Cr-spinel records metasomatism not petrogenesis of mantle rocks

Mantle melts provide a window on processes related to global plate tectonics. The composition of chromian spinel (Cr-spinel) from mafic-ultramafic rocks has been widely used for tracing the geotectonic environments, the degree of mantle melting and the rate of mid-ocean ridge spreading. The assumpti...

Full description

Bibliographic Details
Main Authors: Gamal El Dien, H., Arai, S., Doucet, L.S., Li, Zheng-Xiang, Kil, Y., Fougerouse, Denis, Reddy, Steven, Saxey, David, Hamdy, M.
Format: Journal Article
Language:English
Published: NATURE PUBLISHING GROUP 2019
Subjects:
Online Access:http://purl.org/au-research/grants/arc/FL150100133
http://hdl.handle.net/20.500.11937/79360
_version_ 1848764037437849600
author Gamal El Dien, H.
Arai, S.
Doucet, L.S.
Li, Zheng-Xiang
Kil, Y.
Fougerouse, Denis
Reddy, Steven
Saxey, David
Hamdy, M.
author_facet Gamal El Dien, H.
Arai, S.
Doucet, L.S.
Li, Zheng-Xiang
Kil, Y.
Fougerouse, Denis
Reddy, Steven
Saxey, David
Hamdy, M.
author_sort Gamal El Dien, H.
building Curtin Institutional Repository
collection Online Access
description Mantle melts provide a window on processes related to global plate tectonics. The composition of chromian spinel (Cr-spinel) from mafic-ultramafic rocks has been widely used for tracing the geotectonic environments, the degree of mantle melting and the rate of mid-ocean ridge spreading. The assumption is that Cr-spinel’s core composition (Cr# = Cr/(Cr + Al)) is homogenous, insensitive to post-formation modification and therefore a robust petrogenetic indicator. However, we demonstrate that the composition of Cr-spinel can be modified by fluid/melt-rock interactions in both sub-arc and sub-mid oceanic mantle. Metasomatism can produce Al-Cr heterogeneity in Cr-spinel that lowers the Cr/Al ratio, and therefore modifies the Cr#, making Cr# ineffective as a geotectonic and mantle melting indicator. Our analysis also demonstrates that Cr-spinel is a potential sink for fluid-mobile elements, especially in subduction zone environments. The heterogeneity of Cr# in Cr-spinel can, therefore, be used as an excellent tracer for metasomatic processes.
first_indexed 2025-11-14T11:12:59Z
format Journal Article
id curtin-20.500.11937-79360
institution Curtin University Malaysia
institution_category Local University
language English
last_indexed 2025-11-14T11:12:59Z
publishDate 2019
publisher NATURE PUBLISHING GROUP
recordtype eprints
repository_type Digital Repository
spelling curtin-20.500.11937-793602022-11-23T05:55:14Z Cr-spinel records metasomatism not petrogenesis of mantle rocks Gamal El Dien, H. Arai, S. Doucet, L.S. Li, Zheng-Xiang Kil, Y. Fougerouse, Denis Reddy, Steven Saxey, David Hamdy, M. Science & Technology Multidisciplinary Sciences Science & Technology - Other Topics MID-ATLANTIC RIDGE ANDESITIC AVACHA VOLCANO MARIANA FORE-ARC PERIDOTITE XENOLITHS SERPENTINIZED PERIDOTITES ABYSSAL PERIDOTITES SPREADING RIDGE EASTERN DESERT WEDGE BENEATH KAMCHATKA ARC Mantle melts provide a window on processes related to global plate tectonics. The composition of chromian spinel (Cr-spinel) from mafic-ultramafic rocks has been widely used for tracing the geotectonic environments, the degree of mantle melting and the rate of mid-ocean ridge spreading. The assumption is that Cr-spinel’s core composition (Cr# = Cr/(Cr + Al)) is homogenous, insensitive to post-formation modification and therefore a robust petrogenetic indicator. However, we demonstrate that the composition of Cr-spinel can be modified by fluid/melt-rock interactions in both sub-arc and sub-mid oceanic mantle. Metasomatism can produce Al-Cr heterogeneity in Cr-spinel that lowers the Cr/Al ratio, and therefore modifies the Cr#, making Cr# ineffective as a geotectonic and mantle melting indicator. Our analysis also demonstrates that Cr-spinel is a potential sink for fluid-mobile elements, especially in subduction zone environments. The heterogeneity of Cr# in Cr-spinel can, therefore, be used as an excellent tracer for metasomatic processes. 2019 Journal Article http://hdl.handle.net/20.500.11937/79360 10.1038/s41467-019-13117-1 English http://purl.org/au-research/grants/arc/FL150100133 http://creativecommons.org/licenses/by/4.0/ NATURE PUBLISHING GROUP fulltext
spellingShingle Science & Technology
Multidisciplinary Sciences
Science & Technology - Other Topics
MID-ATLANTIC RIDGE
ANDESITIC AVACHA VOLCANO
MARIANA FORE-ARC
PERIDOTITE XENOLITHS
SERPENTINIZED PERIDOTITES
ABYSSAL PERIDOTITES
SPREADING RIDGE
EASTERN DESERT
WEDGE BENEATH
KAMCHATKA ARC
Gamal El Dien, H.
Arai, S.
Doucet, L.S.
Li, Zheng-Xiang
Kil, Y.
Fougerouse, Denis
Reddy, Steven
Saxey, David
Hamdy, M.
Cr-spinel records metasomatism not petrogenesis of mantle rocks
title Cr-spinel records metasomatism not petrogenesis of mantle rocks
title_full Cr-spinel records metasomatism not petrogenesis of mantle rocks
title_fullStr Cr-spinel records metasomatism not petrogenesis of mantle rocks
title_full_unstemmed Cr-spinel records metasomatism not petrogenesis of mantle rocks
title_short Cr-spinel records metasomatism not petrogenesis of mantle rocks
title_sort cr-spinel records metasomatism not petrogenesis of mantle rocks
topic Science & Technology
Multidisciplinary Sciences
Science & Technology - Other Topics
MID-ATLANTIC RIDGE
ANDESITIC AVACHA VOLCANO
MARIANA FORE-ARC
PERIDOTITE XENOLITHS
SERPENTINIZED PERIDOTITES
ABYSSAL PERIDOTITES
SPREADING RIDGE
EASTERN DESERT
WEDGE BENEATH
KAMCHATKA ARC
url http://purl.org/au-research/grants/arc/FL150100133
http://hdl.handle.net/20.500.11937/79360