The origin of platinum group minerals in oceanic crust
Highly siderophile elements (HSEs), including Re and Os, are used extensively as geochemical tracers and geochronometers to investigate the formation and evolution of Earth's crust and mantle. Mantle rocks are commonly serpentinized, but the effect of serpentinization on the distribution of HSE...
Published in: | Geology |
---|---|
Main Authors: | , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
2023
|
Subjects: | |
Online Access: | https://hdl.handle.net/20.500.11937/94768 https://doi.org/10.1130/G50927.1 |
id |
ftcurtin:oai:espace.curtin.edu.au:20.500.11937/94768 |
---|---|
record_format |
openpolar |
spelling |
ftcurtin:oai:espace.curtin.edu.au:20.500.11937/94768 2024-05-19T07:43:48+00:00 The origin of platinum group minerals in oceanic crust Evans, Katy Reddy, Steven Merle, R. Fougerouse, Denis Rickard, William Saxey, David Park, J.W. Doucet, Luc Jourdan, Fred 2023 fulltext https://hdl.handle.net/20.500.11937/94768 https://doi.org/10.1130/G50927.1 unknown http://purl.org/au-research/grants/arc/DP210101866 http://purl.org/au-research/grants/arc/DP210102625 http://hdl.handle.net/20.500.11937/94768 doi:10.1130/G50927.1 http://creativecommons.org/licenses/by/4.0/ Journal Article 2023 ftcurtin https://doi.org/20.500.11937/9476810.1130/G50927.1 2024-04-23T23:31:51Z Highly siderophile elements (HSEs), including Re and Os, are used extensively as geochemical tracers and geochronometers to investigate the formation and evolution of Earth's crust and mantle. Mantle rocks are commonly serpentinized, but the effect of serpentinization on the distribution of HSEs is controversial because HSEs are commonly hosted by rare, micrometerto sub-micrometer-scale grains of platinum group minerals (PGMs) of ambiguous origin that are challenging to identify, characterize, and interpret. In this study, atom probe tomography (APT) is used to characterize two spatially close PGM grains hosted by a partially serpentinized harzburgite from Macquarie Island, Australia. The APT data reveal an extraordinary level of detail that provides insights into the origin of a complex Cu-Pt alloy grain (average composition ~Cu4Pt). The grain hosts Fe-, Ni-, and Pt-rich sub-grains associated with Rh, variably overlapping networks of Pd- and Cd-enrichment, and OH-rich volumes identified as fluid inclusions. Osmium and Ru are hosted by an idioblastic laurite (RuS2) grain. Compositional, textural, and phase-diagram constraints are consistent with a modified pre-serpentinization origin for the PGMs, and a comparison between observed and calculated grain distributions indicate that while Os isotope ratios were probably unaffected by serpentinization, whole-rock and grain-scale HSE and isotopic ratios may have been decoupled during serpentinization. Article in Journal/Newspaper Macquarie Island Curtin University: espace Geology 51 6 554 558 |
institution |
Open Polar |
collection |
Curtin University: espace |
op_collection_id |
ftcurtin |
language |
unknown |
description |
Highly siderophile elements (HSEs), including Re and Os, are used extensively as geochemical tracers and geochronometers to investigate the formation and evolution of Earth's crust and mantle. Mantle rocks are commonly serpentinized, but the effect of serpentinization on the distribution of HSEs is controversial because HSEs are commonly hosted by rare, micrometerto sub-micrometer-scale grains of platinum group minerals (PGMs) of ambiguous origin that are challenging to identify, characterize, and interpret. In this study, atom probe tomography (APT) is used to characterize two spatially close PGM grains hosted by a partially serpentinized harzburgite from Macquarie Island, Australia. The APT data reveal an extraordinary level of detail that provides insights into the origin of a complex Cu-Pt alloy grain (average composition ~Cu4Pt). The grain hosts Fe-, Ni-, and Pt-rich sub-grains associated with Rh, variably overlapping networks of Pd- and Cd-enrichment, and OH-rich volumes identified as fluid inclusions. Osmium and Ru are hosted by an idioblastic laurite (RuS2) grain. Compositional, textural, and phase-diagram constraints are consistent with a modified pre-serpentinization origin for the PGMs, and a comparison between observed and calculated grain distributions indicate that while Os isotope ratios were probably unaffected by serpentinization, whole-rock and grain-scale HSE and isotopic ratios may have been decoupled during serpentinization. |
format |
Article in Journal/Newspaper |
author |
Evans, Katy Reddy, Steven Merle, R. Fougerouse, Denis Rickard, William Saxey, David Park, J.W. Doucet, Luc Jourdan, Fred |
spellingShingle |
Evans, Katy Reddy, Steven Merle, R. Fougerouse, Denis Rickard, William Saxey, David Park, J.W. Doucet, Luc Jourdan, Fred The origin of platinum group minerals in oceanic crust |
author_facet |
Evans, Katy Reddy, Steven Merle, R. Fougerouse, Denis Rickard, William Saxey, David Park, J.W. Doucet, Luc Jourdan, Fred |
author_sort |
Evans, Katy |
title |
The origin of platinum group minerals in oceanic crust |
title_short |
The origin of platinum group minerals in oceanic crust |
title_full |
The origin of platinum group minerals in oceanic crust |
title_fullStr |
The origin of platinum group minerals in oceanic crust |
title_full_unstemmed |
The origin of platinum group minerals in oceanic crust |
title_sort |
origin of platinum group minerals in oceanic crust |
publishDate |
2023 |
url |
https://hdl.handle.net/20.500.11937/94768 https://doi.org/10.1130/G50927.1 |
genre |
Macquarie Island |
genre_facet |
Macquarie Island |
op_relation |
http://purl.org/au-research/grants/arc/DP210101866 http://purl.org/au-research/grants/arc/DP210102625 http://hdl.handle.net/20.500.11937/94768 doi:10.1130/G50927.1 |
op_rights |
http://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/20.500.11937/9476810.1130/G50927.1 |
container_title |
Geology |
container_volume |
51 |
container_issue |
6 |
container_start_page |
554 |
op_container_end_page |
558 |
_version_ |
1799483550624382976 |