Early Proterozoic magmatism in Yukon, Canada: constraints on the evolution of northwestern
Abstract: 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 Intrusi...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.487.984 2023-05-15T13:54:06+02:00 Early Proterozoic magmatism in Yukon, Canada: constraints on the evolution of northwestern Derek J. Thorkelson James K. Mortensen Robert A. Creaser Garry J. Davidson J. Grant Abbott The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.487.984 http://eprints.utas.edu.au/761/1/cjes_Thorkelson_etal.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.487.984 http://eprints.utas.edu.au/761/1/cjes_Thorkelson_etal.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://eprints.utas.edu.au/761/1/cjes_Thorkelson_etal.pdf text ftciteseerx 2016-01-08T08:18:17Z Abstract: 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 sub-ordinate 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 e 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. Text Antarc* Antarctica East Antarctica Yukon Unknown 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 |
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English |
description |
Abstract: 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 sub-ordinate 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 e 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. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Derek J. Thorkelson James K. Mortensen Robert A. Creaser Garry J. Davidson J. Grant Abbott |
spellingShingle |
Derek J. Thorkelson James K. Mortensen Robert A. Creaser Garry J. Davidson J. Grant Abbott Early Proterozoic magmatism in Yukon, Canada: constraints on the evolution of northwestern |
author_facet |
Derek J. Thorkelson James K. Mortensen Robert A. Creaser Garry J. Davidson J. Grant Abbott |
author_sort |
Derek J. Thorkelson |
title |
Early Proterozoic magmatism in Yukon, Canada: constraints on the evolution of northwestern |
title_short |
Early Proterozoic magmatism in Yukon, Canada: constraints on the evolution of northwestern |
title_full |
Early Proterozoic magmatism in Yukon, Canada: constraints on the evolution of northwestern |
title_fullStr |
Early Proterozoic magmatism in Yukon, Canada: constraints on the evolution of northwestern |
title_full_unstemmed |
Early Proterozoic magmatism in Yukon, Canada: constraints on the evolution of northwestern |
title_sort |
early proterozoic magmatism in yukon, canada: constraints on the evolution of northwestern |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.487.984 http://eprints.utas.edu.au/761/1/cjes_Thorkelson_etal.pdf |
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_source |
http://eprints.utas.edu.au/761/1/cjes_Thorkelson_etal.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.487.984 http://eprints.utas.edu.au/761/1/cjes_Thorkelson_etal.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766259758730313728 |