Time-scales for magmatic differentiation at the Snaefellsjökull central volcano, western Iceland: constraints from U-Th-Pa-Ra disequilibria in post-glacial lavas
We present major and trace element and Sr–Nd–Pb and U–Th–Pa–Ra isotope data for a small sample suite of primarily post-glacial, mildly alkalic volcanic rocks from the Snaefellsjökull central volcano situated off the main rift systems in western Iceland. The volcanic rocks are crystal-poor and range...
Published in: | Geochimica et Cosmochimica Acta |
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Format: | Article in Journal/Newspaper |
Language: | English |
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Elsevier
2009
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Online Access: | https://oceanrep.geomar.de/id/eprint/5935/ https://oceanrep.geomar.de/id/eprint/5935/1/532_Hoernle_2009_TimescalesForMagmaticDifferentiationAt_Artzeit_pubid11556.pdf https://doi.org/10.1016/j.gca.2008.11.021 |
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ftoceanrep:oai:oceanrep.geomar.de:5935 2023-05-15T16:48:43+02:00 Time-scales for magmatic differentiation at the Snaefellsjökull central volcano, western Iceland: constraints from U-Th-Pa-Ra disequilibria in post-glacial lavas Kokfelt, Thomas Find Hoernle, Kaj Lundstrom, Craig Hauff, Folkmar van den Bogaard, Christel 2009 text https://oceanrep.geomar.de/id/eprint/5935/ https://oceanrep.geomar.de/id/eprint/5935/1/532_Hoernle_2009_TimescalesForMagmaticDifferentiationAt_Artzeit_pubid11556.pdf https://doi.org/10.1016/j.gca.2008.11.021 en eng Elsevier https://oceanrep.geomar.de/id/eprint/5935/1/532_Hoernle_2009_TimescalesForMagmaticDifferentiationAt_Artzeit_pubid11556.pdf Kokfelt, T. F., Hoernle, K. , Lundstrom, C., Hauff, F. and van den Bogaard, C. (2009) Time-scales for magmatic differentiation at the Snaefellsjökull central volcano, western Iceland: constraints from U-Th-Pa-Ra disequilibria in post-glacial lavas. Geochimica et Cosmochimica Acta, 73 (4). pp. 1120-1144. DOI 10.1016/j.gca.2008.11.021 <https://doi.org/10.1016/j.gca.2008.11.021>. doi:10.1016/j.gca.2008.11.021 info:eu-repo/semantics/restrictedAccess Article PeerReviewed 2009 ftoceanrep https://doi.org/10.1016/j.gca.2008.11.021 2023-04-07T14:51:58Z We present major and trace element and Sr–Nd–Pb and U–Th–Pa–Ra isotope data for a small sample suite of primarily post-glacial, mildly alkalic volcanic rocks from the Snaefellsjökull central volcano situated off the main rift systems in western Iceland. The volcanic rocks are crystal-poor and range from olivine alkali basalt to trachyte and show tight correlations of major and trace elements that are explained by fractional crystallization involving removal of olivine, plagioclase, clinopyroxene, Fe–Ti oxide and apatite. Sr–Nd–Pb isotopes are practically invariant, consistent with derivation from the same source region. During fractionation from primitive basalt to evolved trachyte, (230Th/232Th), (230Th/238U) and (231Pa/235U) decrease progressively at broadly constant (238U/232Th). A continuous closed-system fractionation model that assumes constant initial (230Th/232Th) in the basaltic precursor melt indicates that hawaiite was derived from olivine basalt by not, vert, similar50% fractional crystallization within View the MathML source and trachyte by not, vert, similar80% fractionation within View the MathML source. An overrepresentation of evolved basalts and hawaiites with young inferred magma ages in the dataset is consistent with the parental precursor to these magmas intruded into the sub-volcanic magma plumbing system as a consequence of lithospheric rebound caused by deglaciation. Lavas affected by apatite removal have higher (231Pa/235U) than predicted for simple radioactive decay, suggesting apatite significantly fractionates U from Pa. The proposed fractionation model consistently explains our U-series data assuming View the MathML source and View the MathML source and View the MathML source. If applicable, these D values would indicate that the effect of apatite fractionation must be adequately considered when assessing differentiation time scales using (231Pa/235U) disequilibria data. Article in Journal/Newspaper Iceland OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Geochimica et Cosmochimica Acta 73 4 1120 1144 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
We present major and trace element and Sr–Nd–Pb and U–Th–Pa–Ra isotope data for a small sample suite of primarily post-glacial, mildly alkalic volcanic rocks from the Snaefellsjökull central volcano situated off the main rift systems in western Iceland. The volcanic rocks are crystal-poor and range from olivine alkali basalt to trachyte and show tight correlations of major and trace elements that are explained by fractional crystallization involving removal of olivine, plagioclase, clinopyroxene, Fe–Ti oxide and apatite. Sr–Nd–Pb isotopes are practically invariant, consistent with derivation from the same source region. During fractionation from primitive basalt to evolved trachyte, (230Th/232Th), (230Th/238U) and (231Pa/235U) decrease progressively at broadly constant (238U/232Th). A continuous closed-system fractionation model that assumes constant initial (230Th/232Th) in the basaltic precursor melt indicates that hawaiite was derived from olivine basalt by not, vert, similar50% fractional crystallization within View the MathML source and trachyte by not, vert, similar80% fractionation within View the MathML source. An overrepresentation of evolved basalts and hawaiites with young inferred magma ages in the dataset is consistent with the parental precursor to these magmas intruded into the sub-volcanic magma plumbing system as a consequence of lithospheric rebound caused by deglaciation. Lavas affected by apatite removal have higher (231Pa/235U) than predicted for simple radioactive decay, suggesting apatite significantly fractionates U from Pa. The proposed fractionation model consistently explains our U-series data assuming View the MathML source and View the MathML source and View the MathML source. If applicable, these D values would indicate that the effect of apatite fractionation must be adequately considered when assessing differentiation time scales using (231Pa/235U) disequilibria data. |
format |
Article in Journal/Newspaper |
author |
Kokfelt, Thomas Find Hoernle, Kaj Lundstrom, Craig Hauff, Folkmar van den Bogaard, Christel |
spellingShingle |
Kokfelt, Thomas Find Hoernle, Kaj Lundstrom, Craig Hauff, Folkmar van den Bogaard, Christel Time-scales for magmatic differentiation at the Snaefellsjökull central volcano, western Iceland: constraints from U-Th-Pa-Ra disequilibria in post-glacial lavas |
author_facet |
Kokfelt, Thomas Find Hoernle, Kaj Lundstrom, Craig Hauff, Folkmar van den Bogaard, Christel |
author_sort |
Kokfelt, Thomas Find |
title |
Time-scales for magmatic differentiation at the Snaefellsjökull central volcano, western Iceland: constraints from U-Th-Pa-Ra disequilibria in post-glacial lavas |
title_short |
Time-scales for magmatic differentiation at the Snaefellsjökull central volcano, western Iceland: constraints from U-Th-Pa-Ra disequilibria in post-glacial lavas |
title_full |
Time-scales for magmatic differentiation at the Snaefellsjökull central volcano, western Iceland: constraints from U-Th-Pa-Ra disequilibria in post-glacial lavas |
title_fullStr |
Time-scales for magmatic differentiation at the Snaefellsjökull central volcano, western Iceland: constraints from U-Th-Pa-Ra disequilibria in post-glacial lavas |
title_full_unstemmed |
Time-scales for magmatic differentiation at the Snaefellsjökull central volcano, western Iceland: constraints from U-Th-Pa-Ra disequilibria in post-glacial lavas |
title_sort |
time-scales for magmatic differentiation at the snaefellsjökull central volcano, western iceland: constraints from u-th-pa-ra disequilibria in post-glacial lavas |
publisher |
Elsevier |
publishDate |
2009 |
url |
https://oceanrep.geomar.de/id/eprint/5935/ https://oceanrep.geomar.de/id/eprint/5935/1/532_Hoernle_2009_TimescalesForMagmaticDifferentiationAt_Artzeit_pubid11556.pdf https://doi.org/10.1016/j.gca.2008.11.021 |
genre |
Iceland |
genre_facet |
Iceland |
op_relation |
https://oceanrep.geomar.de/id/eprint/5935/1/532_Hoernle_2009_TimescalesForMagmaticDifferentiationAt_Artzeit_pubid11556.pdf Kokfelt, T. F., Hoernle, K. , Lundstrom, C., Hauff, F. and van den Bogaard, C. (2009) Time-scales for magmatic differentiation at the Snaefellsjökull central volcano, western Iceland: constraints from U-Th-Pa-Ra disequilibria in post-glacial lavas. Geochimica et Cosmochimica Acta, 73 (4). pp. 1120-1144. DOI 10.1016/j.gca.2008.11.021 <https://doi.org/10.1016/j.gca.2008.11.021>. doi:10.1016/j.gca.2008.11.021 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/j.gca.2008.11.021 |
container_title |
Geochimica et Cosmochimica Acta |
container_volume |
73 |
container_issue |
4 |
container_start_page |
1120 |
op_container_end_page |
1144 |
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1766038801797349376 |