Silicon and oxygen isotopes unravel quartz formation processes in the Icelandic crust
Quartz formation processes in the Icelandic crust were assessed using coupled δ18O and δ30Si systematics of silica deposits formed over a wide temperature range (<150 to >550 °C). Magmatic quartz reveals δ18O (-5.6 to +6.6 ‰) and δ30Si (-0.4 ± 0.2 ‰) values representative of mantle- and crusta...
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ftnrm:oai:DiVA.org:nrm-3190 2023-05-15T16:50:15+02:00 Silicon and oxygen isotopes unravel quartz formation processes in the Icelandic crust Kleine, B. I. Stefánsson, A. Halldórsson, S. A. Whitehouse, Martin J. Jónasson, K. 2018 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:nrm:diva-3190 eng eng Enheten för geovetenskap , 2018, 7, s. 5-11 Geochemical Perspectives Letters, 2018, 7, s. 5-11 http://urn.kb.se/resolve?urn=urn:nbn:se:nrm:diva-3190 info:eu-repo/semantics/openAccess Earth and Related Environmental Sciences Geovetenskap och miljövetenskap Article in journal info:eu-repo/semantics/article text 2018 ftnrm 2021-10-08T07:21:19Z Quartz formation processes in the Icelandic crust were assessed using coupled δ18O and δ30Si systematics of silica deposits formed over a wide temperature range (<150 to >550 °C). Magmatic quartz reveals δ18O (-5.6 to +6.6 ‰) and δ30Si (-0.4 ± 0.2 ‰) values representative of mantle- and crustally-derived melts in Iceland. Hydrothermal quartz and silica polymorphs display a larger range of δ18O (-9.3 to +30.1 ‰) and δ30Si (-4.6 to +0.7 ‰) values. Isotope modelling reveals that such large variations are consistent with variable water sources and equilibrium isotope fractionation between fluids and quartz associated with secondary processes occurring in the crust, including fluid-rock interaction, boiling and cooling. In context of published δ18O and δ30Si data on hydrothermal silica deposits, we demonstrate that large ranges in δ30Si values coupled to insignificant δ18O variations may result from silica precipitation in a hydrothermal fluid conduit associated with near-surface cooling. While equilibrium isotope fractionation between fluids and quartz seems to prevail at high temperatures, kinetic fractionation likely influences isotope systematics at low temperatures. Article in Journal/Newspaper Iceland Swedish Museum of Natural History: Publications (DiVA) |
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Open Polar |
collection |
Swedish Museum of Natural History: Publications (DiVA) |
op_collection_id |
ftnrm |
language |
English |
topic |
Earth and Related Environmental Sciences Geovetenskap och miljövetenskap |
spellingShingle |
Earth and Related Environmental Sciences Geovetenskap och miljövetenskap Kleine, B. I. Stefánsson, A. Halldórsson, S. A. Whitehouse, Martin J. Jónasson, K. Silicon and oxygen isotopes unravel quartz formation processes in the Icelandic crust |
topic_facet |
Earth and Related Environmental Sciences Geovetenskap och miljövetenskap |
description |
Quartz formation processes in the Icelandic crust were assessed using coupled δ18O and δ30Si systematics of silica deposits formed over a wide temperature range (<150 to >550 °C). Magmatic quartz reveals δ18O (-5.6 to +6.6 ‰) and δ30Si (-0.4 ± 0.2 ‰) values representative of mantle- and crustally-derived melts in Iceland. Hydrothermal quartz and silica polymorphs display a larger range of δ18O (-9.3 to +30.1 ‰) and δ30Si (-4.6 to +0.7 ‰) values. Isotope modelling reveals that such large variations are consistent with variable water sources and equilibrium isotope fractionation between fluids and quartz associated with secondary processes occurring in the crust, including fluid-rock interaction, boiling and cooling. In context of published δ18O and δ30Si data on hydrothermal silica deposits, we demonstrate that large ranges in δ30Si values coupled to insignificant δ18O variations may result from silica precipitation in a hydrothermal fluid conduit associated with near-surface cooling. While equilibrium isotope fractionation between fluids and quartz seems to prevail at high temperatures, kinetic fractionation likely influences isotope systematics at low temperatures. |
format |
Article in Journal/Newspaper |
author |
Kleine, B. I. Stefánsson, A. Halldórsson, S. A. Whitehouse, Martin J. Jónasson, K. |
author_facet |
Kleine, B. I. Stefánsson, A. Halldórsson, S. A. Whitehouse, Martin J. Jónasson, K. |
author_sort |
Kleine, B. I. |
title |
Silicon and oxygen isotopes unravel quartz formation processes in the Icelandic crust |
title_short |
Silicon and oxygen isotopes unravel quartz formation processes in the Icelandic crust |
title_full |
Silicon and oxygen isotopes unravel quartz formation processes in the Icelandic crust |
title_fullStr |
Silicon and oxygen isotopes unravel quartz formation processes in the Icelandic crust |
title_full_unstemmed |
Silicon and oxygen isotopes unravel quartz formation processes in the Icelandic crust |
title_sort |
silicon and oxygen isotopes unravel quartz formation processes in the icelandic crust |
publisher |
Enheten för geovetenskap |
publishDate |
2018 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:nrm:diva-3190 |
genre |
Iceland |
genre_facet |
Iceland |
op_relation |
, 2018, 7, s. 5-11 Geochemical Perspectives Letters, 2018, 7, s. 5-11 http://urn.kb.se/resolve?urn=urn:nbn:se:nrm:diva-3190 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766040425483730944 |