Lithospheric architecture beneath Hudson Bay
Hudson Bay overlies some of the thickest Precambrian lithosphere on Earth, whose internal structures contain important clues to the earliest workings of plate formation. The terminal collision, the Trans-Hudson Orogen, brought together the Western Churchill craton to the northwest and the Superior c...
Published in: | Geochemistry, Geophysics, Geosystems |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
American Geophysical Union
|
Subjects: | |
Online Access: | http://hdl.handle.net/1885/153131 https://doi.org/10.1002/2015GC005845 |
id |
ftanucanberra:oai:openresearch-repository.anu.edu.au:1885/153131 |
---|---|
record_format |
openpolar |
spelling |
ftanucanberra:oai:openresearch-repository.anu.edu.au:1885/153131 2024-01-14T10:07:30+01:00 Lithospheric architecture beneath Hudson Bay Porritt, Robert W. Miller, Meghan Darbyshire, Fiona A. application/pdf http://hdl.handle.net/1885/153131 https://doi.org/10.1002/2015GC005845 unknown American Geophysical Union 1525-2027 http://hdl.handle.net/1885/153131 doi:10.1002/2015GC005845 Geochemistry, Geophysics, Geosystems Journal article ftanucanberra https://doi.org/10.1002/2015GC005845 2023-12-15T09:39:26Z Hudson Bay overlies some of the thickest Precambrian lithosphere on Earth, whose internal structures contain important clues to the earliest workings of plate formation. The terminal collision, the Trans-Hudson Orogen, brought together the Western Churchill craton to the northwest and the Superior craton to the southeast. These two Archean cratons along with the Paleo-Proterozoic Trans-Hudson internides, form the core of the North American craton. We use S to P converted wave imaging and absolute shear velocity information from a joint inversion of P to S receiver functions, new ambient noise derived phase velocities, and teleseismic phase velocities to investigate this region and determine both the thickness of the lithosphere and the presence of internal discontinuities. The lithosphere under central Hudson Bay approaches ∼350 km thick but is thinner (∼200-250 km) around the periphery of the Bay. Furthermore, the amplitude of the LAB conversion from the S receiver functions is unusually large for a craton, suggesting a large thermal contrast across the LAB, which we interpret as direct evidence of the thermal insulation effect of continents on the asthenosphere. Within the lithosphere, midlithospheric discontinuities, significantly shallower than the base of the lithosphere, are often imaged, suggesting the mechanisms that form these layers are common. Lacking time-history information, we infer that these discontinuities reflect reactivation of formation structures during deformation of the craton. Key Points: The thick lithosphere of Hudson Bay has significant structural variation We directly image the thermal blanketing on the asthenosphere The lithospheric thickness of Hudson Bay is 200-350 km Article in Journal/Newspaper Hudson Bay Australian National University: ANU Digital Collections Hudson Bay Hudson Geochemistry, Geophysics, Geosystems 16 7 2262 2275 |
institution |
Open Polar |
collection |
Australian National University: ANU Digital Collections |
op_collection_id |
ftanucanberra |
language |
unknown |
description |
Hudson Bay overlies some of the thickest Precambrian lithosphere on Earth, whose internal structures contain important clues to the earliest workings of plate formation. The terminal collision, the Trans-Hudson Orogen, brought together the Western Churchill craton to the northwest and the Superior craton to the southeast. These two Archean cratons along with the Paleo-Proterozoic Trans-Hudson internides, form the core of the North American craton. We use S to P converted wave imaging and absolute shear velocity information from a joint inversion of P to S receiver functions, new ambient noise derived phase velocities, and teleseismic phase velocities to investigate this region and determine both the thickness of the lithosphere and the presence of internal discontinuities. The lithosphere under central Hudson Bay approaches ∼350 km thick but is thinner (∼200-250 km) around the periphery of the Bay. Furthermore, the amplitude of the LAB conversion from the S receiver functions is unusually large for a craton, suggesting a large thermal contrast across the LAB, which we interpret as direct evidence of the thermal insulation effect of continents on the asthenosphere. Within the lithosphere, midlithospheric discontinuities, significantly shallower than the base of the lithosphere, are often imaged, suggesting the mechanisms that form these layers are common. Lacking time-history information, we infer that these discontinuities reflect reactivation of formation structures during deformation of the craton. Key Points: The thick lithosphere of Hudson Bay has significant structural variation We directly image the thermal blanketing on the asthenosphere The lithospheric thickness of Hudson Bay is 200-350 km |
format |
Article in Journal/Newspaper |
author |
Porritt, Robert W. Miller, Meghan Darbyshire, Fiona A. |
spellingShingle |
Porritt, Robert W. Miller, Meghan Darbyshire, Fiona A. Lithospheric architecture beneath Hudson Bay |
author_facet |
Porritt, Robert W. Miller, Meghan Darbyshire, Fiona A. |
author_sort |
Porritt, Robert W. |
title |
Lithospheric architecture beneath Hudson Bay |
title_short |
Lithospheric architecture beneath Hudson Bay |
title_full |
Lithospheric architecture beneath Hudson Bay |
title_fullStr |
Lithospheric architecture beneath Hudson Bay |
title_full_unstemmed |
Lithospheric architecture beneath Hudson Bay |
title_sort |
lithospheric architecture beneath hudson bay |
publisher |
American Geophysical Union |
url |
http://hdl.handle.net/1885/153131 https://doi.org/10.1002/2015GC005845 |
geographic |
Hudson Bay Hudson |
geographic_facet |
Hudson Bay Hudson |
genre |
Hudson Bay |
genre_facet |
Hudson Bay |
op_source |
Geochemistry, Geophysics, Geosystems |
op_relation |
1525-2027 http://hdl.handle.net/1885/153131 doi:10.1002/2015GC005845 |
op_doi |
https://doi.org/10.1002/2015GC005845 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
16 |
container_issue |
7 |
container_start_page |
2262 |
op_container_end_page |
2275 |
_version_ |
1788061905695277056 |