In-Situ Crystallization and Continuous Modification of Chromian Spinel in the “Sulfide-Poor Platinum-Group Metal Ores” of the Norilsk-1 Intrusion (Northern Siberia, Russia)
Layers rich in chromian spinel (Cr-spinel) occur in numerous differentiated and layered intrusions. These layers are often characterized by elevated and even economic concentrations of platinum-group-elements (PGEs), but only scarce sulfide mineralization. One particular type of such lithology occur...
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ftmdpi:oai:mdpi.com:/2075-163X/10/6/498/ 2023-08-20T04:08:07+02:00 In-Situ Crystallization and Continuous Modification of Chromian Spinel in the “Sulfide-Poor Platinum-Group Metal Ores” of the Norilsk-1 Intrusion (Northern Siberia, Russia) Ivan F. Chayka Liudmila M. Zhitova Tatiana N. Antsiferova Adam Abersteiner Artem Ya. Shevko Andrey E. Izokh Nadezhda D. Tolstykh Marina P. Gora Valery M. Chubarov Vadim S. Kamenetsky agris 2020-05-30 application/pdf https://doi.org/10.3390/min10060498 EN eng Multidisciplinary Digital Publishing Institute Crystallography and Physical Chemistry of Minerals & Nanominerals https://dx.doi.org/10.3390/min10060498 https://creativecommons.org/licenses/by/4.0/ Minerals; Volume 10; Issue 6; Pages: 498 Cr-spinel chromite layered intrusion Norilsk-1 Text 2020 ftmdpi https://doi.org/10.3390/min10060498 2023-07-31T23:34:14Z Layers rich in chromian spinel (Cr-spinel) occur in numerous differentiated and layered intrusions. These layers are often characterized by elevated and even economic concentrations of platinum-group-elements (PGEs), but only scarce sulfide mineralization. One particular type of such lithology occurs in the roof parts of the Norilsk-type differentiated intrusions (Russia) and is referred to as the “sulfide-poor PGE ores”. We investigated rocks containing variable enrichments in Cr-spinel, sulfides, and platinum-group minerals (PGMs) from two sections of the upper zone of the Norilsk-1 intrusion, with a focus on Cr-spinel. The rocks are dominated by two lithological types: (1) leucogabbro/troctolitic and (2) olivine-gabbro. Fine-grained (5–100 μm) disperse disseminations with varying modal abundances of Cr-spinel are characteristic for the rocks studied. Those abundances range from scarce mineralization through to very dense (up to 30 vol. % Cr-spinel) cloud-like accumulations. However, compact-grained accumulations and cumulate-like textures, which are typical for chromitites of layered intrusions, are not characteristic for the studied rocks. Instead, the disseminations exhibit chain- and trail-like alignments of Cr-spinel grains, which cross the boundaries between enclosing silicates, and sub-circular arrangements. The study revealed millimeter-scaled patchy distribution of Cr-spinel compositions within a given dissemination with Cr-spinel chemistry being strongly correlated with a kind of the enclosing silicate. (1) In unaltered rocks, plagioclase hosts more magnesian Cr-spinel (Mg# 30–60), while Cr-spinel in mafic minerals is less magnesian (Mg# 18–35). (2) In altered rocks, more magnesian Cr-spinel is hosted by less altered silicates, while strongly altered silicates mainly host less magnesian Cr-spinel. Systematics of trivalent cations exhibits divergent trends, even on a scale of a thin section, and depends on a kind of hosting lithology. Leucogabbro/troctolite lithologies contain Cr-spinel with ... Text norilsk Siberia MDPI Open Access Publishing Norilsk ENVELOPE(88.203,88.203,69.354,69.354) Minerals 10 6 498 |
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Open Polar |
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MDPI Open Access Publishing |
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ftmdpi |
language |
English |
topic |
Cr-spinel chromite layered intrusion Norilsk-1 |
spellingShingle |
Cr-spinel chromite layered intrusion Norilsk-1 Ivan F. Chayka Liudmila M. Zhitova Tatiana N. Antsiferova Adam Abersteiner Artem Ya. Shevko Andrey E. Izokh Nadezhda D. Tolstykh Marina P. Gora Valery M. Chubarov Vadim S. Kamenetsky In-Situ Crystallization and Continuous Modification of Chromian Spinel in the “Sulfide-Poor Platinum-Group Metal Ores” of the Norilsk-1 Intrusion (Northern Siberia, Russia) |
topic_facet |
Cr-spinel chromite layered intrusion Norilsk-1 |
description |
Layers rich in chromian spinel (Cr-spinel) occur in numerous differentiated and layered intrusions. These layers are often characterized by elevated and even economic concentrations of platinum-group-elements (PGEs), but only scarce sulfide mineralization. One particular type of such lithology occurs in the roof parts of the Norilsk-type differentiated intrusions (Russia) and is referred to as the “sulfide-poor PGE ores”. We investigated rocks containing variable enrichments in Cr-spinel, sulfides, and platinum-group minerals (PGMs) from two sections of the upper zone of the Norilsk-1 intrusion, with a focus on Cr-spinel. The rocks are dominated by two lithological types: (1) leucogabbro/troctolitic and (2) olivine-gabbro. Fine-grained (5–100 μm) disperse disseminations with varying modal abundances of Cr-spinel are characteristic for the rocks studied. Those abundances range from scarce mineralization through to very dense (up to 30 vol. % Cr-spinel) cloud-like accumulations. However, compact-grained accumulations and cumulate-like textures, which are typical for chromitites of layered intrusions, are not characteristic for the studied rocks. Instead, the disseminations exhibit chain- and trail-like alignments of Cr-spinel grains, which cross the boundaries between enclosing silicates, and sub-circular arrangements. The study revealed millimeter-scaled patchy distribution of Cr-spinel compositions within a given dissemination with Cr-spinel chemistry being strongly correlated with a kind of the enclosing silicate. (1) In unaltered rocks, plagioclase hosts more magnesian Cr-spinel (Mg# 30–60), while Cr-spinel in mafic minerals is less magnesian (Mg# 18–35). (2) In altered rocks, more magnesian Cr-spinel is hosted by less altered silicates, while strongly altered silicates mainly host less magnesian Cr-spinel. Systematics of trivalent cations exhibits divergent trends, even on a scale of a thin section, and depends on a kind of hosting lithology. Leucogabbro/troctolite lithologies contain Cr-spinel with ... |
format |
Text |
author |
Ivan F. Chayka Liudmila M. Zhitova Tatiana N. Antsiferova Adam Abersteiner Artem Ya. Shevko Andrey E. Izokh Nadezhda D. Tolstykh Marina P. Gora Valery M. Chubarov Vadim S. Kamenetsky |
author_facet |
Ivan F. Chayka Liudmila M. Zhitova Tatiana N. Antsiferova Adam Abersteiner Artem Ya. Shevko Andrey E. Izokh Nadezhda D. Tolstykh Marina P. Gora Valery M. Chubarov Vadim S. Kamenetsky |
author_sort |
Ivan F. Chayka |
title |
In-Situ Crystallization and Continuous Modification of Chromian Spinel in the “Sulfide-Poor Platinum-Group Metal Ores” of the Norilsk-1 Intrusion (Northern Siberia, Russia) |
title_short |
In-Situ Crystallization and Continuous Modification of Chromian Spinel in the “Sulfide-Poor Platinum-Group Metal Ores” of the Norilsk-1 Intrusion (Northern Siberia, Russia) |
title_full |
In-Situ Crystallization and Continuous Modification of Chromian Spinel in the “Sulfide-Poor Platinum-Group Metal Ores” of the Norilsk-1 Intrusion (Northern Siberia, Russia) |
title_fullStr |
In-Situ Crystallization and Continuous Modification of Chromian Spinel in the “Sulfide-Poor Platinum-Group Metal Ores” of the Norilsk-1 Intrusion (Northern Siberia, Russia) |
title_full_unstemmed |
In-Situ Crystallization and Continuous Modification of Chromian Spinel in the “Sulfide-Poor Platinum-Group Metal Ores” of the Norilsk-1 Intrusion (Northern Siberia, Russia) |
title_sort |
in-situ crystallization and continuous modification of chromian spinel in the “sulfide-poor platinum-group metal ores” of the norilsk-1 intrusion (northern siberia, russia) |
publisher |
Multidisciplinary Digital Publishing Institute |
publishDate |
2020 |
url |
https://doi.org/10.3390/min10060498 |
op_coverage |
agris |
long_lat |
ENVELOPE(88.203,88.203,69.354,69.354) |
geographic |
Norilsk |
geographic_facet |
Norilsk |
genre |
norilsk Siberia |
genre_facet |
norilsk Siberia |
op_source |
Minerals; Volume 10; Issue 6; Pages: 498 |
op_relation |
Crystallography and Physical Chemistry of Minerals & Nanominerals https://dx.doi.org/10.3390/min10060498 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3390/min10060498 |
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Minerals |
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10 |
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6 |
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498 |
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