions. We combine the carbonatite locations with global maps of lithospheric thickness, derived from seismic tomography, and show that post-Neoproterozoic carbonatites occur preferentially above the margins of thick cratonic lithosphere (e.g., adjacent to the South Atlantic and Indian Oceans or in North America, Greenland, and Asia) and where once thick lithosphere has undergone stretching (e.g., eastern Asia). Our thermal modeling reveals that lateral and vertical heat conduction on rifted craton margins, or rapid stretching of cratonic lithosphere, can mobilize carbonated peridotite at the temperatures (950–1250 °C) and pressures (2–3 GPa) required to form primary carbonatites or their parental alkali silicate melts. Importantly, our models show that heat conduction from upwelling mantle plumes or ambient mantle on rifted cratonic margins may sufficiently modify the temperature of the lithospheric mantle to cause melting of carbonated peridotite, settling the long-standing debate on the role of rifting and heating in the generation of carbonatites.</jats:p> Article in Journal/Newspaper Greenland Apollo - University of Cambridge Repository Greenland Indian |
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English |
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37 Earth Sciences 3703 Geochemistry 3705 Geology 3706 Geophysics |
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37 Earth Sciences 3703 Geochemistry 3705 Geology 3706 Geophysics Gibson, S McKenzie, D Lebedev, S The distribution and generation of carbonatites |
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37 Earth Sciences 3703 Geochemistry 3705 Geology 3706 Geophysics |
description |
<jats:title>Abstract</jats:title> <jats:p>The physio-chemical framework that generates carbonatites and, ultimately, the associated rare earth element deposits remains contentious. This primarily reflects the diverse tectonic settings in which carbonatites occur: large igneous provinces, continental rifts and major extensional terranes, syn- to post-collisional settings, or ocean islands. There is, however, a broad consensus that carbonatites (or their parental melts) originate in the mantle. These exotic melts have small volumes that make them ideal probes of conditions in their underlying source regions. We combine the carbonatite locations with global maps of lithospheric thickness, derived from seismic tomography, and show that post-Neoproterozoic carbonatites occur preferentially above the margins of thick cratonic lithosphere (e.g., adjacent to the South Atlantic and Indian Oceans or in North America, Greenland, and Asia) and where once thick lithosphere has undergone stretching (e.g., eastern Asia). Our thermal modeling reveals that lateral and vertical heat conduction on rifted craton margins, or rapid stretching of cratonic lithosphere, can mobilize carbonated peridotite at the temperatures (950–1250 °C) and pressures (2–3 GPa) required to form primary carbonatites or their parental alkali silicate melts. Importantly, our models show that heat conduction from upwelling mantle plumes or ambient mantle on rifted cratonic margins may sufficiently modify the temperature of the lithospheric mantle to cause melting of carbonated peridotite, settling the long-standing debate on the role of rifting and heating in the generation of carbonatites.</jats:p> |
format |
Article in Journal/Newspaper |
author |
Gibson, S McKenzie, D Lebedev, S |
author_facet |
Gibson, S McKenzie, D Lebedev, S |
author_sort |
Gibson, S |
title |
The distribution and generation of carbonatites |
title_short |
The distribution and generation of carbonatites |
title_full |
The distribution and generation of carbonatites |
title_fullStr |
The distribution and generation of carbonatites |
title_full_unstemmed |
The distribution and generation of carbonatites |
title_sort |
distribution and generation of carbonatites |
publisher |
Geological Society of America |
publishDate |
2024 |
url |
https://www.repository.cam.ac.uk/handle/1810/369239 https://doi.org/10.17863/CAM.109124 |
geographic |
Greenland Indian |
geographic_facet |
Greenland Indian |
genre |
Greenland |
genre_facet |
Greenland |
op_relation |
https://www.repository.cam.ac.uk/handle/1810/369239 https://doi.org/10.17863/CAM.109124 |
op_rights |
Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.17863/CAM.109124 |
_version_ |
1811639165190668288 |