A Combined Re-Os and Pt-Os Isotope and HSE Abundance Study of Ru-Os-Ir Alloys from the Kunar and Unga Placer Deposits, the Taimyr Peninsula, Polar Siberia
In order to provide further insights into the origin of Ru-Os-Ir alloys, this study presents new highly siderophile element (HSE: Re, Os, Ir, Ru, Pt, and Pd) abundance and 187Re-187Os and 190Pt-186Os isotope data for detrital grains of native Ru-Os-Ir alloys in placer deposits of the Kunar and Unga...
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ftmdpi:oai:mdpi.com:/2075-163X/12/11/1463/ 2023-08-20T04:10:07+02:00 A Combined Re-Os and Pt-Os Isotope and HSE Abundance Study of Ru-Os-Ir Alloys from the Kunar and Unga Placer Deposits, the Taimyr Peninsula, Polar Siberia Kreshimir N. Malitch Igor S. Puchtel Elena A. Belousova Inna Yu. Badanina agris 2022-11-19 application/pdf https://doi.org/10.3390/min12111463 EN eng Multidisciplinary Digital Publishing Institute Mineral Geochemistry and Geochronology https://dx.doi.org/10.3390/min12111463 https://creativecommons.org/licenses/by/4.0/ Minerals; Volume 12; Issue 11; Pages: 1463 Ru-Os-Ir alloys highly siderophile elements Re-Os and Pt-Os isotopic systems ophiolite mantle the Kunar and Unga placer deposits the Taimyr Peninsula Polar Siberia Text 2022 ftmdpi https://doi.org/10.3390/min12111463 2023-08-01T07:25:00Z In order to provide further insights into the origin of Ru-Os-Ir alloys, this study presents new highly siderophile element (HSE: Re, Os, Ir, Ru, Pt, and Pd) abundance and 187Re-187Os and 190Pt-186Os isotope data for detrital grains of native Ru-Os-Ir alloys in placer deposits of the Kunar and Unga Rivers, which display a close spatial association with the Kunar dunite–harzburgite complex in the northern part of the Taimyr Peninsula in the Polar Siberia. The study utilized electron microprobe analysis, negative thermal ionization mass-spectrometry (N-TIMS) and laser ablation multiple-collector inductively coupled plasma mass-spectrometry (LA MC-ICP-MS). The primary nature of the Ru-Os-Ir alloys is supported by the occurrence of euhedral inclusions of high-Mg olivine (Fo92–93) that fall within the compositional range of mantle olivine. The LA MC-ICP-MS data show similar average initial 187Os/188Os and γ187Os(740 Ma) values for PGM assemblages from the Kunar and Unga deposits of 0.1218 ± 0.0010, −0.18 ± 0.85, and 0.1222 ± 0.0025, +0.10 ± 2.1, respectively. These values are identical, within their respective uncertainties, to the initial 187Os/188Os value of the Ru-Os-Ir alloy grain measured by N-TIMS (0.1218463 ± 0.0000015, γ187Os(740 Ma) = −0.1500 ± 0.0012). The combined 187Re-187Os isotopic data for all studied grains (γ187Os(740 Ma) = −0.02 ± 1.6) indicate evolution of the Kunar and Unga mantle sources with a long-term chondritic 187Re/188Os ratio of 0.401 ± 0.030. In contrast to the 187Os/188Os data, the initial 186Os/188Os value of 0.1198409 ± 0.0000012 (µ186Os(740 Ma) = +34 ± 10) obtained for the same Ru-Os-Ir alloy grain by N-TIMS is suprachondritic and implies evolution of the Kunar and Unga mantle source(s) with a long-term suprachondritic 190Pt/188Os ratio of 0.00247 ± 0.00021. This value is ~40% higher than the average chondritic 190Pt/188Os ratio of 0.00180 and indicates long-term enrichment of the Kunar source in Pt over Os. Establishing the source of this enrichment requires further investigation. Text Taimyr Siberia MDPI Open Access Publishing Kunar ENVELOPE(104.296,104.296,77.666,77.666) Minerals 12 11 1463 |
institution |
Open Polar |
collection |
MDPI Open Access Publishing |
op_collection_id |
ftmdpi |
language |
English |
topic |
Ru-Os-Ir alloys highly siderophile elements Re-Os and Pt-Os isotopic systems ophiolite mantle the Kunar and Unga placer deposits the Taimyr Peninsula Polar Siberia |
spellingShingle |
Ru-Os-Ir alloys highly siderophile elements Re-Os and Pt-Os isotopic systems ophiolite mantle the Kunar and Unga placer deposits the Taimyr Peninsula Polar Siberia Kreshimir N. Malitch Igor S. Puchtel Elena A. Belousova Inna Yu. Badanina A Combined Re-Os and Pt-Os Isotope and HSE Abundance Study of Ru-Os-Ir Alloys from the Kunar and Unga Placer Deposits, the Taimyr Peninsula, Polar Siberia |
topic_facet |
Ru-Os-Ir alloys highly siderophile elements Re-Os and Pt-Os isotopic systems ophiolite mantle the Kunar and Unga placer deposits the Taimyr Peninsula Polar Siberia |
description |
In order to provide further insights into the origin of Ru-Os-Ir alloys, this study presents new highly siderophile element (HSE: Re, Os, Ir, Ru, Pt, and Pd) abundance and 187Re-187Os and 190Pt-186Os isotope data for detrital grains of native Ru-Os-Ir alloys in placer deposits of the Kunar and Unga Rivers, which display a close spatial association with the Kunar dunite–harzburgite complex in the northern part of the Taimyr Peninsula in the Polar Siberia. The study utilized electron microprobe analysis, negative thermal ionization mass-spectrometry (N-TIMS) and laser ablation multiple-collector inductively coupled plasma mass-spectrometry (LA MC-ICP-MS). The primary nature of the Ru-Os-Ir alloys is supported by the occurrence of euhedral inclusions of high-Mg olivine (Fo92–93) that fall within the compositional range of mantle olivine. The LA MC-ICP-MS data show similar average initial 187Os/188Os and γ187Os(740 Ma) values for PGM assemblages from the Kunar and Unga deposits of 0.1218 ± 0.0010, −0.18 ± 0.85, and 0.1222 ± 0.0025, +0.10 ± 2.1, respectively. These values are identical, within their respective uncertainties, to the initial 187Os/188Os value of the Ru-Os-Ir alloy grain measured by N-TIMS (0.1218463 ± 0.0000015, γ187Os(740 Ma) = −0.1500 ± 0.0012). The combined 187Re-187Os isotopic data for all studied grains (γ187Os(740 Ma) = −0.02 ± 1.6) indicate evolution of the Kunar and Unga mantle sources with a long-term chondritic 187Re/188Os ratio of 0.401 ± 0.030. In contrast to the 187Os/188Os data, the initial 186Os/188Os value of 0.1198409 ± 0.0000012 (µ186Os(740 Ma) = +34 ± 10) obtained for the same Ru-Os-Ir alloy grain by N-TIMS is suprachondritic and implies evolution of the Kunar and Unga mantle source(s) with a long-term suprachondritic 190Pt/188Os ratio of 0.00247 ± 0.00021. This value is ~40% higher than the average chondritic 190Pt/188Os ratio of 0.00180 and indicates long-term enrichment of the Kunar source in Pt over Os. Establishing the source of this enrichment requires further investigation. |
format |
Text |
author |
Kreshimir N. Malitch Igor S. Puchtel Elena A. Belousova Inna Yu. Badanina |
author_facet |
Kreshimir N. Malitch Igor S. Puchtel Elena A. Belousova Inna Yu. Badanina |
author_sort |
Kreshimir N. Malitch |
title |
A Combined Re-Os and Pt-Os Isotope and HSE Abundance Study of Ru-Os-Ir Alloys from the Kunar and Unga Placer Deposits, the Taimyr Peninsula, Polar Siberia |
title_short |
A Combined Re-Os and Pt-Os Isotope and HSE Abundance Study of Ru-Os-Ir Alloys from the Kunar and Unga Placer Deposits, the Taimyr Peninsula, Polar Siberia |
title_full |
A Combined Re-Os and Pt-Os Isotope and HSE Abundance Study of Ru-Os-Ir Alloys from the Kunar and Unga Placer Deposits, the Taimyr Peninsula, Polar Siberia |
title_fullStr |
A Combined Re-Os and Pt-Os Isotope and HSE Abundance Study of Ru-Os-Ir Alloys from the Kunar and Unga Placer Deposits, the Taimyr Peninsula, Polar Siberia |
title_full_unstemmed |
A Combined Re-Os and Pt-Os Isotope and HSE Abundance Study of Ru-Os-Ir Alloys from the Kunar and Unga Placer Deposits, the Taimyr Peninsula, Polar Siberia |
title_sort |
combined re-os and pt-os isotope and hse abundance study of ru-os-ir alloys from the kunar and unga placer deposits, the taimyr peninsula, polar siberia |
publisher |
Multidisciplinary Digital Publishing Institute |
publishDate |
2022 |
url |
https://doi.org/10.3390/min12111463 |
op_coverage |
agris |
long_lat |
ENVELOPE(104.296,104.296,77.666,77.666) |
geographic |
Kunar |
geographic_facet |
Kunar |
genre |
Taimyr Siberia |
genre_facet |
Taimyr Siberia |
op_source |
Minerals; Volume 12; Issue 11; Pages: 1463 |
op_relation |
Mineral Geochemistry and Geochronology https://dx.doi.org/10.3390/min12111463 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3390/min12111463 |
container_title |
Minerals |
container_volume |
12 |
container_issue |
11 |
container_start_page |
1463 |
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1774724068961943552 |