Platinum-group mineralization at the margin of the Skaergaard intrusion, East Greenland
Two occurrences of platinum-group elements (PGEs) along the northern margin of the Skaergaard intrusion include a sulfide-bearing gabbro with slightly less than 1 ppm PGE + Au and a clinopyroxene-actinolite-plagioclase-biotite-ilmenite schist with 16 vol% sulfide and 1.8 ppm PGE + Au. Both have asse...
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2017
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ftuniaarhuspubl:oai:pure.atira.dk:publications/1a63ce49-3669-4220-ad73-47bbb54184fa 2023-05-15T16:03:53+02:00 Platinum-group mineralization at the margin of the Skaergaard intrusion, East Greenland Andersen, Jens C Ø Rollinson, Gavyn K. McDonald, Iain Tegner, Christian Lesher, Charles E. 2017-08 application/pdf https://pure.au.dk/portal/da/publications/platinumgroup-mineralization-at-the-margin-of-the-skaergaard-intrusion-east-greenland(1a63ce49-3669-4220-ad73-47bbb54184fa).html https://doi.org/10.1007/s00126-016-0707-3 https://pure.au.dk/ws/files/118819243/s00126_016_0707_3.pdf eng eng info:eu-repo/semantics/openAccess Andersen , J C Ø , Rollinson , G K , McDonald , I , Tegner , C & Lesher , C E 2017 , ' Platinum-group mineralization at the margin of the Skaergaard intrusion, East Greenland ' , Mineralium Deposita , vol. 52 , no. 6 , pp. 929–942 . https://doi.org/10.1007/s00126-016-0707-3 Greenland Platinum-group elements Skaergaard intrusion article 2017 ftuniaarhuspubl https://doi.org/10.1007/s00126-016-0707-3 2023-01-18T23:55:08Z Two occurrences of platinum-group elements (PGEs) along the northern margin of the Skaergaard intrusion include a sulfide-bearing gabbro with slightly less than 1 ppm PGE + Au and a clinopyroxene-actinolite-plagioclase-biotite-ilmenite schist with 16 vol% sulfide and 1.8 ppm PGE + Au. Both have assemblages of pyrrhotite, pentlandite, and chalcopyrite typical for orthomagmatic sulfides. Matching platinum-group mineral assemblages with sperrylite (PtAs 2 ), kotulskite (Pd(Bi,Te) 1–2 ), froodite (PdBi 2 ), michenerite (PdBiTe), and electrum (Au,Ag) suggest a common origin. Petrological and geochemical similarities suggest that the occurrences are related to the Skaergaard intrusion. The Marginal Border Series locally displays Ni depletion consistent with sulfide fractionation, and the PGE fractionation trends of the occurrences are systematically enriched by 10–50 times over the chilled margin. The PGE can be explained by sulfide-silicate immiscibility in the Skaergaard magma with R factors of 110–220. Nickel depletion in olivine suggests that the process occurred within the host cumulate, and the low R factors require little sulfide mobility. The sulfide assemblages are different to the chalcopyrite-bornite-digenite assemblage found in the Skaergaard Layered Series and Platinova Reef. These differences can be explained by the early formation of sulfide melt, while magmatic differentiation or sulfur loss caused the unusual sulfide assemblage within the Layered Series. The PGEs indicate that the sulfides formed from the Skaergaard magma. The sulfides and PGEs could not have formed from the nearby Watkins Fjord wehrlite intrusion, which is nearly barren in sulfide. We suggest that silicate-sulfide immiscibility led to PGE concentration where the Skaergaard magma became contaminated with material from the Archean basement. Article in Journal/Newspaper East Greenland Greenland Aarhus University: Research Greenland Watkins ENVELOPE(-67.086,-67.086,-66.354,-66.354) Watkins Fjord ENVELOPE(-31.811,-31.811,68.263,68.263) Mineralium Deposita 52 6 929 942 |
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Open Polar |
collection |
Aarhus University: Research |
op_collection_id |
ftuniaarhuspubl |
language |
English |
topic |
Greenland Platinum-group elements Skaergaard intrusion |
spellingShingle |
Greenland Platinum-group elements Skaergaard intrusion Andersen, Jens C Ø Rollinson, Gavyn K. McDonald, Iain Tegner, Christian Lesher, Charles E. Platinum-group mineralization at the margin of the Skaergaard intrusion, East Greenland |
topic_facet |
Greenland Platinum-group elements Skaergaard intrusion |
description |
Two occurrences of platinum-group elements (PGEs) along the northern margin of the Skaergaard intrusion include a sulfide-bearing gabbro with slightly less than 1 ppm PGE + Au and a clinopyroxene-actinolite-plagioclase-biotite-ilmenite schist with 16 vol% sulfide and 1.8 ppm PGE + Au. Both have assemblages of pyrrhotite, pentlandite, and chalcopyrite typical for orthomagmatic sulfides. Matching platinum-group mineral assemblages with sperrylite (PtAs 2 ), kotulskite (Pd(Bi,Te) 1–2 ), froodite (PdBi 2 ), michenerite (PdBiTe), and electrum (Au,Ag) suggest a common origin. Petrological and geochemical similarities suggest that the occurrences are related to the Skaergaard intrusion. The Marginal Border Series locally displays Ni depletion consistent with sulfide fractionation, and the PGE fractionation trends of the occurrences are systematically enriched by 10–50 times over the chilled margin. The PGE can be explained by sulfide-silicate immiscibility in the Skaergaard magma with R factors of 110–220. Nickel depletion in olivine suggests that the process occurred within the host cumulate, and the low R factors require little sulfide mobility. The sulfide assemblages are different to the chalcopyrite-bornite-digenite assemblage found in the Skaergaard Layered Series and Platinova Reef. These differences can be explained by the early formation of sulfide melt, while magmatic differentiation or sulfur loss caused the unusual sulfide assemblage within the Layered Series. The PGEs indicate that the sulfides formed from the Skaergaard magma. The sulfides and PGEs could not have formed from the nearby Watkins Fjord wehrlite intrusion, which is nearly barren in sulfide. We suggest that silicate-sulfide immiscibility led to PGE concentration where the Skaergaard magma became contaminated with material from the Archean basement. |
format |
Article in Journal/Newspaper |
author |
Andersen, Jens C Ø Rollinson, Gavyn K. McDonald, Iain Tegner, Christian Lesher, Charles E. |
author_facet |
Andersen, Jens C Ø Rollinson, Gavyn K. McDonald, Iain Tegner, Christian Lesher, Charles E. |
author_sort |
Andersen, Jens C Ø |
title |
Platinum-group mineralization at the margin of the Skaergaard intrusion, East Greenland |
title_short |
Platinum-group mineralization at the margin of the Skaergaard intrusion, East Greenland |
title_full |
Platinum-group mineralization at the margin of the Skaergaard intrusion, East Greenland |
title_fullStr |
Platinum-group mineralization at the margin of the Skaergaard intrusion, East Greenland |
title_full_unstemmed |
Platinum-group mineralization at the margin of the Skaergaard intrusion, East Greenland |
title_sort |
platinum-group mineralization at the margin of the skaergaard intrusion, east greenland |
publishDate |
2017 |
url |
https://pure.au.dk/portal/da/publications/platinumgroup-mineralization-at-the-margin-of-the-skaergaard-intrusion-east-greenland(1a63ce49-3669-4220-ad73-47bbb54184fa).html https://doi.org/10.1007/s00126-016-0707-3 https://pure.au.dk/ws/files/118819243/s00126_016_0707_3.pdf |
long_lat |
ENVELOPE(-67.086,-67.086,-66.354,-66.354) ENVELOPE(-31.811,-31.811,68.263,68.263) |
geographic |
Greenland Watkins Watkins Fjord |
geographic_facet |
Greenland Watkins Watkins Fjord |
genre |
East Greenland Greenland |
genre_facet |
East Greenland Greenland |
op_source |
Andersen , J C Ø , Rollinson , G K , McDonald , I , Tegner , C & Lesher , C E 2017 , ' Platinum-group mineralization at the margin of the Skaergaard intrusion, East Greenland ' , Mineralium Deposita , vol. 52 , no. 6 , pp. 929–942 . https://doi.org/10.1007/s00126-016-0707-3 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1007/s00126-016-0707-3 |
container_title |
Mineralium Deposita |
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52 |
container_issue |
6 |
container_start_page |
929 |
op_container_end_page |
942 |
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1766399580290678784 |