Constraints on the composition of the crust and uppermost mantle in northwestern Canada: Vp/ Vs variations along Lithoprobe's SNorCLE transect
Shear-wave seismic data recorded along four profiles during the SNoRE 97 (1997 Slave Northern Cordillera Refraction Experiment) refraction wide-angle reflection experiment in northwestern Canada are analyzed to provide S-wave velocity (Vs) models. These are combined with previous P-wave velocity...
Published in: | Canadian Journal of Earth Sciences |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Canadian Science Publishing
2005
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1139/e05-028 http://www.nrcresearchpress.com/doi/pdf/10.1139/e05-028 |
id |
crcansciencepubl:10.1139/e05-028 |
---|---|
record_format |
openpolar |
spelling |
crcansciencepubl:10.1139/e05-028 2024-06-23T07:52:53+00:00 Constraints on the composition of the crust and uppermost mantle in northwestern Canada: Vp/ Vs variations along Lithoprobe's SNorCLE transect Fernández-Viejo, Gabriela Clowes, Ron M Welford, J Kim 2005 http://dx.doi.org/10.1139/e05-028 http://www.nrcresearchpress.com/doi/pdf/10.1139/e05-028 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 42, issue 6, page 1205-1222 ISSN 0008-4077 1480-3313 journal-article 2005 crcansciencepubl https://doi.org/10.1139/e05-028 2024-06-13T04:10:51Z Shear-wave seismic data recorded along four profiles during the SNoRE 97 (1997 Slave Northern Cordillera Refraction Experiment) refraction wide-angle reflection experiment in northwestern Canada are analyzed to provide S-wave velocity (Vs) models. These are combined with previous P-wave velocity (Vp) models to produce cross sections of the ratio Vp/Vs for the crust and upper mantle. The Vp/Vs values are related to rock types through comparisons with published laboratory data. The Slave craton has low Vp/Vs values of 1.681.72, indicating a predominantly silicic crustal composition. Higher values (1.78) for the Great Bear and eastern Hottah domains of the Wopmay orogen imply a more mafic than average crustal composition. In the western Hottah and Fort Simpson arc, values of Vp/Vs drop to ∼1.69. These low values continue westward for 700 km into the Foreland and Omineca belts of the Cordillera, providing support for the interpretation from coincident seismic reflection studies that much of the crust from east of the Cordilleran deformation front to the Stikinia terrane of the Intermontane Belt consists of quartzose metasedimentary rocks. Stikinia shows values of 1.781.73, consistent with its derivation as a volcanic arc terrane. Upper mantle velocity and ratio values beneath the Slave craton indicate an ultramafic peridotitic composition. In the Wopmay orogen, the presence of low Vp/Vs ratios beneath the Hottah Fort Simpson transition indicates the presence of pyroxenite in the upper mantle. Across the northern Cordillera, low Vp values and a moderate-to-high ratio in the uppermost mantle are consistent with the region's high heat flow and the possible presence of partial melt. Article in Journal/Newspaper Fort Simpson Canadian Science Publishing Canada Fort Simpson ENVELOPE(-121.320,-121.320,61.808,61.808) Canadian Journal of Earth Sciences 42 6 1205 1222 |
institution |
Open Polar |
collection |
Canadian Science Publishing |
op_collection_id |
crcansciencepubl |
language |
English |
description |
Shear-wave seismic data recorded along four profiles during the SNoRE 97 (1997 Slave Northern Cordillera Refraction Experiment) refraction wide-angle reflection experiment in northwestern Canada are analyzed to provide S-wave velocity (Vs) models. These are combined with previous P-wave velocity (Vp) models to produce cross sections of the ratio Vp/Vs for the crust and upper mantle. The Vp/Vs values are related to rock types through comparisons with published laboratory data. The Slave craton has low Vp/Vs values of 1.681.72, indicating a predominantly silicic crustal composition. Higher values (1.78) for the Great Bear and eastern Hottah domains of the Wopmay orogen imply a more mafic than average crustal composition. In the western Hottah and Fort Simpson arc, values of Vp/Vs drop to ∼1.69. These low values continue westward for 700 km into the Foreland and Omineca belts of the Cordillera, providing support for the interpretation from coincident seismic reflection studies that much of the crust from east of the Cordilleran deformation front to the Stikinia terrane of the Intermontane Belt consists of quartzose metasedimentary rocks. Stikinia shows values of 1.781.73, consistent with its derivation as a volcanic arc terrane. Upper mantle velocity and ratio values beneath the Slave craton indicate an ultramafic peridotitic composition. In the Wopmay orogen, the presence of low Vp/Vs ratios beneath the Hottah Fort Simpson transition indicates the presence of pyroxenite in the upper mantle. Across the northern Cordillera, low Vp values and a moderate-to-high ratio in the uppermost mantle are consistent with the region's high heat flow and the possible presence of partial melt. |
format |
Article in Journal/Newspaper |
author |
Fernández-Viejo, Gabriela Clowes, Ron M Welford, J Kim |
spellingShingle |
Fernández-Viejo, Gabriela Clowes, Ron M Welford, J Kim Constraints on the composition of the crust and uppermost mantle in northwestern Canada: Vp/ Vs variations along Lithoprobe's SNorCLE transect |
author_facet |
Fernández-Viejo, Gabriela Clowes, Ron M Welford, J Kim |
author_sort |
Fernández-Viejo, Gabriela |
title |
Constraints on the composition of the crust and uppermost mantle in northwestern Canada: Vp/ Vs variations along Lithoprobe's SNorCLE transect |
title_short |
Constraints on the composition of the crust and uppermost mantle in northwestern Canada: Vp/ Vs variations along Lithoprobe's SNorCLE transect |
title_full |
Constraints on the composition of the crust and uppermost mantle in northwestern Canada: Vp/ Vs variations along Lithoprobe's SNorCLE transect |
title_fullStr |
Constraints on the composition of the crust and uppermost mantle in northwestern Canada: Vp/ Vs variations along Lithoprobe's SNorCLE transect |
title_full_unstemmed |
Constraints on the composition of the crust and uppermost mantle in northwestern Canada: Vp/ Vs variations along Lithoprobe's SNorCLE transect |
title_sort |
constraints on the composition of the crust and uppermost mantle in northwestern canada: vp/ vs variations along lithoprobe's snorcle transect |
publisher |
Canadian Science Publishing |
publishDate |
2005 |
url |
http://dx.doi.org/10.1139/e05-028 http://www.nrcresearchpress.com/doi/pdf/10.1139/e05-028 |
long_lat |
ENVELOPE(-121.320,-121.320,61.808,61.808) |
geographic |
Canada Fort Simpson |
geographic_facet |
Canada Fort Simpson |
genre |
Fort Simpson |
genre_facet |
Fort Simpson |
op_source |
Canadian Journal of Earth Sciences volume 42, issue 6, page 1205-1222 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e05-028 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
42 |
container_issue |
6 |
container_start_page |
1205 |
op_container_end_page |
1222 |
_version_ |
1802644315454832640 |