Competing effects of spreading rate, crystal fractionation and source variability on Fe isotope systematics in mid-ocean ridge lavas
Abstract Two-thirds of the Earth is covered by mid-ocean ridge basalts, which form along a network of divergent plate margins. Basalts along these margins display a chemical diversity, which is consequent to a complex interplay of partial mantle melting in the upper mantle and magmatic differentiati...
Published in: | Scientific Reports |
---|---|
Main Authors: | , , , , |
Other Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Springer Science and Business Media LLC
2021
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1038/s41598-021-83387-7 http://www.nature.com/articles/s41598-021-83387-7.pdf http://www.nature.com/articles/s41598-021-83387-7 |
id |
crspringernat:10.1038/s41598-021-83387-7 |
---|---|
record_format |
openpolar |
spelling |
crspringernat:10.1038/s41598-021-83387-7 2023-05-15T15:10:18+02:00 Competing effects of spreading rate, crystal fractionation and source variability on Fe isotope systematics in mid-ocean ridge lavas Richter, Marianne Nebel, Oliver Schwindinger, Martin Nebel-Jacobsen, Yona Dick, Henry J. B. Australian Research Council National Science Foundation 2021 http://dx.doi.org/10.1038/s41598-021-83387-7 http://www.nature.com/articles/s41598-021-83387-7.pdf http://www.nature.com/articles/s41598-021-83387-7 en eng Springer Science and Business Media LLC https://creativecommons.org/licenses/by/4.0 https://creativecommons.org/licenses/by/4.0 CC-BY Scientific Reports volume 11, issue 1 ISSN 2045-2322 Multidisciplinary journal-article 2021 crspringernat https://doi.org/10.1038/s41598-021-83387-7 2022-01-04T11:59:06Z Abstract Two-thirds of the Earth is covered by mid-ocean ridge basalts, which form along a network of divergent plate margins. Basalts along these margins display a chemical diversity, which is consequent to a complex interplay of partial mantle melting in the upper mantle and magmatic differentiation processes in lower crustal levels. Igneous differentiation (crystal fractionation, partial melting) and source heterogeneity, in general, are key drivers creating variable chemistry in mid-ocean ridge basalts. This variability is reflected in iron isotope systematics (expressed as δ 57 Fe), showing a total range of 0.2 ‰ from δ 57 Fe = + 0.05 to + 0.25 ‰. Respective contributions of source heterogeneity and magma differentiation leading to this diversity, however, remain elusive. This study investigates the iron isotope systematics in basalts from the ultraslow spreading Gakkel Ridge in the Arctic Ocean and compares them to existing data from the fast spreading East Pacific Rise ridge. Results indicate that Gakkel lavas are driven to heavier iron isotope compositions through partial melting processes, whereas effects of igneous differentiation are minor. This is in stark contrast to fast spreading ridges showing reversed effects of near negligible partial melting effects followed by large isotope fractionation along the liquid line of descent. Gakkel lavas further reveal mantle heterogeneity that is superimposed on the igneous differentiation effects, showing that upper mantle Fe isotope heterogeneity can be transmitted into erupting basalts in the absence of homogenisation processes in sub-oceanic magma chambers. Article in Journal/Newspaper Arctic Arctic Ocean Springer Nature (via Crossref) Arctic Arctic Ocean Gakkel Ridge ENVELOPE(90.000,90.000,87.000,87.000) Pacific Scientific Reports 11 1 |
institution |
Open Polar |
collection |
Springer Nature (via Crossref) |
op_collection_id |
crspringernat |
language |
English |
topic |
Multidisciplinary |
spellingShingle |
Multidisciplinary Richter, Marianne Nebel, Oliver Schwindinger, Martin Nebel-Jacobsen, Yona Dick, Henry J. B. Competing effects of spreading rate, crystal fractionation and source variability on Fe isotope systematics in mid-ocean ridge lavas |
topic_facet |
Multidisciplinary |
description |
Abstract Two-thirds of the Earth is covered by mid-ocean ridge basalts, which form along a network of divergent plate margins. Basalts along these margins display a chemical diversity, which is consequent to a complex interplay of partial mantle melting in the upper mantle and magmatic differentiation processes in lower crustal levels. Igneous differentiation (crystal fractionation, partial melting) and source heterogeneity, in general, are key drivers creating variable chemistry in mid-ocean ridge basalts. This variability is reflected in iron isotope systematics (expressed as δ 57 Fe), showing a total range of 0.2 ‰ from δ 57 Fe = + 0.05 to + 0.25 ‰. Respective contributions of source heterogeneity and magma differentiation leading to this diversity, however, remain elusive. This study investigates the iron isotope systematics in basalts from the ultraslow spreading Gakkel Ridge in the Arctic Ocean and compares them to existing data from the fast spreading East Pacific Rise ridge. Results indicate that Gakkel lavas are driven to heavier iron isotope compositions through partial melting processes, whereas effects of igneous differentiation are minor. This is in stark contrast to fast spreading ridges showing reversed effects of near negligible partial melting effects followed by large isotope fractionation along the liquid line of descent. Gakkel lavas further reveal mantle heterogeneity that is superimposed on the igneous differentiation effects, showing that upper mantle Fe isotope heterogeneity can be transmitted into erupting basalts in the absence of homogenisation processes in sub-oceanic magma chambers. |
author2 |
Australian Research Council National Science Foundation |
format |
Article in Journal/Newspaper |
author |
Richter, Marianne Nebel, Oliver Schwindinger, Martin Nebel-Jacobsen, Yona Dick, Henry J. B. |
author_facet |
Richter, Marianne Nebel, Oliver Schwindinger, Martin Nebel-Jacobsen, Yona Dick, Henry J. B. |
author_sort |
Richter, Marianne |
title |
Competing effects of spreading rate, crystal fractionation and source variability on Fe isotope systematics in mid-ocean ridge lavas |
title_short |
Competing effects of spreading rate, crystal fractionation and source variability on Fe isotope systematics in mid-ocean ridge lavas |
title_full |
Competing effects of spreading rate, crystal fractionation and source variability on Fe isotope systematics in mid-ocean ridge lavas |
title_fullStr |
Competing effects of spreading rate, crystal fractionation and source variability on Fe isotope systematics in mid-ocean ridge lavas |
title_full_unstemmed |
Competing effects of spreading rate, crystal fractionation and source variability on Fe isotope systematics in mid-ocean ridge lavas |
title_sort |
competing effects of spreading rate, crystal fractionation and source variability on fe isotope systematics in mid-ocean ridge lavas |
publisher |
Springer Science and Business Media LLC |
publishDate |
2021 |
url |
http://dx.doi.org/10.1038/s41598-021-83387-7 http://www.nature.com/articles/s41598-021-83387-7.pdf http://www.nature.com/articles/s41598-021-83387-7 |
long_lat |
ENVELOPE(90.000,90.000,87.000,87.000) |
geographic |
Arctic Arctic Ocean Gakkel Ridge Pacific |
geographic_facet |
Arctic Arctic Ocean Gakkel Ridge Pacific |
genre |
Arctic Arctic Ocean |
genre_facet |
Arctic Arctic Ocean |
op_source |
Scientific Reports volume 11, issue 1 ISSN 2045-2322 |
op_rights |
https://creativecommons.org/licenses/by/4.0 https://creativecommons.org/licenses/by/4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1038/s41598-021-83387-7 |
container_title |
Scientific Reports |
container_volume |
11 |
container_issue |
1 |
_version_ |
1766341338709622784 |