Evidence for Low-Pressure Crustal Anatexis During the Northeast Atlantic Break-Up
While basaltic volcanism is dominant during rifting and continental breakup, felsic magmatism may be a significant component of some rift margins. During International Ocean Discovery Program (IODP) Expedition 396 on the continental margin of Norway, a graphite-garnet-cordierite bearing dacitic unit...
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AMER GEOPHYSICAL UNION
2024
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Online Access: | http://ir.qdio.ac.cn/handle/337002/185407 https://doi.org/10.1029/2023GC011413 |
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ftchinacasciocas:oai:ir.qdio.ac.cn:337002/185407 2024-09-15T18:25:22+00:00 Evidence for Low-Pressure Crustal Anatexis During the Northeast Atlantic Break-Up Morris, A. M. Lambart, S. Stearns, M. A. Bowman, J. R. Jones, M. T. Mohn, G. Andrews, G. Millett, J. Tegner, C. Chatterjee, S. Frieling, J. Guo, P. Jolley, D. W. Cunningham, E. H. Berndt, C. Planke, S. Alvarez Zarikian, C. A. Betlem, P. Brinkhuis, H. Christopoulou, M. Ferre, E. Filina, I. Y. Harper, D. T. Longman, J. Scherer, R. P. Varela, N. Xu, W. Yager, S. L. Agarwal, A. Clementi, V. J. 2024-07-01 http://ir.qdio.ac.cn/handle/337002/185407 https://doi.org/10.1029/2023GC011413 英语 eng AMER GEOPHYSICAL UNION GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS http://ir.qdio.ac.cn/handle/337002/185407 doi:10.1029/2023GC011413 crustal anatexis Mimir High IODP Site U1570 continental break-up NAIP Geochemistry & Geophysics EOCENE THERMAL MAXIMUM VORING TRANSFORM MARGIN CERRO-DEL-HOYAZO TRACE-ELEMENT BETIC CORDILLERA PERITECTIC GARNET PYROCLASTIC FLOWS MAGMATIC LIQUIDS ALMANDINE GARNET GRANITIC MAGMAS 期刊论文 2024 ftchinacasciocas https://doi.org/10.1029/2023GC011413 2024-08-29T23:34:26Z While basaltic volcanism is dominant during rifting and continental breakup, felsic magmatism may be a significant component of some rift margins. During International Ocean Discovery Program (IODP) Expedition 396 on the continental margin of Norway, a graphite-garnet-cordierite bearing dacitic unit (the Mimir dacite) was recovered in two holes within early Eocene sediments on Mimir High (Site U1570), a marginal high on the V & oslash;ring Transform Margin. Here, we present a comprehensive textural, petrological, and geochemical study of the Mimir dacite in order to assess its origin and discuss the geodynamic implications. The major mineral phases (garnet, cordierite, quartz, plagioclase, alkali feldspar) are hosted in a fresh rhyolitic, vesicular, glassy matrix that is locally mingled with sediments. The major element chemistry of garnet and cordierite, the presence of zircon inclusions with inherited cores, and thermobarometric calculations all support an upper crustal metapelitic origin. While most magma-rich margin models favor crustal anatexis in the lower crust, thermobarometric calculations performed here show that the Mimir dacite was produced at upper-crustal depths (<5 kbar, 18 km depth) and high temperature (750-800 degrees C) with up to 3 wt% water content. In situ U-Pb analyses on zircon inclusions give a magmatic crystallization age of 54.6 +/- 1.1 Ma, consistent with emplacement that post-dates the Paleocene-Eocene Thermal Maximum. Our results suggest that the opening of the Northeast Atlantic was associated with a phase of low-pressure, high-temperature crustal anatexis preceding the main phase of magmatism. Report Northeast Atlantic Institute of Oceanology, Chinese Academy of Sciences: IOCAS-IR Geochemistry, Geophysics, Geosystems 25 7 |
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Open Polar |
collection |
Institute of Oceanology, Chinese Academy of Sciences: IOCAS-IR |
op_collection_id |
ftchinacasciocas |
language |
English |
topic |
crustal anatexis Mimir High IODP Site U1570 continental break-up NAIP Geochemistry & Geophysics EOCENE THERMAL MAXIMUM VORING TRANSFORM MARGIN CERRO-DEL-HOYAZO TRACE-ELEMENT BETIC CORDILLERA PERITECTIC GARNET PYROCLASTIC FLOWS MAGMATIC LIQUIDS ALMANDINE GARNET GRANITIC MAGMAS |
spellingShingle |
crustal anatexis Mimir High IODP Site U1570 continental break-up NAIP Geochemistry & Geophysics EOCENE THERMAL MAXIMUM VORING TRANSFORM MARGIN CERRO-DEL-HOYAZO TRACE-ELEMENT BETIC CORDILLERA PERITECTIC GARNET PYROCLASTIC FLOWS MAGMATIC LIQUIDS ALMANDINE GARNET GRANITIC MAGMAS Morris, A. M. Lambart, S. Stearns, M. A. Bowman, J. R. Jones, M. T. Mohn, G. Andrews, G. Millett, J. Tegner, C. Chatterjee, S. Frieling, J. Guo, P. Jolley, D. W. Cunningham, E. H. Berndt, C. Planke, S. Alvarez Zarikian, C. A. Betlem, P. Brinkhuis, H. Christopoulou, M. Ferre, E. Filina, I. Y. Harper, D. T. Longman, J. Scherer, R. P. Varela, N. Xu, W. Yager, S. L. Agarwal, A. Clementi, V. J. Evidence for Low-Pressure Crustal Anatexis During the Northeast Atlantic Break-Up |
topic_facet |
crustal anatexis Mimir High IODP Site U1570 continental break-up NAIP Geochemistry & Geophysics EOCENE THERMAL MAXIMUM VORING TRANSFORM MARGIN CERRO-DEL-HOYAZO TRACE-ELEMENT BETIC CORDILLERA PERITECTIC GARNET PYROCLASTIC FLOWS MAGMATIC LIQUIDS ALMANDINE GARNET GRANITIC MAGMAS |
description |
While basaltic volcanism is dominant during rifting and continental breakup, felsic magmatism may be a significant component of some rift margins. During International Ocean Discovery Program (IODP) Expedition 396 on the continental margin of Norway, a graphite-garnet-cordierite bearing dacitic unit (the Mimir dacite) was recovered in two holes within early Eocene sediments on Mimir High (Site U1570), a marginal high on the V & oslash;ring Transform Margin. Here, we present a comprehensive textural, petrological, and geochemical study of the Mimir dacite in order to assess its origin and discuss the geodynamic implications. The major mineral phases (garnet, cordierite, quartz, plagioclase, alkali feldspar) are hosted in a fresh rhyolitic, vesicular, glassy matrix that is locally mingled with sediments. The major element chemistry of garnet and cordierite, the presence of zircon inclusions with inherited cores, and thermobarometric calculations all support an upper crustal metapelitic origin. While most magma-rich margin models favor crustal anatexis in the lower crust, thermobarometric calculations performed here show that the Mimir dacite was produced at upper-crustal depths (<5 kbar, 18 km depth) and high temperature (750-800 degrees C) with up to 3 wt% water content. In situ U-Pb analyses on zircon inclusions give a magmatic crystallization age of 54.6 +/- 1.1 Ma, consistent with emplacement that post-dates the Paleocene-Eocene Thermal Maximum. Our results suggest that the opening of the Northeast Atlantic was associated with a phase of low-pressure, high-temperature crustal anatexis preceding the main phase of magmatism. |
format |
Report |
author |
Morris, A. M. Lambart, S. Stearns, M. A. Bowman, J. R. Jones, M. T. Mohn, G. Andrews, G. Millett, J. Tegner, C. Chatterjee, S. Frieling, J. Guo, P. Jolley, D. W. Cunningham, E. H. Berndt, C. Planke, S. Alvarez Zarikian, C. A. Betlem, P. Brinkhuis, H. Christopoulou, M. Ferre, E. Filina, I. Y. Harper, D. T. Longman, J. Scherer, R. P. Varela, N. Xu, W. Yager, S. L. Agarwal, A. Clementi, V. J. |
author_facet |
Morris, A. M. Lambart, S. Stearns, M. A. Bowman, J. R. Jones, M. T. Mohn, G. Andrews, G. Millett, J. Tegner, C. Chatterjee, S. Frieling, J. Guo, P. Jolley, D. W. Cunningham, E. H. Berndt, C. Planke, S. Alvarez Zarikian, C. A. Betlem, P. Brinkhuis, H. Christopoulou, M. Ferre, E. Filina, I. Y. Harper, D. T. Longman, J. Scherer, R. P. Varela, N. Xu, W. Yager, S. L. Agarwal, A. Clementi, V. J. |
author_sort |
Morris, A. M. |
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 |
AMER GEOPHYSICAL UNION |
publishDate |
2024 |
url |
http://ir.qdio.ac.cn/handle/337002/185407 https://doi.org/10.1029/2023GC011413 |
genre |
Northeast Atlantic |
genre_facet |
Northeast Atlantic |
op_relation |
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS http://ir.qdio.ac.cn/handle/337002/185407 doi:10.1029/2023GC011413 |
op_doi |
https://doi.org/10.1029/2023GC011413 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
25 |
container_issue |
7 |
_version_ |
1810465868104073216 |