Ti-Rich Tholeiitic Picrites from the Prinsen af Wales Bjerge, East Greenland, and Evidence for a Pyroxene-Rich Mantle Source at Breakup in the North Atlantic
Abstract Highly magnesian, olivine-phyric tholeiitic basaltic and picritic lavas with >5 wt% TiO2 from the Prinsen af Wales Bjerge (PAWB) region are chemically distinct from all other Paleogene East Greenland flood basalts and from basalts in the North Atlantic Igneous Province. The ~100-m-th...
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Language: | English |
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Oxford University Press (OUP)
2022
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Online Access: | http://dx.doi.org/10.1093/petrology/egac078 https://academic.oup.com/petrology/advance-article-pdf/doi/10.1093/petrology/egac078/45250740/egac078.pdf https://academic.oup.com/petrology/article-pdf/63/8/egac078/45609293/egac078.pdf |
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croxfordunivpr:10.1093/petrology/egac078 2023-05-15T16:03:32+02:00 Ti-Rich Tholeiitic Picrites from the Prinsen af Wales Bjerge, East Greenland, and Evidence for a Pyroxene-Rich Mantle Source at Breakup in the North Atlantic Hansen, Henriette Nielsen, Troels F D 2022 http://dx.doi.org/10.1093/petrology/egac078 https://academic.oup.com/petrology/advance-article-pdf/doi/10.1093/petrology/egac078/45250740/egac078.pdf https://academic.oup.com/petrology/article-pdf/63/8/egac078/45609293/egac078.pdf en eng Oxford University Press (OUP) https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model Journal of Petrology volume 63, issue 8 ISSN 0022-3530 1460-2415 Geochemistry and Petrology Geophysics journal-article 2022 croxfordunivpr https://doi.org/10.1093/petrology/egac078 2022-09-02T09:23:42Z Abstract Highly magnesian, olivine-phyric tholeiitic basaltic and picritic lavas with >5 wt% TiO2 from the Prinsen af Wales Bjerge (PAWB) region are chemically distinct from all other Paleogene East Greenland flood basalts and from basalts in the North Atlantic Igneous Province. The ~100-m-thick lava succession rests on the 61 Ma Urbjerget Formation, is intercalated with volcaniclastic sediments, and has 57 Ma 40Ar/39Ar stepwise degassing ages. It is part of the Milne Land Formation, the first of the major flood basalt formations in East Greenland, and the result of plume impingement of the Kangerlussuaq area in East Greenland during the initial stages of continental breakup. The Ti-rich picrites have relatively primitive compositions and contain Mn- and Ni-rich olivine up to Fo88. Intermediate to high 87Sr/86Sri (0.7034–0.7044) and low Pb isotopic compositions reflect 4–11% crustal contamination, whereas the initial εNd (+4 − +5) and 187Os/188Os ratios (0.121–0.129) overlap with recent Icelandic basalts and appear little affected by contamination processes. The mantle source of the Ti-rich picrites contained garnet and was pyroxene-rich and similar to that of later low-Si alkaline basalts. The Ti-rich picrites of the PAWB, similar to other Ti-rich melts of the Kangerlussuaq region, represent analogies of MgO-rich and variably TiO2-enriched melts from pyroxene rich sources of traditionally accepted mantle plumes like Hawaii. Article in Journal/Newspaper East Greenland Greenland Kangerlussuaq Milne Land North Atlantic Oxford University Press (via Crossref) Greenland Kangerlussuaq ENVELOPE(-55.633,-55.633,72.633,72.633) Milne Land ENVELOPE(-26.750,-26.750,70.683,70.683) Prinsen ENVELOPE(21.494,21.494,69.991,69.991) Prinsen af Wales Bjerge ENVELOPE(-32.667,-32.667,68.933,68.933) Urbjerget ENVELOPE(-32.617,-32.617,68.817,68.817) Journal of Petrology 63 8 |
institution |
Open Polar |
collection |
Oxford University Press (via Crossref) |
op_collection_id |
croxfordunivpr |
language |
English |
topic |
Geochemistry and Petrology Geophysics |
spellingShingle |
Geochemistry and Petrology Geophysics Hansen, Henriette Nielsen, Troels F D Ti-Rich Tholeiitic Picrites from the Prinsen af Wales Bjerge, East Greenland, and Evidence for a Pyroxene-Rich Mantle Source at Breakup in the North Atlantic |
topic_facet |
Geochemistry and Petrology Geophysics |
description |
Abstract Highly magnesian, olivine-phyric tholeiitic basaltic and picritic lavas with >5 wt% TiO2 from the Prinsen af Wales Bjerge (PAWB) region are chemically distinct from all other Paleogene East Greenland flood basalts and from basalts in the North Atlantic Igneous Province. The ~100-m-thick lava succession rests on the 61 Ma Urbjerget Formation, is intercalated with volcaniclastic sediments, and has 57 Ma 40Ar/39Ar stepwise degassing ages. It is part of the Milne Land Formation, the first of the major flood basalt formations in East Greenland, and the result of plume impingement of the Kangerlussuaq area in East Greenland during the initial stages of continental breakup. The Ti-rich picrites have relatively primitive compositions and contain Mn- and Ni-rich olivine up to Fo88. Intermediate to high 87Sr/86Sri (0.7034–0.7044) and low Pb isotopic compositions reflect 4–11% crustal contamination, whereas the initial εNd (+4 − +5) and 187Os/188Os ratios (0.121–0.129) overlap with recent Icelandic basalts and appear little affected by contamination processes. The mantle source of the Ti-rich picrites contained garnet and was pyroxene-rich and similar to that of later low-Si alkaline basalts. The Ti-rich picrites of the PAWB, similar to other Ti-rich melts of the Kangerlussuaq region, represent analogies of MgO-rich and variably TiO2-enriched melts from pyroxene rich sources of traditionally accepted mantle plumes like Hawaii. |
format |
Article in Journal/Newspaper |
author |
Hansen, Henriette Nielsen, Troels F D |
author_facet |
Hansen, Henriette Nielsen, Troels F D |
author_sort |
Hansen, Henriette |
title |
Ti-Rich Tholeiitic Picrites from the Prinsen af Wales Bjerge, East Greenland, and Evidence for a Pyroxene-Rich Mantle Source at Breakup in the North Atlantic |
title_short |
Ti-Rich Tholeiitic Picrites from the Prinsen af Wales Bjerge, East Greenland, and Evidence for a Pyroxene-Rich Mantle Source at Breakup in the North Atlantic |
title_full |
Ti-Rich Tholeiitic Picrites from the Prinsen af Wales Bjerge, East Greenland, and Evidence for a Pyroxene-Rich Mantle Source at Breakup in the North Atlantic |
title_fullStr |
Ti-Rich Tholeiitic Picrites from the Prinsen af Wales Bjerge, East Greenland, and Evidence for a Pyroxene-Rich Mantle Source at Breakup in the North Atlantic |
title_full_unstemmed |
Ti-Rich Tholeiitic Picrites from the Prinsen af Wales Bjerge, East Greenland, and Evidence for a Pyroxene-Rich Mantle Source at Breakup in the North Atlantic |
title_sort |
ti-rich tholeiitic picrites from the prinsen af wales bjerge, east greenland, and evidence for a pyroxene-rich mantle source at breakup in the north atlantic |
publisher |
Oxford University Press (OUP) |
publishDate |
2022 |
url |
http://dx.doi.org/10.1093/petrology/egac078 https://academic.oup.com/petrology/advance-article-pdf/doi/10.1093/petrology/egac078/45250740/egac078.pdf https://academic.oup.com/petrology/article-pdf/63/8/egac078/45609293/egac078.pdf |
long_lat |
ENVELOPE(-55.633,-55.633,72.633,72.633) ENVELOPE(-26.750,-26.750,70.683,70.683) ENVELOPE(21.494,21.494,69.991,69.991) ENVELOPE(-32.667,-32.667,68.933,68.933) ENVELOPE(-32.617,-32.617,68.817,68.817) |
geographic |
Greenland Kangerlussuaq Milne Land Prinsen Prinsen af Wales Bjerge Urbjerget |
geographic_facet |
Greenland Kangerlussuaq Milne Land Prinsen Prinsen af Wales Bjerge Urbjerget |
genre |
East Greenland Greenland Kangerlussuaq Milne Land North Atlantic |
genre_facet |
East Greenland Greenland Kangerlussuaq Milne Land North Atlantic |
op_source |
Journal of Petrology volume 63, issue 8 ISSN 0022-3530 1460-2415 |
op_rights |
https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model |
op_doi |
https://doi.org/10.1093/petrology/egac078 |
container_title |
Journal of Petrology |
container_volume |
63 |
container_issue |
8 |
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1766399205061951488 |