The Nicola Group: Late Triassic and Early Jurassic subduction-related volcanism in British Columbia
Mafic lavas of the Nicola Group are divided into three distinct petrographic and geochemical types: type 1 lavas are strongly augite-porphyritic picrites, basalts, and andesites that belong to a high-potassium to shoshonitic rock series; type 2 lavas are augite- and plagioclase-porphyritic basalts a...
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1987
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crcansciencepubl:10.1139/e87-236 2023-12-17T10:29:22+01:00 The Nicola Group: Late Triassic and Early Jurassic subduction-related volcanism in British Columbia Mortimer, N. 1987 http://dx.doi.org/10.1139/e87-236 http://www.nrcresearchpress.com/doi/pdf/10.1139/e87-236 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 24, issue 12, page 2521-2536 ISSN 0008-4077 1480-3313 General Earth and Planetary Sciences journal-article 1987 crcansciencepubl https://doi.org/10.1139/e87-236 2023-11-19T13:38:15Z Mafic lavas of the Nicola Group are divided into three distinct petrographic and geochemical types: type 1 lavas are strongly augite-porphyritic picrites, basalts, and andesites that belong to a high-potassium to shoshonitic rock series; type 2 lavas are augite- and plagioclase-porphyritic basalts and andesites that belong to a low-potassium calc-alkaline series; and type 3 lavas are petrographically variable tholeiitic to transitional basalts and andesites.Low concentrations of Ti, Zr, Y, and Nb and moderate to high concentrations of K, Rb, Ba, and Sr in type 1 and 2 lavas clearly indicate a subduction-related tectonic setting of eruption. Type 3 lavas show chemical affinities intermediate between modern-day island-arc and intraplate volcanics. Type 1 (shoshonitic) lavas generally lie east of and are younger than type 2 (calc-alkaline) lavas, a relationship that implies an east-dipping early Mesozoic subduction zone beneath the Nicola arc. These interpretations resolve previous uncertainties regarding the tectonic setting of eruption of the Nicola Group.Several major 205–220 Ma plutons that intrude the Nicola Group crystallized from type 1 and 2 magmas and represent the final stages of Late Triassic to Early Jurassic arc-related igneous activity in southern Quesnellia. Article in Journal/Newspaper Day Island Canadian Science Publishing (via Crossref) Canadian Journal of Earth Sciences 24 12 2521 2536 |
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Open Polar |
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Canadian Science Publishing (via Crossref) |
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crcansciencepubl |
language |
English |
topic |
General Earth and Planetary Sciences |
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General Earth and Planetary Sciences Mortimer, N. The Nicola Group: Late Triassic and Early Jurassic subduction-related volcanism in British Columbia |
topic_facet |
General Earth and Planetary Sciences |
description |
Mafic lavas of the Nicola Group are divided into three distinct petrographic and geochemical types: type 1 lavas are strongly augite-porphyritic picrites, basalts, and andesites that belong to a high-potassium to shoshonitic rock series; type 2 lavas are augite- and plagioclase-porphyritic basalts and andesites that belong to a low-potassium calc-alkaline series; and type 3 lavas are petrographically variable tholeiitic to transitional basalts and andesites.Low concentrations of Ti, Zr, Y, and Nb and moderate to high concentrations of K, Rb, Ba, and Sr in type 1 and 2 lavas clearly indicate a subduction-related tectonic setting of eruption. Type 3 lavas show chemical affinities intermediate between modern-day island-arc and intraplate volcanics. Type 1 (shoshonitic) lavas generally lie east of and are younger than type 2 (calc-alkaline) lavas, a relationship that implies an east-dipping early Mesozoic subduction zone beneath the Nicola arc. These interpretations resolve previous uncertainties regarding the tectonic setting of eruption of the Nicola Group.Several major 205–220 Ma plutons that intrude the Nicola Group crystallized from type 1 and 2 magmas and represent the final stages of Late Triassic to Early Jurassic arc-related igneous activity in southern Quesnellia. |
format |
Article in Journal/Newspaper |
author |
Mortimer, N. |
author_facet |
Mortimer, N. |
author_sort |
Mortimer, N. |
title |
The Nicola Group: Late Triassic and Early Jurassic subduction-related volcanism in British Columbia |
title_short |
The Nicola Group: Late Triassic and Early Jurassic subduction-related volcanism in British Columbia |
title_full |
The Nicola Group: Late Triassic and Early Jurassic subduction-related volcanism in British Columbia |
title_fullStr |
The Nicola Group: Late Triassic and Early Jurassic subduction-related volcanism in British Columbia |
title_full_unstemmed |
The Nicola Group: Late Triassic and Early Jurassic subduction-related volcanism in British Columbia |
title_sort |
nicola group: late triassic and early jurassic subduction-related volcanism in british columbia |
publisher |
Canadian Science Publishing |
publishDate |
1987 |
url |
http://dx.doi.org/10.1139/e87-236 http://www.nrcresearchpress.com/doi/pdf/10.1139/e87-236 |
genre |
Day Island |
genre_facet |
Day Island |
op_source |
Canadian Journal of Earth Sciences volume 24, issue 12, page 2521-2536 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e87-236 |
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Canadian Journal of Earth Sciences |
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24 |
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12 |
container_start_page |
2521 |
op_container_end_page |
2536 |
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1785581734030475264 |