Geochemical Systematics of High Arctic Large Igneous Province Continental Tholeiites from Canada-Evidence for Progressive Crustal Contamination in the Plumbing System
Cretaceous High Arctic large igneous province (HALIP) sub-alkaline magmatic rocks in Canada are mostly evolved (MgO 2-7 wt%), sparsely plagioclase + clinopyroxene +/- olivine-phyric tholeiitic basalts. There were two main HALIP continental flood basalt (CFB) eruption episodes: 135-120 Ma (Isachsen F...
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Uppsala universitet, Mineralogi, petrologi och tektonik
2021
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ftuppsalauniv:oai:DiVA.org:uu-458479 2024-02-11T10:01:11+01:00 Geochemical Systematics of High Arctic Large Igneous Province Continental Tholeiites from Canada-Evidence for Progressive Crustal Contamination in the Plumbing System Bedard, Jean H. Saumur, Benoit Michel Tegner, Christian Troll, Valentin R. Deegan, Frances Evenchick, Carol A. Grasby, Stephen E. Dewing, Keith 2021 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-458479 https://doi.org/10.1093/petrology/egab041 eng eng Uppsala universitet, Mineralogi, petrologi och tektonik Uppsala universitet, Naturresurser och hållbar utveckling Geol Survey Canada, 490 Couronne, Quebec City, PQ G1K 9A9, Canada. Univ Quebec Montreal, Dept Sci Terre & Atmosphere, 201 Av President Kennedy, Montreal, PQ H2X 3Y7, Canada. Aarhus Univ, Ctr Earth Syst Petrol, Dept Geosci, Aarhus, Denmark. Geol Survey Canada, 605 Robson St, Vancouver, BC V6B 5J3, Canada. Geol Survey Canada, 3303 33Rd St Nw, Calgary, AB T2L 2A7, Canada. OXFORD UNIV PRESS Journal of Petrology, 0022-3530, 2021, 62:9, orcid:0000-0003-1891-3396 orcid:0000-0002-9065-9225 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-458479 doi:10.1093/petrology/egab041 ISI:000708732900004 info:eu-repo/semantics/openAccess basalt contamination continental LIP HALIP plumbing system Geology Geologi Article in journal info:eu-repo/semantics/article text 2021 ftuppsalauniv https://doi.org/10.1093/petrology/egab041 2024-01-17T23:32:25Z Cretaceous High Arctic large igneous province (HALIP) sub-alkaline magmatic rocks in Canada are mostly evolved (MgO 2-7 wt%), sparsely plagioclase + clinopyroxene +/- olivine-phyric tholeiitic basalts. There were two main HALIP continental flood basalt (CFB) eruption episodes: 135-120 Ma (Isachsen Fm.) and 105-90 Ma (Strand Fiord Fm.), both associated with cogenetic doleritic sills and dykes. Building on a large modern database, 16 HALIP tholeiite types are defined and grouped into genetic series using Ce vs Sm/Yb-NMORB distributions. Comparison with model melting curves implies that higher-Sm/Yb HALIP basalt types record low-degree melting of garnet-bearing mantle sources. More voluminous intermediate- and low-Sm/Yb HALIP basalt types separated from the mantle at shallower levels after further extensive melting in the spinel-peridotite field. Within a given Sm/Yb range, increases in incompatible elements such as Ce are coupled with progressive clockwise rotation of normalized incompatible trace element profiles. Trace element modeling implies this cannot be due to closed-system fractional crystallization but requires progressive and ubiquitous incorporation of a component resembling continental crust. The fractionation models imply that low-Sm/Yb HALIP basalts (similar to 7 wt% MgO) initially crystallized olivine gabbro assemblages, with lower-MgO basalts successively crystallizing gabbro and ilmenite-gabbro assemblages. In contrast, higher-Sm/Yb basalts fractionated more clinopyroxene and ilmenite, but extensive plagioclase fractionation is still required to explain developing negative Sr-Eu anomalies. Backfractionation models require about 40% addition of olivine to bring the most primitive HALIP basalts (similar to 7% MgO) into equilibrium with Fo(89) mantle. Inverse fractionation-assimilation modeling shrinks the CFB signature, making decontaminated model parental melts more similar to enriched mid-ocean ridge basalt. The progressive increase of the contamination signature within each HALIP tholeiitic ... Article in Journal/Newspaper Arctic Uppsala University: Publications (DiVA) Arctic Canada Isachsen ENVELOPE(-103.505,-103.505,78.785,78.785) Strand Fiord ENVELOPE(-91.468,-91.468,79.185,79.185) Journal of Petrology 62 9 |
institution |
Open Polar |
collection |
Uppsala University: Publications (DiVA) |
op_collection_id |
ftuppsalauniv |
language |
English |
topic |
basalt contamination continental LIP HALIP plumbing system Geology Geologi |
spellingShingle |
basalt contamination continental LIP HALIP plumbing system Geology Geologi Bedard, Jean H. Saumur, Benoit Michel Tegner, Christian Troll, Valentin R. Deegan, Frances Evenchick, Carol A. Grasby, Stephen E. Dewing, Keith Geochemical Systematics of High Arctic Large Igneous Province Continental Tholeiites from Canada-Evidence for Progressive Crustal Contamination in the Plumbing System |
topic_facet |
basalt contamination continental LIP HALIP plumbing system Geology Geologi |
description |
Cretaceous High Arctic large igneous province (HALIP) sub-alkaline magmatic rocks in Canada are mostly evolved (MgO 2-7 wt%), sparsely plagioclase + clinopyroxene +/- olivine-phyric tholeiitic basalts. There were two main HALIP continental flood basalt (CFB) eruption episodes: 135-120 Ma (Isachsen Fm.) and 105-90 Ma (Strand Fiord Fm.), both associated with cogenetic doleritic sills and dykes. Building on a large modern database, 16 HALIP tholeiite types are defined and grouped into genetic series using Ce vs Sm/Yb-NMORB distributions. Comparison with model melting curves implies that higher-Sm/Yb HALIP basalt types record low-degree melting of garnet-bearing mantle sources. More voluminous intermediate- and low-Sm/Yb HALIP basalt types separated from the mantle at shallower levels after further extensive melting in the spinel-peridotite field. Within a given Sm/Yb range, increases in incompatible elements such as Ce are coupled with progressive clockwise rotation of normalized incompatible trace element profiles. Trace element modeling implies this cannot be due to closed-system fractional crystallization but requires progressive and ubiquitous incorporation of a component resembling continental crust. The fractionation models imply that low-Sm/Yb HALIP basalts (similar to 7 wt% MgO) initially crystallized olivine gabbro assemblages, with lower-MgO basalts successively crystallizing gabbro and ilmenite-gabbro assemblages. In contrast, higher-Sm/Yb basalts fractionated more clinopyroxene and ilmenite, but extensive plagioclase fractionation is still required to explain developing negative Sr-Eu anomalies. Backfractionation models require about 40% addition of olivine to bring the most primitive HALIP basalts (similar to 7% MgO) into equilibrium with Fo(89) mantle. Inverse fractionation-assimilation modeling shrinks the CFB signature, making decontaminated model parental melts more similar to enriched mid-ocean ridge basalt. The progressive increase of the contamination signature within each HALIP tholeiitic ... |
format |
Article in Journal/Newspaper |
author |
Bedard, Jean H. Saumur, Benoit Michel Tegner, Christian Troll, Valentin R. Deegan, Frances Evenchick, Carol A. Grasby, Stephen E. Dewing, Keith |
author_facet |
Bedard, Jean H. Saumur, Benoit Michel Tegner, Christian Troll, Valentin R. Deegan, Frances Evenchick, Carol A. Grasby, Stephen E. Dewing, Keith |
author_sort |
Bedard, Jean H. |
title |
Geochemical Systematics of High Arctic Large Igneous Province Continental Tholeiites from Canada-Evidence for Progressive Crustal Contamination in the Plumbing System |
title_short |
Geochemical Systematics of High Arctic Large Igneous Province Continental Tholeiites from Canada-Evidence for Progressive Crustal Contamination in the Plumbing System |
title_full |
Geochemical Systematics of High Arctic Large Igneous Province Continental Tholeiites from Canada-Evidence for Progressive Crustal Contamination in the Plumbing System |
title_fullStr |
Geochemical Systematics of High Arctic Large Igneous Province Continental Tholeiites from Canada-Evidence for Progressive Crustal Contamination in the Plumbing System |
title_full_unstemmed |
Geochemical Systematics of High Arctic Large Igneous Province Continental Tholeiites from Canada-Evidence for Progressive Crustal Contamination in the Plumbing System |
title_sort |
geochemical systematics of high arctic large igneous province continental tholeiites from canada-evidence for progressive crustal contamination in the plumbing system |
publisher |
Uppsala universitet, Mineralogi, petrologi och tektonik |
publishDate |
2021 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-458479 https://doi.org/10.1093/petrology/egab041 |
long_lat |
ENVELOPE(-103.505,-103.505,78.785,78.785) ENVELOPE(-91.468,-91.468,79.185,79.185) |
geographic |
Arctic Canada Isachsen Strand Fiord |
geographic_facet |
Arctic Canada Isachsen Strand Fiord |
genre |
Arctic |
genre_facet |
Arctic |
op_relation |
Journal of Petrology, 0022-3530, 2021, 62:9, orcid:0000-0003-1891-3396 orcid:0000-0002-9065-9225 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-458479 doi:10.1093/petrology/egab041 ISI:000708732900004 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1093/petrology/egab041 |
container_title |
Journal of Petrology |
container_volume |
62 |
container_issue |
9 |
_version_ |
1790596942003175424 |