Early Proterozoic magmatism in Yukon, Canada: constraints on the evolution of northwestern Laurentia
Northwestern Laurentia, after cratonization at about 1.85 Ga, underwent a series of tectonic and magmatic events during the Proterozoic that were followed by separation of Laurentia from another landmass, probably Australia. The oldest magmatic event produced the Bonnet Plume River Intrusions (BPRI)...
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National Research Council, Canada
2001
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ftunivtasecite:oai:ecite.utas.edu.au:23264 2023-05-15T13:59:07+02:00 Early Proterozoic magmatism in Yukon, Canada: constraints on the evolution of northwestern Laurentia Thorkelson, D Mortenson, JK Creaser, RA Davidson, GJ Abbott, JG 2001 https://doi.org/10.1139/cjes-38-10-1479 http://ecite.utas.edu.au/23264 en eng National Research Council, Canada http://dx.doi.org/10.1139/cjes-38-10-1479 Thorkelson, D and Mortenson, JK and Creaser, RA and Davidson, GJ and Abbott, JG, Early Proterozoic magmatism in Yukon, Canada: constraints on the evolution of northwestern Laurentia, Canadian Journal of Earth Sciences, 38, (10) pp. 1479-1494. ISSN 0008-4077 (2001) [Refereed Article] http://ecite.utas.edu.au/23264 Earth Sciences Geology Igneous and Metamorphic Petrology Refereed Article PeerReviewed 2001 ftunivtasecite https://doi.org/10.1139/cjes-38-10-1479 2019-12-13T21:05:01Z Northwestern Laurentia, after cratonization at about 1.85 Ga, underwent a series of tectonic and magmatic events during the Proterozoic that were followed by separation of Laurentia from another landmass, probably Australia. The oldest magmatic event produced the Bonnet Plume River Intrusions (BPRI), which intruded the Wernecke Supergroup as short dikes and small stocks. The BPRI are hydrothermally altered tholeiitic diorites, gabbros, and subordinate anorthositic and syenitic rocks, with trace element signatures consistent with a rift origin. Depleted mantle model ages range from 2.29 to 2.57 Ga and Nd values range from +0.7 to -1.7. An increasing crustal component is apparent in rocks with more evolved compositions. Four U-Pb zircon ages (1705.9 0.7, 1709.4 1.4, 1711.1 5.1, and 1713.6 12.7 Ma) indicate a Paleoproterozoic age for the BPRI. These dates constrain the age of the Wernecke Supergroup to ca. 1710 Ma, making it the oldest supracrustal succession in western Laurentia, e.g., >240 Ma older than the Belt Supergroup of southeastern British Columbia and the northwestern United States. The Wernecke Supergroup was deposited in the first rift basin to open along the western margin of Laurentia, but was later inverted by the pre-1.6 Ga Racklan Orogeny, an event possibly influenced by transmission of compression from the Yavapai and Mazatzal orogenies in southern Laurentia. The Neoproterozoic southwestern United States - east Antarctica (SWEAT) reconstruction, which places Australia next to northwestern Laurentia, is supported by linkages between Paleoproterozoic and Mesoproterozoic geological features in northwestern Canada and Australia. Article in Journal/Newspaper Antarc* Antarctica East Antarctica Yukon eCite UTAS (University of Tasmania) Bonnet Plume River ENVELOPE(-134.938,-134.938,65.933,65.933) British Columbia ENVELOPE(-125.003,-125.003,54.000,54.000) Canada East Antarctica Wernecke ENVELOPE(-135.271,-135.271,63.952,63.952) Yukon Canadian Journal of Earth Sciences 38 10 1479 1494 |
institution |
Open Polar |
collection |
eCite UTAS (University of Tasmania) |
op_collection_id |
ftunivtasecite |
language |
English |
topic |
Earth Sciences Geology Igneous and Metamorphic Petrology |
spellingShingle |
Earth Sciences Geology Igneous and Metamorphic Petrology Thorkelson, D Mortenson, JK Creaser, RA Davidson, GJ Abbott, JG Early Proterozoic magmatism in Yukon, Canada: constraints on the evolution of northwestern Laurentia |
topic_facet |
Earth Sciences Geology Igneous and Metamorphic Petrology |
description |
Northwestern Laurentia, after cratonization at about 1.85 Ga, underwent a series of tectonic and magmatic events during the Proterozoic that were followed by separation of Laurentia from another landmass, probably Australia. The oldest magmatic event produced the Bonnet Plume River Intrusions (BPRI), which intruded the Wernecke Supergroup as short dikes and small stocks. The BPRI are hydrothermally altered tholeiitic diorites, gabbros, and subordinate anorthositic and syenitic rocks, with trace element signatures consistent with a rift origin. Depleted mantle model ages range from 2.29 to 2.57 Ga and Nd values range from +0.7 to -1.7. An increasing crustal component is apparent in rocks with more evolved compositions. Four U-Pb zircon ages (1705.9 0.7, 1709.4 1.4, 1711.1 5.1, and 1713.6 12.7 Ma) indicate a Paleoproterozoic age for the BPRI. These dates constrain the age of the Wernecke Supergroup to ca. 1710 Ma, making it the oldest supracrustal succession in western Laurentia, e.g., >240 Ma older than the Belt Supergroup of southeastern British Columbia and the northwestern United States. The Wernecke Supergroup was deposited in the first rift basin to open along the western margin of Laurentia, but was later inverted by the pre-1.6 Ga Racklan Orogeny, an event possibly influenced by transmission of compression from the Yavapai and Mazatzal orogenies in southern Laurentia. The Neoproterozoic southwestern United States - east Antarctica (SWEAT) reconstruction, which places Australia next to northwestern Laurentia, is supported by linkages between Paleoproterozoic and Mesoproterozoic geological features in northwestern Canada and Australia. |
format |
Article in Journal/Newspaper |
author |
Thorkelson, D Mortenson, JK Creaser, RA Davidson, GJ Abbott, JG |
author_facet |
Thorkelson, D Mortenson, JK Creaser, RA Davidson, GJ Abbott, JG |
author_sort |
Thorkelson, D |
title |
Early Proterozoic magmatism in Yukon, Canada: constraints on the evolution of northwestern Laurentia |
title_short |
Early Proterozoic magmatism in Yukon, Canada: constraints on the evolution of northwestern Laurentia |
title_full |
Early Proterozoic magmatism in Yukon, Canada: constraints on the evolution of northwestern Laurentia |
title_fullStr |
Early Proterozoic magmatism in Yukon, Canada: constraints on the evolution of northwestern Laurentia |
title_full_unstemmed |
Early Proterozoic magmatism in Yukon, Canada: constraints on the evolution of northwestern Laurentia |
title_sort |
early proterozoic magmatism in yukon, canada: constraints on the evolution of northwestern laurentia |
publisher |
National Research Council, Canada |
publishDate |
2001 |
url |
https://doi.org/10.1139/cjes-38-10-1479 http://ecite.utas.edu.au/23264 |
long_lat |
ENVELOPE(-134.938,-134.938,65.933,65.933) ENVELOPE(-125.003,-125.003,54.000,54.000) ENVELOPE(-135.271,-135.271,63.952,63.952) |
geographic |
Bonnet Plume River British Columbia Canada East Antarctica Wernecke Yukon |
geographic_facet |
Bonnet Plume River British Columbia Canada East Antarctica Wernecke Yukon |
genre |
Antarc* Antarctica East Antarctica Yukon |
genre_facet |
Antarc* Antarctica East Antarctica Yukon |
op_relation |
http://dx.doi.org/10.1139/cjes-38-10-1479 Thorkelson, D and Mortenson, JK and Creaser, RA and Davidson, GJ and Abbott, JG, Early Proterozoic magmatism in Yukon, Canada: constraints on the evolution of northwestern Laurentia, Canadian Journal of Earth Sciences, 38, (10) pp. 1479-1494. ISSN 0008-4077 (2001) [Refereed Article] http://ecite.utas.edu.au/23264 |
op_doi |
https://doi.org/10.1139/cjes-38-10-1479 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
38 |
container_issue |
10 |
container_start_page |
1479 |
op_container_end_page |
1494 |
_version_ |
1766267516108144640 |