Wide-angle seismic transect across the Torngat Orogen, northern Labrador: Evidence for a Proterozoic crustal root
A refraction/wide-angle reflection seismic transect across the Labrador peninsula covers the Core Zone of the SE Churchill Province, the Paleoproterozoic Torngat Orogen, and the Archean Nain Province including a portion of the Labrador continental margin. An airgun array was used as source, and 11 o...
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Online Access: | https://doi.org/10.1029/1999JB900010 http://hdl.handle.net/10222/26944 |
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ftdalhouse:oai:DalSpace.library.dal.ca:10222/26944 2023-05-15T17:13:58+02:00 Wide-angle seismic transect across the Torngat Orogen, northern Labrador: Evidence for a Proterozoic crustal root Funck, T. Louden, KE 2013-06-19T18:01:13Z https://doi.org/10.1029/1999JB900010 http://hdl.handle.net/10222/26944 unknown Journal of Geophysical Research-Solid Earth Funck, T., and KE Louden. 1999. "Wide-angle seismic transect across the Torngat Orogen, northern Labrador: Evidence for a Proterozoic crustal root." Journal of Geophysical Research-Solid Earth 104(B4): 7463-7480. DOI:10.1029/1999JB900010 0148-0227 http://dx.doi.org/10.1029/1999JB900010 http://hdl.handle.net/10222/26944 104 4 7463 This paper was published by AGU. Copyright 1999 American Geophysical Union article 2013 ftdalhouse https://doi.org/10.1029/1999JB900010 2021-12-29T18:08:42Z A refraction/wide-angle reflection seismic transect across the Labrador peninsula covers the Core Zone of the SE Churchill Province, the Paleoproterozoic Torngat Orogen, and the Archean Nain Province including a portion of the Labrador continental margin. An airgun array was used as source, and 11 ocean-bottom seismometers and 16 land stations recorded the shots. Forward modeling of travel times and amplitudes reveals a deep asymmetric crustal root beneath the Torngat Orogen, with a crustal thickness of >49 km and with P-wave velocities of 6.9-7.0 km/s. The geometry of the velocity model and the root can be best explained by either westward dipping subduction or westward underthrusting of the Nain crust. Gravity modeling suggests a correlation of the crustal root with a gravity low that extends similar to 100 km in an E-W direction and similar to 200 km from north to south. The preservation of the crustal root is attributed to the lack of postorogenic heating and ductile reworking consistent with the lack of abundant postcollisional magmatism in the SE Churchill Province. A discontinuity possibly cutting through the entire crust is interpreted as a zone of major transcurrent shearing associated with the main phase of deformation. West of the Torngat Orogen, the crustal thickness in the Core Zone of the Churchill Province varies between 35 and 38 km (P-wave velocities of 5.8-7.0 km/s). East of the orogen, the crystalline crust in the Nain Province is similar to 38 km thick (velocities from 5.8 to 6.9 km/s) but thins to 9 km in the shelf area of the Labrador margin, where it is covered with up to 8 km of sediments. No high-velocity zone was found beneath the thinned continental crust at the margin. Article in Journal/Newspaper Nain Dalhousie University: DalSpace Institutional Repository Nain ENVELOPE(-61.695,-61.695,56.542,56.542) Journal of Geophysical Research: Solid Earth 104 B4 7463 7480 |
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Open Polar |
collection |
Dalhousie University: DalSpace Institutional Repository |
op_collection_id |
ftdalhouse |
language |
unknown |
description |
A refraction/wide-angle reflection seismic transect across the Labrador peninsula covers the Core Zone of the SE Churchill Province, the Paleoproterozoic Torngat Orogen, and the Archean Nain Province including a portion of the Labrador continental margin. An airgun array was used as source, and 11 ocean-bottom seismometers and 16 land stations recorded the shots. Forward modeling of travel times and amplitudes reveals a deep asymmetric crustal root beneath the Torngat Orogen, with a crustal thickness of >49 km and with P-wave velocities of 6.9-7.0 km/s. The geometry of the velocity model and the root can be best explained by either westward dipping subduction or westward underthrusting of the Nain crust. Gravity modeling suggests a correlation of the crustal root with a gravity low that extends similar to 100 km in an E-W direction and similar to 200 km from north to south. The preservation of the crustal root is attributed to the lack of postorogenic heating and ductile reworking consistent with the lack of abundant postcollisional magmatism in the SE Churchill Province. A discontinuity possibly cutting through the entire crust is interpreted as a zone of major transcurrent shearing associated with the main phase of deformation. West of the Torngat Orogen, the crustal thickness in the Core Zone of the Churchill Province varies between 35 and 38 km (P-wave velocities of 5.8-7.0 km/s). East of the orogen, the crystalline crust in the Nain Province is similar to 38 km thick (velocities from 5.8 to 6.9 km/s) but thins to 9 km in the shelf area of the Labrador margin, where it is covered with up to 8 km of sediments. No high-velocity zone was found beneath the thinned continental crust at the margin. |
format |
Article in Journal/Newspaper |
author |
Funck, T. Louden, KE |
spellingShingle |
Funck, T. Louden, KE Wide-angle seismic transect across the Torngat Orogen, northern Labrador: Evidence for a Proterozoic crustal root |
author_facet |
Funck, T. Louden, KE |
author_sort |
Funck, T. |
title |
Wide-angle seismic transect across the Torngat Orogen, northern Labrador: Evidence for a Proterozoic crustal root |
title_short |
Wide-angle seismic transect across the Torngat Orogen, northern Labrador: Evidence for a Proterozoic crustal root |
title_full |
Wide-angle seismic transect across the Torngat Orogen, northern Labrador: Evidence for a Proterozoic crustal root |
title_fullStr |
Wide-angle seismic transect across the Torngat Orogen, northern Labrador: Evidence for a Proterozoic crustal root |
title_full_unstemmed |
Wide-angle seismic transect across the Torngat Orogen, northern Labrador: Evidence for a Proterozoic crustal root |
title_sort |
wide-angle seismic transect across the torngat orogen, northern labrador: evidence for a proterozoic crustal root |
publishDate |
2013 |
url |
https://doi.org/10.1029/1999JB900010 http://hdl.handle.net/10222/26944 |
long_lat |
ENVELOPE(-61.695,-61.695,56.542,56.542) |
geographic |
Nain |
geographic_facet |
Nain |
genre |
Nain |
genre_facet |
Nain |
op_relation |
Journal of Geophysical Research-Solid Earth Funck, T., and KE Louden. 1999. "Wide-angle seismic transect across the Torngat Orogen, northern Labrador: Evidence for a Proterozoic crustal root." Journal of Geophysical Research-Solid Earth 104(B4): 7463-7480. DOI:10.1029/1999JB900010 0148-0227 http://dx.doi.org/10.1029/1999JB900010 http://hdl.handle.net/10222/26944 104 4 7463 |
op_rights |
This paper was published by AGU. Copyright 1999 American Geophysical Union |
op_doi |
https://doi.org/10.1029/1999JB900010 |
container_title |
Journal of Geophysical Research: Solid Earth |
container_volume |
104 |
container_issue |
B4 |
container_start_page |
7463 |
op_container_end_page |
7480 |
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1766071213105348608 |