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 Fm....
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2021
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Online Access: | https://pure.au.dk/portal/da/publications/geochemical-systematics-of-high-arctic-large-igneous-province-continental-tholeiites-from-canada--evidence-for-progressive-crustal-contamination-in-the-plumbing-system(e9c25a05-2157-4e44-b66d-5cf99be74cf7).html https://doi.org/10.1093/petrology/egab041 http://www.scopus.com/inward/record.url?scp=85117376653&partnerID=8YFLogxK |
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ftuniaarhuspubl:oai:pure.atira.dk:publications/e9c25a05-2157-4e44-b66d-5cf99be74cf7 2023-11-12T04:09:50+01:00 Geochemical Systematics of High Arctic Large Igneous Province Continental Tholeiites from Canada - Evidence for Progressive Crustal Contamination in the Plumbing System Bédard, Jean H. Saumur, Benoit Michel Tegner, Christian Troll, Valentin R. Deegan, Frances M. Evenchick, Carol A. Grasby, Stephen E. Dewing, Keith 2021-09 https://pure.au.dk/portal/da/publications/geochemical-systematics-of-high-arctic-large-igneous-province-continental-tholeiites-from-canada--evidence-for-progressive-crustal-contamination-in-the-plumbing-system(e9c25a05-2157-4e44-b66d-5cf99be74cf7).html https://doi.org/10.1093/petrology/egab041 http://www.scopus.com/inward/record.url?scp=85117376653&partnerID=8YFLogxK eng eng https://pure.au.dk/portal/da/publications/geochemical-systematics-of-high-arctic-large-igneous-province-continental-tholeiites-from-canada--evidence-for-progressive-crustal-contamination-in-the-plumbing-system(e9c25a05-2157-4e44-b66d-5cf99be74cf7).html info:eu-repo/semantics/openAccess Bédard , J H , Saumur , B M , Tegner , C , Troll , V R , Deegan , F M , Evenchick , C A , Grasby , S E & Dewing , K 2021 , ' Geochemical Systematics of High Arctic Large Igneous Province Continental Tholeiites from Canada - Evidence for Progressive Crustal Contamination in the Plumbing System ' , Journal of Petrology , vol. 62 , no. 9 , egab041 . https://doi.org/10.1093/petrology/egab041 basalt contamination continental LIP HALIP plumbing system article 2021 ftuniaarhuspubl https://doi.org/10.1093/petrology/egab041 2023-10-25T23:00:32Z 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/YbNMORB 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 (∼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. Back-fractionation models require about 40 % addition of olivine to bring the most primitive HALIP basalts (∼7 % MgO) into equilibrium with Fo89 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 differentiation series is ... Article in Journal/Newspaper Arctic Arctic Aarhus University: Research 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 |
Aarhus University: Research |
op_collection_id |
ftuniaarhuspubl |
language |
English |
topic |
basalt contamination continental LIP HALIP plumbing system |
spellingShingle |
basalt contamination continental LIP HALIP plumbing system Bédard, Jean H. Saumur, Benoit Michel Tegner, Christian Troll, Valentin R. Deegan, Frances M. 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 |
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/YbNMORB 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 (∼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. Back-fractionation models require about 40 % addition of olivine to bring the most primitive HALIP basalts (∼7 % MgO) into equilibrium with Fo89 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 differentiation series is ... |
format |
Article in Journal/Newspaper |
author |
Bédard, Jean H. Saumur, Benoit Michel Tegner, Christian Troll, Valentin R. Deegan, Frances M. Evenchick, Carol A. Grasby, Stephen E. Dewing, Keith |
author_facet |
Bédard, Jean H. Saumur, Benoit Michel Tegner, Christian Troll, Valentin R. Deegan, Frances M. Evenchick, Carol A. Grasby, Stephen E. Dewing, Keith |
author_sort |
Bédard, 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 |
publishDate |
2021 |
url |
https://pure.au.dk/portal/da/publications/geochemical-systematics-of-high-arctic-large-igneous-province-continental-tholeiites-from-canada--evidence-for-progressive-crustal-contamination-in-the-plumbing-system(e9c25a05-2157-4e44-b66d-5cf99be74cf7).html https://doi.org/10.1093/petrology/egab041 http://www.scopus.com/inward/record.url?scp=85117376653&partnerID=8YFLogxK |
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 Arctic |
genre_facet |
Arctic Arctic |
op_source |
Bédard , J H , Saumur , B M , Tegner , C , Troll , V R , Deegan , F M , Evenchick , C A , Grasby , S E & Dewing , K 2021 , ' Geochemical Systematics of High Arctic Large Igneous Province Continental Tholeiites from Canada - Evidence for Progressive Crustal Contamination in the Plumbing System ' , Journal of Petrology , vol. 62 , no. 9 , egab041 . https://doi.org/10.1093/petrology/egab041 |
op_relation |
https://pure.au.dk/portal/da/publications/geochemical-systematics-of-high-arctic-large-igneous-province-continental-tholeiites-from-canada--evidence-for-progressive-crustal-contamination-in-the-plumbing-system(e9c25a05-2157-4e44-b66d-5cf99be74cf7).html |
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 |
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1782329621292777472 |