Uranium-rich pyrochlores flrom the Iimaussaq complex, South Greenland
Uranium-bearing primary and secondary pyrochlore was found as accessory minerals in pegmatites and mineral veins in the kakortokite rocks of the Ilimaussaq complex in South Greenland. They contain between 7.70 and 17.79 wt.% UO 2 and have the compositional range: (Na 0.08-0.88 , Ca 0.90-0.26 Mn 0.00...
Published in: | Neues Jahrbuch für Mineralogie - Abhandlungen |
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2018
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Online Access: | https://orbit.dtu.dk/en/publications/9b4ae343-fdd8-4af3-9897-38919c290517 https://doi.org/10.1127/njma/2018/0114 |
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ftdtupubl:oai:pure.atira.dk:publications/9b4ae343-fdd8-4af3-9897-38919c290517 2023-05-15T16:28:30+02:00 Uranium-rich pyrochlores flrom the Iimaussaq complex, South Greenland Karup-Møller, Sven 2018 https://orbit.dtu.dk/en/publications/9b4ae343-fdd8-4af3-9897-38919c290517 https://doi.org/10.1127/njma/2018/0114 eng eng info:eu-repo/semantics/closedAccess Karup-Møller , S 2018 , ' Uranium-rich pyrochlores flrom the Iimaussaq complex, South Greenland ' , Neues Jahrbuch für Mineralogie - Abhandlungen / Journal of Mineralogy and Geochemistry , vol. 195 , no. 3 , pp. 177-190 . https://doi.org/10.1127/njma/2018/0114 article 2018 ftdtupubl https://doi.org/10.1127/njma/2018/0114 2023-01-12T00:10:00Z Uranium-bearing primary and secondary pyrochlore was found as accessory minerals in pegmatites and mineral veins in the kakortokite rocks of the Ilimaussaq complex in South Greenland. They contain between 7.70 and 17.79 wt.% UO 2 and have the compositional range: (Na 0.08-0.88 , Ca 0.90-0.26 Mn 0.00-0.02 REE 0.24-0.30 U 0.11-0.26 []( 0.15-0.63 ) Σ2.00 (Nb 1.42-1.67 Ti 0.47-0.30 Zr 0.00-0.02 Fe 0.00-0.10 Si 0.00-0.10 ) Σ2 O 6 (F 0.10-0.50 OH 0.17-0.73 [] 0.02-0.46 ) Σ1 with unoccupied positions in both the A and Y-sites. Deuteric alteration has resulted in the formation of secondary pyrochlores characterized by the almost total removal of Na but without significant change in the content of the other cations present, accompanied, either by depletion of OH in the Y-site or protonation. Its compositional range is: (Na 0.04-0.24 K 0.00-0.05 Ca 0.68.0.21 Mn 0.000.02 REE 0.19-0.31 U 0.11-0.25 [] 0.74.1.01 ) Σ2 (Nb 1.42-1.69 Ti 0.28-0.46 Zr 0.00-0.01 Fe 0.01-0.05 Si 0.00-0.11 ) Σ2 (O 5.78-6.03 [] 0.35-0.01 ) Σ6 F 0.16-0.44 • nH 2 O. Complete silicification (12.7-15.4 wt.% SiO 2 ) of some pyrochlore crystals is characterized by negative correlation between Si and (Nb+Ti) and has resulted in the following empirical composition (Na 0.04 Ca 0.23 Mn 0.05 Al 0.14 REE 0.37 U 0.10 ) Σ0.92 (Si 0.78 Nb 0.95 Ti Fe 3+ 0.07 ) Σ2.00 O 5.72 F 0.07 • nH 2 O. An unidentified Nb-U-Pb-REE mineral named Nb3 has the empirical composition: Ca 0.9 Fe 0.5 Mn 0.8 Pb 2.0 REE 1.4 Al 0.5 Si 6.2 U 1.0 (Nb 7.8 Ti 1.9 Zr 0.2 ) Σ10.0 F 0.1 (O,OH,H 2 O) n . Article in Journal/Newspaper Greenland Technical University of Denmark: DTU Orbit Greenland The ''Y'' ENVELOPE(-112.453,-112.453,57.591,57.591) Ilimaussaq ENVELOPE(-45.900,-45.900,60.983,60.983) Neues Jahrbuch für Mineralogie - Abhandlungen 195 3 177 190 |
institution |
Open Polar |
collection |
Technical University of Denmark: DTU Orbit |
op_collection_id |
ftdtupubl |
language |
English |
description |
Uranium-bearing primary and secondary pyrochlore was found as accessory minerals in pegmatites and mineral veins in the kakortokite rocks of the Ilimaussaq complex in South Greenland. They contain between 7.70 and 17.79 wt.% UO 2 and have the compositional range: (Na 0.08-0.88 , Ca 0.90-0.26 Mn 0.00-0.02 REE 0.24-0.30 U 0.11-0.26 []( 0.15-0.63 ) Σ2.00 (Nb 1.42-1.67 Ti 0.47-0.30 Zr 0.00-0.02 Fe 0.00-0.10 Si 0.00-0.10 ) Σ2 O 6 (F 0.10-0.50 OH 0.17-0.73 [] 0.02-0.46 ) Σ1 with unoccupied positions in both the A and Y-sites. Deuteric alteration has resulted in the formation of secondary pyrochlores characterized by the almost total removal of Na but without significant change in the content of the other cations present, accompanied, either by depletion of OH in the Y-site or protonation. Its compositional range is: (Na 0.04-0.24 K 0.00-0.05 Ca 0.68.0.21 Mn 0.000.02 REE 0.19-0.31 U 0.11-0.25 [] 0.74.1.01 ) Σ2 (Nb 1.42-1.69 Ti 0.28-0.46 Zr 0.00-0.01 Fe 0.01-0.05 Si 0.00-0.11 ) Σ2 (O 5.78-6.03 [] 0.35-0.01 ) Σ6 F 0.16-0.44 • nH 2 O. Complete silicification (12.7-15.4 wt.% SiO 2 ) of some pyrochlore crystals is characterized by negative correlation between Si and (Nb+Ti) and has resulted in the following empirical composition (Na 0.04 Ca 0.23 Mn 0.05 Al 0.14 REE 0.37 U 0.10 ) Σ0.92 (Si 0.78 Nb 0.95 Ti Fe 3+ 0.07 ) Σ2.00 O 5.72 F 0.07 • nH 2 O. An unidentified Nb-U-Pb-REE mineral named Nb3 has the empirical composition: Ca 0.9 Fe 0.5 Mn 0.8 Pb 2.0 REE 1.4 Al 0.5 Si 6.2 U 1.0 (Nb 7.8 Ti 1.9 Zr 0.2 ) Σ10.0 F 0.1 (O,OH,H 2 O) n . |
format |
Article in Journal/Newspaper |
author |
Karup-Møller, Sven |
spellingShingle |
Karup-Møller, Sven Uranium-rich pyrochlores flrom the Iimaussaq complex, South Greenland |
author_facet |
Karup-Møller, Sven |
author_sort |
Karup-Møller, Sven |
title |
Uranium-rich pyrochlores flrom the Iimaussaq complex, South Greenland |
title_short |
Uranium-rich pyrochlores flrom the Iimaussaq complex, South Greenland |
title_full |
Uranium-rich pyrochlores flrom the Iimaussaq complex, South Greenland |
title_fullStr |
Uranium-rich pyrochlores flrom the Iimaussaq complex, South Greenland |
title_full_unstemmed |
Uranium-rich pyrochlores flrom the Iimaussaq complex, South Greenland |
title_sort |
uranium-rich pyrochlores flrom the iimaussaq complex, south greenland |
publishDate |
2018 |
url |
https://orbit.dtu.dk/en/publications/9b4ae343-fdd8-4af3-9897-38919c290517 https://doi.org/10.1127/njma/2018/0114 |
long_lat |
ENVELOPE(-112.453,-112.453,57.591,57.591) ENVELOPE(-45.900,-45.900,60.983,60.983) |
geographic |
Greenland The ''Y'' Ilimaussaq |
geographic_facet |
Greenland The ''Y'' Ilimaussaq |
genre |
Greenland |
genre_facet |
Greenland |
op_source |
Karup-Møller , S 2018 , ' Uranium-rich pyrochlores flrom the Iimaussaq complex, South Greenland ' , Neues Jahrbuch für Mineralogie - Abhandlungen / Journal of Mineralogy and Geochemistry , vol. 195 , no. 3 , pp. 177-190 . https://doi.org/10.1127/njma/2018/0114 |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.1127/njma/2018/0114 |
container_title |
Neues Jahrbuch für Mineralogie - Abhandlungen |
container_volume |
195 |
container_issue |
3 |
container_start_page |
177 |
op_container_end_page |
190 |
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1766018159609905152 |