Extreme enrichment of Se, Te, PGE and Au in Cu-sulfide microdroplets: evidence from LA-ICP-MS analysis of sulfides in the Skaergaard Intrusion, east Greenland
The Platinova Reef, in the Skaergaard Intrusion, east Greenland, is an example of a magmatic Cu–PGE–Au sulfide deposit formed in the latter stages of magmatic differentiation. As is characteristic with such deposits, it contains a low volume of sulfide, displays peak metal offsets and is Cu rich but...
Published in: | Contributions to Mineralogy and Petrology |
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Springer Verlag
2015
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ftunivcardiff:oai:https://orca.cardiff.ac.uk:81251 2023-05-15T16:03:45+02:00 Extreme enrichment of Se, Te, PGE and Au in Cu-sulfide microdroplets: evidence from LA-ICP-MS analysis of sulfides in the Skaergaard Intrusion, east Greenland Holwell, David A. Keays, Reid R. McDonald, Iain Williams, Megan R. 2015-11-25 application/pdf https://orca.cardiff.ac.uk/id/eprint/81251/ https://doi.org/10.1007/s00410-015-1203-y https://orca.cardiff.ac.uk/id/eprint/81251/8/art%253A10.1007%252Fs00410-015-1203-y.pdf en eng Springer Verlag https://orca.cardiff.ac.uk/id/eprint/81251/8/art%253A10.1007%252Fs00410-015-1203-y.pdf Holwell, David A., Keays, Reid R., McDonald, Iain https://orca.cardiff.ac.uk/view/cardiffauthors/A0179053.html orcid:0000-0001-9066-7244 orcid:0000-0001-9066-7244 and Williams, Megan R. 2015. Extreme enrichment of Se, Te, PGE and Au in Cu-sulfide microdroplets: evidence from LA-ICP-MS analysis of sulfides in the Skaergaard Intrusion, east Greenland. Contributions to Mineralogy and Petrology 170 , 53. 10.1007/s00410-015-1203-y https://doi.org/10.1007/s00410-015-1203-y file https://orca.cardiff.ac.uk/81251/8/art%253A10.1007%252Fs00410-015-1203-y.pdf doi:10.1007/s00410-015-1203-y cc_by CC-BY QE Geology Article PeerReviewed 2015 ftunivcardiff https://doi.org/10.1007/s00410-015-1203-y 2022-11-03T23:35:41Z The Platinova Reef, in the Skaergaard Intrusion, east Greenland, is an example of a magmatic Cu–PGE–Au sulfide deposit formed in the latter stages of magmatic differentiation. As is characteristic with such deposits, it contains a low volume of sulfide, displays peak metal offsets and is Cu rich but Ni poor. However, even for such deposits, the Platinova Reef contains extremely low volumes of sulfide and the highest Pd and Au tenor sulfides of any magmatic ore deposit. Here, we present the first LA-ICP-MS analyses of sulfide microdroplets from the Platinova Reef, which show that they have the highest Se concentrations (up to 1200 ppm) and lowest S/Se ratios (190–700) of any known magmatic sulfide deposit and have significant Te enrichment. In addition, where sulfide volume increases, there is a change from high Pd-tenor microdroplets trapped in situ to larger, low tenor sulfides. The transition between these two sulfide regimes is marked by sharp peaks in Au, and then Te concentration, followed by a wider peak in Se, which gradually decreases with height. Mineralogical evidence implies that there is no significant post-magmatic hydrothermal S loss and that the metal profiles are essentially a function of magmatic processes. We propose that to generate these extreme precious and semimetal contents, the sulfides must have formed from an anomalously metal-rich package of magma, possibly formed via the dissolution of a previously PGE-enriched sulfide. Other processes such as kinetic diffusion may have also occurred alongside this to produce the ultra-high tenors. The characteristic metal offset pattern observed is largely controlled by partitioning effects, producing offset peaks in the order Pt+Pd>Au>Te>Se>Cu that are entirely consistent with published D values. This study confirms that extreme enrichment in sulfide droplets can occur in closed-system layered intrusions in situ, but this will characteristically form ore deposits that are so low in sulfide that they do not conform to conventional deposit ... Article in Journal/Newspaper East Greenland Greenland Cardiff University: ORCA (Online Research @ Cardiff) Greenland Contributions to Mineralogy and Petrology 170 5-6 |
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Open Polar |
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Cardiff University: ORCA (Online Research @ Cardiff) |
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ftunivcardiff |
language |
English |
topic |
QE Geology |
spellingShingle |
QE Geology Holwell, David A. Keays, Reid R. McDonald, Iain Williams, Megan R. Extreme enrichment of Se, Te, PGE and Au in Cu-sulfide microdroplets: evidence from LA-ICP-MS analysis of sulfides in the Skaergaard Intrusion, east Greenland |
topic_facet |
QE Geology |
description |
The Platinova Reef, in the Skaergaard Intrusion, east Greenland, is an example of a magmatic Cu–PGE–Au sulfide deposit formed in the latter stages of magmatic differentiation. As is characteristic with such deposits, it contains a low volume of sulfide, displays peak metal offsets and is Cu rich but Ni poor. However, even for such deposits, the Platinova Reef contains extremely low volumes of sulfide and the highest Pd and Au tenor sulfides of any magmatic ore deposit. Here, we present the first LA-ICP-MS analyses of sulfide microdroplets from the Platinova Reef, which show that they have the highest Se concentrations (up to 1200 ppm) and lowest S/Se ratios (190–700) of any known magmatic sulfide deposit and have significant Te enrichment. In addition, where sulfide volume increases, there is a change from high Pd-tenor microdroplets trapped in situ to larger, low tenor sulfides. The transition between these two sulfide regimes is marked by sharp peaks in Au, and then Te concentration, followed by a wider peak in Se, which gradually decreases with height. Mineralogical evidence implies that there is no significant post-magmatic hydrothermal S loss and that the metal profiles are essentially a function of magmatic processes. We propose that to generate these extreme precious and semimetal contents, the sulfides must have formed from an anomalously metal-rich package of magma, possibly formed via the dissolution of a previously PGE-enriched sulfide. Other processes such as kinetic diffusion may have also occurred alongside this to produce the ultra-high tenors. The characteristic metal offset pattern observed is largely controlled by partitioning effects, producing offset peaks in the order Pt+Pd>Au>Te>Se>Cu that are entirely consistent with published D values. This study confirms that extreme enrichment in sulfide droplets can occur in closed-system layered intrusions in situ, but this will characteristically form ore deposits that are so low in sulfide that they do not conform to conventional deposit ... |
format |
Article in Journal/Newspaper |
author |
Holwell, David A. Keays, Reid R. McDonald, Iain Williams, Megan R. |
author_facet |
Holwell, David A. Keays, Reid R. McDonald, Iain Williams, Megan R. |
author_sort |
Holwell, David A. |
title |
Extreme enrichment of Se, Te, PGE and Au in Cu-sulfide microdroplets: evidence from LA-ICP-MS analysis of sulfides in the Skaergaard Intrusion, east Greenland |
title_short |
Extreme enrichment of Se, Te, PGE and Au in Cu-sulfide microdroplets: evidence from LA-ICP-MS analysis of sulfides in the Skaergaard Intrusion, east Greenland |
title_full |
Extreme enrichment of Se, Te, PGE and Au in Cu-sulfide microdroplets: evidence from LA-ICP-MS analysis of sulfides in the Skaergaard Intrusion, east Greenland |
title_fullStr |
Extreme enrichment of Se, Te, PGE and Au in Cu-sulfide microdroplets: evidence from LA-ICP-MS analysis of sulfides in the Skaergaard Intrusion, east Greenland |
title_full_unstemmed |
Extreme enrichment of Se, Te, PGE and Au in Cu-sulfide microdroplets: evidence from LA-ICP-MS analysis of sulfides in the Skaergaard Intrusion, east Greenland |
title_sort |
extreme enrichment of se, te, pge and au in cu-sulfide microdroplets: evidence from la-icp-ms analysis of sulfides in the skaergaard intrusion, east greenland |
publisher |
Springer Verlag |
publishDate |
2015 |
url |
https://orca.cardiff.ac.uk/id/eprint/81251/ https://doi.org/10.1007/s00410-015-1203-y https://orca.cardiff.ac.uk/id/eprint/81251/8/art%253A10.1007%252Fs00410-015-1203-y.pdf |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
East Greenland Greenland |
genre_facet |
East Greenland Greenland |
op_relation |
https://orca.cardiff.ac.uk/id/eprint/81251/8/art%253A10.1007%252Fs00410-015-1203-y.pdf Holwell, David A., Keays, Reid R., McDonald, Iain https://orca.cardiff.ac.uk/view/cardiffauthors/A0179053.html orcid:0000-0001-9066-7244 orcid:0000-0001-9066-7244 and Williams, Megan R. 2015. Extreme enrichment of Se, Te, PGE and Au in Cu-sulfide microdroplets: evidence from LA-ICP-MS analysis of sulfides in the Skaergaard Intrusion, east Greenland. Contributions to Mineralogy and Petrology 170 , 53. 10.1007/s00410-015-1203-y https://doi.org/10.1007/s00410-015-1203-y file https://orca.cardiff.ac.uk/81251/8/art%253A10.1007%252Fs00410-015-1203-y.pdf doi:10.1007/s00410-015-1203-y |
op_rights |
cc_by |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1007/s00410-015-1203-y |
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Contributions to Mineralogy and Petrology |
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170 |
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