Mantle temperature control on composition of arc magmas along the Central Kamchatka Depression
Abundant volcanism in the Central Kamchatka Depression (CKD) adjacent to the Kamchatka–Aleutian Arc junction occurs where the Pacific slab edge is subducting beneath Kamchatka. Here we summarize published data on CKD rocks and demonstrate a systematic south-to-north change of their compositions from...
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Geological Society of America
2008
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Online Access: | https://authors.library.caltech.edu/75912/ https://authors.library.caltech.edu/75912/2/2008128.pdf https://resolver.caltech.edu/CaltechAUTHORS:20170408-140358225 |
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ftcaltechauth:oai:authors.library.caltech.edu:75912 2023-05-15T16:58:42+02:00 Mantle temperature control on composition of arc magmas along the Central Kamchatka Depression Portnyagin, Maxim Manea, Vlad Constantin 2008-07 application/pdf https://authors.library.caltech.edu/75912/ https://authors.library.caltech.edu/75912/2/2008128.pdf https://resolver.caltech.edu/CaltechAUTHORS:20170408-140358225 en eng Geological Society of America https://authors.library.caltech.edu/75912/2/2008128.pdf Portnyagin, Maxim and Manea, Vlad Constantin (2008) Mantle temperature control on composition of arc magmas along the Central Kamchatka Depression. Geology, 36 (7). pp. 519-522. ISSN 0091-7613. doi:10.1130/G24636A.1. https://resolver.caltech.edu/CaltechAUTHORS:20170408-140358225 <https://resolver.caltech.edu/CaltechAUTHORS:20170408-140358225> other Article PeerReviewed 2008 ftcaltechauth https://doi.org/10.1130/G24636A.1 2021-11-18T18:41:31Z Abundant volcanism in the Central Kamchatka Depression (CKD) adjacent to the Kamchatka–Aleutian Arc junction occurs where the Pacific slab edge is subducting beneath Kamchatka. Here we summarize published data on CKD rocks and demonstrate a systematic south-to-north change of their compositions from moderately fractionated basalt-andesite tholeiitic series to highly fractionated basalt-rhyolite calc-alkaline series including high-magnesian andesites near the slab edge. Localized slab melting at the slab edge cannot explain these regional geochemical variations. Instead, we propose that the thermal state of the mantle wedge can be the key factor governing the composition of CKD magmas. We integrate the results from petrology and numeric modeling to demonstrate the northward decrease of the mantle wedge temperatures beneath CKD volcanoes, which correlates with decreasing slab dip, length of mantle columns, and magma flux. We envision two petrogenetic models, which relate the composition of erupted magmas to the subduction parameters beneath the CKD. The first model suggests that mantle temperature governs melt-peridotite equilibria and favors generation of andesitic primary melts in cold mantle regions above the shallowly subducting Pacific slab edge. Alternatively, mantle temperature may control magmatic productivity along the CKD, which decreases sharply toward the slab edge and thus allows more extensive magma fractionation deeper in the crust and mixing of highly evolved and mantle-derived magmas to generate Si-rich “primitive” magmas. These results point to a possible casual link between deep mantle and shallow crustal magmatic processes. Similar effects of mantle temperature on the composition and productivity of arc magmatism are expected elsewhere, particularly in volcanic regions associated with significant slab dip variation along the arc. Article in Journal/Newspaper Kamchatka Caltech Authors (California Institute of Technology) Pacific Geology 36 7 519 |
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Open Polar |
collection |
Caltech Authors (California Institute of Technology) |
op_collection_id |
ftcaltechauth |
language |
English |
description |
Abundant volcanism in the Central Kamchatka Depression (CKD) adjacent to the Kamchatka–Aleutian Arc junction occurs where the Pacific slab edge is subducting beneath Kamchatka. Here we summarize published data on CKD rocks and demonstrate a systematic south-to-north change of their compositions from moderately fractionated basalt-andesite tholeiitic series to highly fractionated basalt-rhyolite calc-alkaline series including high-magnesian andesites near the slab edge. Localized slab melting at the slab edge cannot explain these regional geochemical variations. Instead, we propose that the thermal state of the mantle wedge can be the key factor governing the composition of CKD magmas. We integrate the results from petrology and numeric modeling to demonstrate the northward decrease of the mantle wedge temperatures beneath CKD volcanoes, which correlates with decreasing slab dip, length of mantle columns, and magma flux. We envision two petrogenetic models, which relate the composition of erupted magmas to the subduction parameters beneath the CKD. The first model suggests that mantle temperature governs melt-peridotite equilibria and favors generation of andesitic primary melts in cold mantle regions above the shallowly subducting Pacific slab edge. Alternatively, mantle temperature may control magmatic productivity along the CKD, which decreases sharply toward the slab edge and thus allows more extensive magma fractionation deeper in the crust and mixing of highly evolved and mantle-derived magmas to generate Si-rich “primitive” magmas. These results point to a possible casual link between deep mantle and shallow crustal magmatic processes. Similar effects of mantle temperature on the composition and productivity of arc magmatism are expected elsewhere, particularly in volcanic regions associated with significant slab dip variation along the arc. |
format |
Article in Journal/Newspaper |
author |
Portnyagin, Maxim Manea, Vlad Constantin |
spellingShingle |
Portnyagin, Maxim Manea, Vlad Constantin Mantle temperature control on composition of arc magmas along the Central Kamchatka Depression |
author_facet |
Portnyagin, Maxim Manea, Vlad Constantin |
author_sort |
Portnyagin, Maxim |
title |
Mantle temperature control on composition of arc magmas along the Central Kamchatka Depression |
title_short |
Mantle temperature control on composition of arc magmas along the Central Kamchatka Depression |
title_full |
Mantle temperature control on composition of arc magmas along the Central Kamchatka Depression |
title_fullStr |
Mantle temperature control on composition of arc magmas along the Central Kamchatka Depression |
title_full_unstemmed |
Mantle temperature control on composition of arc magmas along the Central Kamchatka Depression |
title_sort |
mantle temperature control on composition of arc magmas along the central kamchatka depression |
publisher |
Geological Society of America |
publishDate |
2008 |
url |
https://authors.library.caltech.edu/75912/ https://authors.library.caltech.edu/75912/2/2008128.pdf https://resolver.caltech.edu/CaltechAUTHORS:20170408-140358225 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
Kamchatka |
genre_facet |
Kamchatka |
op_relation |
https://authors.library.caltech.edu/75912/2/2008128.pdf Portnyagin, Maxim and Manea, Vlad Constantin (2008) Mantle temperature control on composition of arc magmas along the Central Kamchatka Depression. Geology, 36 (7). pp. 519-522. ISSN 0091-7613. doi:10.1130/G24636A.1. https://resolver.caltech.edu/CaltechAUTHORS:20170408-140358225 <https://resolver.caltech.edu/CaltechAUTHORS:20170408-140358225> |
op_rights |
other |
op_doi |
https://doi.org/10.1130/G24636A.1 |
container_title |
Geology |
container_volume |
36 |
container_issue |
7 |
container_start_page |
519 |
_version_ |
1766050774954016768 |