On the time scales of magma genesis, melt evolution, crystal growth rates and magma degassing in the erebus volcano magmatic system using the 238 U, 235 U and 232 Th decay series
We investigate the time scales of magma genesis, melt evolution, crystal growth rates and magma degassing in the Erebus volcano magmatic system using measurements of 238 U- 230 Th- 226 Ra- 210 Pb- 210 Po, 232 Th- 228 Ra- 228 Th and 235 U- 231 Pa- 227 Ac. These are the first measurements of 231 Pa- 2...
Published in: | Journal of Petrology |
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2013
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Online Access: | https://hdl.handle.net/1983/1d071f5c-baf0-4f6d-8f02-0e835c46c403 https://research-information.bris.ac.uk/en/publications/1d071f5c-baf0-4f6d-8f02-0e835c46c403 https://doi.org/10.1093/petrology/egs068 http://www.scopus.com/inward/record.url?scp=84872778367&partnerID=8YFLogxK |
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ftubristolcris:oai:research-information.bris.ac.uk:publications/1d071f5c-baf0-4f6d-8f02-0e835c46c403 2024-01-28T10:00:10+01:00 On the time scales of magma genesis, melt evolution, crystal growth rates and magma degassing in the erebus volcano magmatic system using the 238 U, 235 U and 232 Th decay series Sims, Kenneth W W Pichat, Sylvain Reagan, Mark K. Kyle, Philip R. Dulaiova, Henrietta Dunbar, Nelia W. Prytulak, Julie Sawyer, Georgina Layne, Graham D. Blichert-Toft, Janne Gauthier, Pierre J. Charette, Matthew A. Elliott, Timothy R. Elliott, Tim 2013-02-01 https://hdl.handle.net/1983/1d071f5c-baf0-4f6d-8f02-0e835c46c403 https://research-information.bris.ac.uk/en/publications/1d071f5c-baf0-4f6d-8f02-0e835c46c403 https://doi.org/10.1093/petrology/egs068 http://www.scopus.com/inward/record.url?scp=84872778367&partnerID=8YFLogxK eng eng info:eu-repo/semantics/restrictedAccess Sims , K W W , Pichat , S , Reagan , M K , Kyle , P R , Dulaiova , H , Dunbar , N W , Prytulak , J , Sawyer , G , Layne , G D , Blichert-Toft , J , Gauthier , P J , Charette , M A , Elliott , T R & Elliott , T 2013 , ' On the time scales of magma genesis, melt evolution, crystal growth rates and magma degassing in the erebus volcano magmatic system using the 238 U, 235 U and 232 Th decay series ' , Journal of Petrology , vol. 54 , no. 2 , pp. 235-271 . https://doi.org/10.1093/petrology/egs068 Antarctica Erebus volcano HIMU Magma chamber residence time Magma degassing Open-system crystallization U-series isotopes article 2013 ftubristolcris https://doi.org/10.1093/petrology/egs068 2024-01-04T23:44:57Z We investigate the time scales of magma genesis, melt evolution, crystal growth rates and magma degassing in the Erebus volcano magmatic system using measurements of 238 U- 230 Th- 226 Ra- 210 Pb- 210 Po, 232 Th- 228 Ra- 228 Th and 235 U- 231 Pa- 227 Ac. These are the first measurements of 231 Pa- 227 Ac in volcanic samples and represent the first set of data in a volcanic system to examine the entire suite of relevant 238 U, 235 U and 232 Th decay series nuclides. Our sample suite consists of 22 phonolite volcanic bombs, erupted between 1972 and 2005, and five anorthoclase megacrysts separated from bombs erupted in 1984, 1989, 1993, 2004 and 2005. The 238 U- 230 Th, 230 Th- 226 Ra and 235 U- 231 Pa systems are uniform over the 34 years examined. The anorthoclase megacrysts and phonolite glasses show complementary 226 Ra/ 230 Th disequilibria with ( 226 Ra/ 230 Th) ~40 in the anorthoclase and ~0·75 in the phonolite glass. In all samples, ( 210 Pb/ 226 Ra) is in radioactive equilibrium for both phases. In two phonolite glass samples ( 227 Ac/ 231 Pa) is unity. For the phonolite glasses ( 228 Ra/ 232 Th) is in equilibrium, whereas in the anorthoclase megacrysts it is significantly greater than unity. Instantaneous crystal fractionation, with magma residence times greater than 100 years and less than 10 kyr, can account for the measured 238 U- 230 Th- 226 Ra- 210 Pb and 235 U- 231 Pa- 227 Ac. However, the significant 228 Ra/ 232 Th disequilibria in the anorthoclase megacrysts preclude this simple interpretation. To account for this apparent discrepancy we therefore developed an open-system, continuous crystallization model that incorporates both nuclide ingrowth and decay during crystallization. This open-system model successfully reproduces all of the measured 238 U and 232 Th disequilibria and suggests that the shallow magma reservoir at Erebus is growing. The implication of this modeling is that when the time scale of crystallization is comparable with the half-life of the daughter nuclide of interest (e.g 226 ... Article in Journal/Newspaper Antarc* Antarctica University of Bristol: Bristol Research Journal of Petrology 54 2 235 271 |
institution |
Open Polar |
collection |
University of Bristol: Bristol Research |
op_collection_id |
ftubristolcris |
language |
English |
topic |
Antarctica Erebus volcano HIMU Magma chamber residence time Magma degassing Open-system crystallization U-series isotopes |
spellingShingle |
Antarctica Erebus volcano HIMU Magma chamber residence time Magma degassing Open-system crystallization U-series isotopes Sims, Kenneth W W Pichat, Sylvain Reagan, Mark K. Kyle, Philip R. Dulaiova, Henrietta Dunbar, Nelia W. Prytulak, Julie Sawyer, Georgina Layne, Graham D. Blichert-Toft, Janne Gauthier, Pierre J. Charette, Matthew A. Elliott, Timothy R. Elliott, Tim On the time scales of magma genesis, melt evolution, crystal growth rates and magma degassing in the erebus volcano magmatic system using the 238 U, 235 U and 232 Th decay series |
topic_facet |
Antarctica Erebus volcano HIMU Magma chamber residence time Magma degassing Open-system crystallization U-series isotopes |
description |
We investigate the time scales of magma genesis, melt evolution, crystal growth rates and magma degassing in the Erebus volcano magmatic system using measurements of 238 U- 230 Th- 226 Ra- 210 Pb- 210 Po, 232 Th- 228 Ra- 228 Th and 235 U- 231 Pa- 227 Ac. These are the first measurements of 231 Pa- 227 Ac in volcanic samples and represent the first set of data in a volcanic system to examine the entire suite of relevant 238 U, 235 U and 232 Th decay series nuclides. Our sample suite consists of 22 phonolite volcanic bombs, erupted between 1972 and 2005, and five anorthoclase megacrysts separated from bombs erupted in 1984, 1989, 1993, 2004 and 2005. The 238 U- 230 Th, 230 Th- 226 Ra and 235 U- 231 Pa systems are uniform over the 34 years examined. The anorthoclase megacrysts and phonolite glasses show complementary 226 Ra/ 230 Th disequilibria with ( 226 Ra/ 230 Th) ~40 in the anorthoclase and ~0·75 in the phonolite glass. In all samples, ( 210 Pb/ 226 Ra) is in radioactive equilibrium for both phases. In two phonolite glass samples ( 227 Ac/ 231 Pa) is unity. For the phonolite glasses ( 228 Ra/ 232 Th) is in equilibrium, whereas in the anorthoclase megacrysts it is significantly greater than unity. Instantaneous crystal fractionation, with magma residence times greater than 100 years and less than 10 kyr, can account for the measured 238 U- 230 Th- 226 Ra- 210 Pb and 235 U- 231 Pa- 227 Ac. However, the significant 228 Ra/ 232 Th disequilibria in the anorthoclase megacrysts preclude this simple interpretation. To account for this apparent discrepancy we therefore developed an open-system, continuous crystallization model that incorporates both nuclide ingrowth and decay during crystallization. This open-system model successfully reproduces all of the measured 238 U and 232 Th disequilibria and suggests that the shallow magma reservoir at Erebus is growing. The implication of this modeling is that when the time scale of crystallization is comparable with the half-life of the daughter nuclide of interest (e.g 226 ... |
format |
Article in Journal/Newspaper |
author |
Sims, Kenneth W W Pichat, Sylvain Reagan, Mark K. Kyle, Philip R. Dulaiova, Henrietta Dunbar, Nelia W. Prytulak, Julie Sawyer, Georgina Layne, Graham D. Blichert-Toft, Janne Gauthier, Pierre J. Charette, Matthew A. Elliott, Timothy R. Elliott, Tim |
author_facet |
Sims, Kenneth W W Pichat, Sylvain Reagan, Mark K. Kyle, Philip R. Dulaiova, Henrietta Dunbar, Nelia W. Prytulak, Julie Sawyer, Georgina Layne, Graham D. Blichert-Toft, Janne Gauthier, Pierre J. Charette, Matthew A. Elliott, Timothy R. Elliott, Tim |
author_sort |
Sims, Kenneth W W |
title |
On the time scales of magma genesis, melt evolution, crystal growth rates and magma degassing in the erebus volcano magmatic system using the 238 U, 235 U and 232 Th decay series |
title_short |
On the time scales of magma genesis, melt evolution, crystal growth rates and magma degassing in the erebus volcano magmatic system using the 238 U, 235 U and 232 Th decay series |
title_full |
On the time scales of magma genesis, melt evolution, crystal growth rates and magma degassing in the erebus volcano magmatic system using the 238 U, 235 U and 232 Th decay series |
title_fullStr |
On the time scales of magma genesis, melt evolution, crystal growth rates and magma degassing in the erebus volcano magmatic system using the 238 U, 235 U and 232 Th decay series |
title_full_unstemmed |
On the time scales of magma genesis, melt evolution, crystal growth rates and magma degassing in the erebus volcano magmatic system using the 238 U, 235 U and 232 Th decay series |
title_sort |
on the time scales of magma genesis, melt evolution, crystal growth rates and magma degassing in the erebus volcano magmatic system using the 238 u, 235 u and 232 th decay series |
publishDate |
2013 |
url |
https://hdl.handle.net/1983/1d071f5c-baf0-4f6d-8f02-0e835c46c403 https://research-information.bris.ac.uk/en/publications/1d071f5c-baf0-4f6d-8f02-0e835c46c403 https://doi.org/10.1093/petrology/egs068 http://www.scopus.com/inward/record.url?scp=84872778367&partnerID=8YFLogxK |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_source |
Sims , K W W , Pichat , S , Reagan , M K , Kyle , P R , Dulaiova , H , Dunbar , N W , Prytulak , J , Sawyer , G , Layne , G D , Blichert-Toft , J , Gauthier , P J , Charette , M A , Elliott , T R & Elliott , T 2013 , ' On the time scales of magma genesis, melt evolution, crystal growth rates and magma degassing in the erebus volcano magmatic system using the 238 U, 235 U and 232 Th decay series ' , Journal of Petrology , vol. 54 , no. 2 , pp. 235-271 . https://doi.org/10.1093/petrology/egs068 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1093/petrology/egs068 |
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Journal of Petrology |
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54 |
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2 |
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235 |
op_container_end_page |
271 |
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1789340426216407040 |