Rifting of Western Laurentia at 1.38 Ga: The Hart River Sills of Yukon, Canada
The Hart River sills are a set of mafic to intermediate intrusions that occur in northern Yukon, Canada. The largest sills are over 500 m thick and over 200 km long. New U-Pb dates of 1382.15 ± 0.39 Ma and 1382.14 ± 0.36 Ma were obtained via chemical abrasion thermal ionization mass spectrometry on...
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ftboisestateu:oai:scholarworks.boisestate.edu:geo_facpubs-1431 2023-11-12T04:03:07+01:00 Rifting of Western Laurentia at 1.38 Ga: The Hart River Sills of Yukon, Canada Verbaas, Jacob Thorkelson, Derek J. Milidragovic, Dejan Crowley, James L. Foster, David Gibson, H. Daniel Marshall, Daniel D. 2018-09-01T07:00:00Z https://scholarworks.boisestate.edu/geo_facpubs/427 https://doi.org/10.1016/j.lithos.2018.06.018 unknown ScholarWorks https://scholarworks.boisestate.edu/geo_facpubs/427 https://doi.org/10.1016/j.lithos.2018.06.018 Geosciences Faculty Publications and Presentations Earth Sciences Geophysics and Seismology text 2018 ftboisestateu https://doi.org/10.1016/j.lithos.2018.06.018 2023-10-20T00:12:57Z The Hart River sills are a set of mafic to intermediate intrusions that occur in northern Yukon, Canada. The largest sills are over 500 m thick and over 200 km long. New U-Pb dates of 1382.15 ± 0.39 Ma and 1382.14 ± 0.36 Ma were obtained via chemical abrasion thermal ionization mass spectrometry on zircon. Whole rock initial neodymium isotopic compositions of the Hart River sills are juvenile and have εNdi from +1.5 to +4.0. The primary mineralogy of the Hart River sills is predominated by clinopyroxene and plagioclase. Geochemical modeling indicates that the Hart River sills lie on a common liquid line of descent defined by a fractionating assemblage of plagioclase, clinopyroxene and minor olivine. The Hart River sills have rare earth element and high field strength abundances similar to normal mid-ocean ridge basalts (N-MORB) but are enriched in large ion lithophile elements. The Sm/Yb and Dy/Zr ratios indicate >8% partial melting of spinel-bearing mantle. During the emplacement of the Hart River sills, western Laurentia was juxtaposed with Australia and eastern Antarctica within the supercontinent Columbia. The degree of partial melting, similarity to N-MORB, and juvenile isotopic signature are consistent with an episode of rifting at 1.38 Ga. Coeval magmatism and intracontinental rift basins farther south on Laurentia provide additional evidence for rifting of supercontinent Columbia at 1.38 Ga. Text Antarc* Antarctica Yukon Boise State University: Scholar Works Canada Dy ENVELOPE(11.369,11.369,64.834,64.834) Hart River ENVELOPE(-136.382,-136.382,65.854,65.854) Yukon Lithos 316-317 243 260 |
institution |
Open Polar |
collection |
Boise State University: Scholar Works |
op_collection_id |
ftboisestateu |
language |
unknown |
topic |
Earth Sciences Geophysics and Seismology |
spellingShingle |
Earth Sciences Geophysics and Seismology Verbaas, Jacob Thorkelson, Derek J. Milidragovic, Dejan Crowley, James L. Foster, David Gibson, H. Daniel Marshall, Daniel D. Rifting of Western Laurentia at 1.38 Ga: The Hart River Sills of Yukon, Canada |
topic_facet |
Earth Sciences Geophysics and Seismology |
description |
The Hart River sills are a set of mafic to intermediate intrusions that occur in northern Yukon, Canada. The largest sills are over 500 m thick and over 200 km long. New U-Pb dates of 1382.15 ± 0.39 Ma and 1382.14 ± 0.36 Ma were obtained via chemical abrasion thermal ionization mass spectrometry on zircon. Whole rock initial neodymium isotopic compositions of the Hart River sills are juvenile and have εNdi from +1.5 to +4.0. The primary mineralogy of the Hart River sills is predominated by clinopyroxene and plagioclase. Geochemical modeling indicates that the Hart River sills lie on a common liquid line of descent defined by a fractionating assemblage of plagioclase, clinopyroxene and minor olivine. The Hart River sills have rare earth element and high field strength abundances similar to normal mid-ocean ridge basalts (N-MORB) but are enriched in large ion lithophile elements. The Sm/Yb and Dy/Zr ratios indicate >8% partial melting of spinel-bearing mantle. During the emplacement of the Hart River sills, western Laurentia was juxtaposed with Australia and eastern Antarctica within the supercontinent Columbia. The degree of partial melting, similarity to N-MORB, and juvenile isotopic signature are consistent with an episode of rifting at 1.38 Ga. Coeval magmatism and intracontinental rift basins farther south on Laurentia provide additional evidence for rifting of supercontinent Columbia at 1.38 Ga. |
format |
Text |
author |
Verbaas, Jacob Thorkelson, Derek J. Milidragovic, Dejan Crowley, James L. Foster, David Gibson, H. Daniel Marshall, Daniel D. |
author_facet |
Verbaas, Jacob Thorkelson, Derek J. Milidragovic, Dejan Crowley, James L. Foster, David Gibson, H. Daniel Marshall, Daniel D. |
author_sort |
Verbaas, Jacob |
title |
Rifting of Western Laurentia at 1.38 Ga: The Hart River Sills of Yukon, Canada |
title_short |
Rifting of Western Laurentia at 1.38 Ga: The Hart River Sills of Yukon, Canada |
title_full |
Rifting of Western Laurentia at 1.38 Ga: The Hart River Sills of Yukon, Canada |
title_fullStr |
Rifting of Western Laurentia at 1.38 Ga: The Hart River Sills of Yukon, Canada |
title_full_unstemmed |
Rifting of Western Laurentia at 1.38 Ga: The Hart River Sills of Yukon, Canada |
title_sort |
rifting of western laurentia at 1.38 ga: the hart river sills of yukon, canada |
publisher |
ScholarWorks |
publishDate |
2018 |
url |
https://scholarworks.boisestate.edu/geo_facpubs/427 https://doi.org/10.1016/j.lithos.2018.06.018 |
long_lat |
ENVELOPE(11.369,11.369,64.834,64.834) ENVELOPE(-136.382,-136.382,65.854,65.854) |
geographic |
Canada Dy Hart River Yukon |
geographic_facet |
Canada Dy Hart River Yukon |
genre |
Antarc* Antarctica Yukon |
genre_facet |
Antarc* Antarctica Yukon |
op_source |
Geosciences Faculty Publications and Presentations |
op_relation |
https://scholarworks.boisestate.edu/geo_facpubs/427 https://doi.org/10.1016/j.lithos.2018.06.018 |
op_doi |
https://doi.org/10.1016/j.lithos.2018.06.018 |
container_title |
Lithos |
container_volume |
316-317 |
container_start_page |
243 |
op_container_end_page |
260 |
_version_ |
1782336185619709952 |