Evidence for Low-Pressure Crustal Anatexis During the Northeast Atlantic Break-up
While basaltic volcanism is dominate during rifting and continental breakup, felsic magmatism may also comprise important components of some rift margins. During International Ocean Discovery Program (IODP) Expedition 396 on the continental margin of Norway, a graphite-garnet-cordierite bearing daci...
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2023
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Online Access: | http://dx.doi.org/10.22541/essoar.170365241.10187842/v1 |
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crwinnower:10.22541/essoar.170365241.10187842/v1 2024-06-02T08:11:33+00:00 Evidence for Low-Pressure Crustal Anatexis During the Northeast Atlantic Break-up Morris, Ashley Mae Lambart, Sarah Stearns, Michael Andrew Bowman, John Jones, Morgan T MOHN, Geoffroy Andrews, Graham Millet, John Michael Tegner, Christian Chatterjee, Sayantani Frieling, Joost Guo, Pengyuan Berndt, Christian Planke, Sverre Alvarez-Zarikian, Carlos Andres Betlem, Peter Brinkhuis, Henk Christopoulou, Marilena Ferré, Eric C. Filina, Irina Harper, Dustin T. Jolley, David Longman, Jack Scherer, Reed Varela, Natalia Xu, Weimu Yager, Stacy L Agarwal, Amar Clementi, Vincent J 2023 http://dx.doi.org/10.22541/essoar.170365241.10187842/v1 unknown Authorea, Inc. posted-content 2023 crwinnower https://doi.org/10.22541/essoar.170365241.10187842/v1 2024-05-07T14:19:21Z While basaltic volcanism is dominate during rifting and continental breakup, felsic magmatism may also comprise important components of some rift margins. During International Ocean Discovery Program (IODP) Expedition 396 on the continental margin of Norway, a graphite-garnet-cordierite bearing dacitic, pyroclastic unit was recovered within early Eocene sediments on Mimir High (Site U1570), a marginal high on the Vøring transform margin. Here, we present a comprehensive textural, mineralogical, and petrological study of the dacite in order to assess its melting origin and emplacement. The major mineral phases (garnet, cordierite, quartz, plagioclase, alkali feldspar) are hosted in a fresh rhyolitic, highly vesicular, glassy matrix, locally mingled with sediments. The xenocrystic major element chemistry of garnet and cordierite, the presence of zircon inclusions with inherited cores, and thermobarometric calculations all support a crustal metapelite origin. While most magma-rich margin models favor crustal anatexis in the lower crust, thermobarometric calculations performed here show that the dacite was produced at upper-crustal depths (< 5 kbar) and high temperature (750–800 °C) with up to 3 wt% water content. In situ U-Pb analyses on zircon inclusions give a magmatic age of 54.6 ± 1.1 Ma, revealing the emplacement of the dacite post-dates the Paleocene-Eocene Thermal Maximum (PETM). Our results suggest that the opening of the North Atlantic was associated with a phase of low-pressure, high-temperature crustal melting at the onset of the main phase of magmatism. Other/Unknown Material North Atlantic Northeast Atlantic The Winnower Norway |
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The Winnower |
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description |
While basaltic volcanism is dominate during rifting and continental breakup, felsic magmatism may also comprise important components of some rift margins. During International Ocean Discovery Program (IODP) Expedition 396 on the continental margin of Norway, a graphite-garnet-cordierite bearing dacitic, pyroclastic unit was recovered within early Eocene sediments on Mimir High (Site U1570), a marginal high on the Vøring transform margin. Here, we present a comprehensive textural, mineralogical, and petrological study of the dacite in order to assess its melting origin and emplacement. The major mineral phases (garnet, cordierite, quartz, plagioclase, alkali feldspar) are hosted in a fresh rhyolitic, highly vesicular, glassy matrix, locally mingled with sediments. The xenocrystic major element chemistry of garnet and cordierite, the presence of zircon inclusions with inherited cores, and thermobarometric calculations all support a crustal metapelite origin. While most magma-rich margin models favor crustal anatexis in the lower crust, thermobarometric calculations performed here show that the dacite was produced at upper-crustal depths (< 5 kbar) and high temperature (750–800 °C) with up to 3 wt% water content. In situ U-Pb analyses on zircon inclusions give a magmatic age of 54.6 ± 1.1 Ma, revealing the emplacement of the dacite post-dates the Paleocene-Eocene Thermal Maximum (PETM). Our results suggest that the opening of the North Atlantic was associated with a phase of low-pressure, high-temperature crustal melting at the onset of the main phase of magmatism. |
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Other/Unknown Material |
author |
Morris, Ashley Mae Lambart, Sarah Stearns, Michael Andrew Bowman, John Jones, Morgan T MOHN, Geoffroy Andrews, Graham Millet, John Michael Tegner, Christian Chatterjee, Sayantani Frieling, Joost Guo, Pengyuan Berndt, Christian Planke, Sverre Alvarez-Zarikian, Carlos Andres Betlem, Peter Brinkhuis, Henk Christopoulou, Marilena Ferré, Eric C. Filina, Irina Harper, Dustin T. Jolley, David Longman, Jack Scherer, Reed Varela, Natalia Xu, Weimu Yager, Stacy L Agarwal, Amar Clementi, Vincent J |
spellingShingle |
Morris, Ashley Mae Lambart, Sarah Stearns, Michael Andrew Bowman, John Jones, Morgan T MOHN, Geoffroy Andrews, Graham Millet, John Michael Tegner, Christian Chatterjee, Sayantani Frieling, Joost Guo, Pengyuan Berndt, Christian Planke, Sverre Alvarez-Zarikian, Carlos Andres Betlem, Peter Brinkhuis, Henk Christopoulou, Marilena Ferré, Eric C. Filina, Irina Harper, Dustin T. Jolley, David Longman, Jack Scherer, Reed Varela, Natalia Xu, Weimu Yager, Stacy L Agarwal, Amar Clementi, Vincent J Evidence for Low-Pressure Crustal Anatexis During the Northeast Atlantic Break-up |
author_facet |
Morris, Ashley Mae Lambart, Sarah Stearns, Michael Andrew Bowman, John Jones, Morgan T MOHN, Geoffroy Andrews, Graham Millet, John Michael Tegner, Christian Chatterjee, Sayantani Frieling, Joost Guo, Pengyuan Berndt, Christian Planke, Sverre Alvarez-Zarikian, Carlos Andres Betlem, Peter Brinkhuis, Henk Christopoulou, Marilena Ferré, Eric C. Filina, Irina Harper, Dustin T. Jolley, David Longman, Jack Scherer, Reed Varela, Natalia Xu, Weimu Yager, Stacy L Agarwal, Amar Clementi, Vincent J |
author_sort |
Morris, Ashley Mae |
title |
Evidence for Low-Pressure Crustal Anatexis During the Northeast Atlantic Break-up |
title_short |
Evidence for Low-Pressure Crustal Anatexis During the Northeast Atlantic Break-up |
title_full |
Evidence for Low-Pressure Crustal Anatexis During the Northeast Atlantic Break-up |
title_fullStr |
Evidence for Low-Pressure Crustal Anatexis During the Northeast Atlantic Break-up |
title_full_unstemmed |
Evidence for Low-Pressure Crustal Anatexis During the Northeast Atlantic Break-up |
title_sort |
evidence for low-pressure crustal anatexis during the northeast atlantic break-up |
publisher |
Authorea, Inc. |
publishDate |
2023 |
url |
http://dx.doi.org/10.22541/essoar.170365241.10187842/v1 |
geographic |
Norway |
geographic_facet |
Norway |
genre |
North Atlantic Northeast Atlantic |
genre_facet |
North Atlantic Northeast Atlantic |
op_doi |
https://doi.org/10.22541/essoar.170365241.10187842/v1 |
_version_ |
1800757727626002432 |