Crustal section across the polar continent–ocean transition in Canada
The Canadian Arctic Transect extends northwards from the Canadian Shield across a thick (about 18 km) and wide (over 800 km) sedimentary section consisting of four overlapping basins. These overlie a continental crystalline crust that thins from 48 to 8 km towards the Canada Basin. The latter overli...
Published in: | Canadian Journal of Earth Sciences |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Canadian Science Publishing
1986
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1139/e86-063 http://www.nrcresearchpress.com/doi/pdf/10.1139/e86-063 |
id |
crcansciencepubl:10.1139/e86-063 |
---|---|
record_format |
openpolar |
spelling |
crcansciencepubl:10.1139/e86-063 2024-09-15T17:54:16+00:00 Crustal section across the polar continent–ocean transition in Canada Sobczak, L. W. Mayr, U. Sweeney, J. F. 1986 http://dx.doi.org/10.1139/e86-063 http://www.nrcresearchpress.com/doi/pdf/10.1139/e86-063 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 23, issue 5, page 608-621 ISSN 0008-4077 1480-3313 journal-article 1986 crcansciencepubl https://doi.org/10.1139/e86-063 2024-07-25T04:10:03Z The Canadian Arctic Transect extends northwards from the Canadian Shield across a thick (about 18 km) and wide (over 800 km) sedimentary section consisting of four overlapping basins. These overlie a continental crystalline crust that thins from 48 to 8 km towards the Canada Basin. The latter overlies a relatively thin (5 – 10 km thick) oceanic crust below the Arctic Ocean. The calculated gravity effects of the upper sedimentary section were stripped away from the observed gravity anomaly, and the residual anomalies were used to determine the boundaries between sediment and crystalline crust and between crust and mantle. Residual anomalies with short wavelength and steep gradients were used to modify the initial near-surface structural model and to identify zones of evaporite and mafic rocks within the sedimentary rock column.Some interesting results emerge from this analysis: (1) analysis of the gradients of the shelf and slope suggests that shelf subsidence is hinged about a line near the central axis of the Sverdrup Basin; (2) continental crystalline crust thins oceanward from 48 km to 8 km at the transition zone over a distance of 825 km and appears to have stretched from an original width of 543 km, for an apparent stretch factor of about 1.5; (3) sediment thickness is usually inversely related to the crystalline crustal thickness; (4) the mantle below the ocean appears to be less dense than below the continental crust, with an assumed significant vertical density boundary between the two below the continental shelf (transition zone); (5) this analysis supports the concept that evaporites occur along the axis of the Sverdrup Basin, and mafic rocks appear to be concentrated along the flanks of the Sverdrup Basin; and (6) seismicity usually occurs over areas of relatively positive gravity anomalies that are considered to be the result of uncompensated sedimentary loads or mafic igneous intrusions or are areas of uplifted and folded rocks. Article in Journal/Newspaper Arctic Ocean canada basin sverdrup basin Canadian Science Publishing Canadian Journal of Earth Sciences 23 5 608 621 |
institution |
Open Polar |
collection |
Canadian Science Publishing |
op_collection_id |
crcansciencepubl |
language |
English |
description |
The Canadian Arctic Transect extends northwards from the Canadian Shield across a thick (about 18 km) and wide (over 800 km) sedimentary section consisting of four overlapping basins. These overlie a continental crystalline crust that thins from 48 to 8 km towards the Canada Basin. The latter overlies a relatively thin (5 – 10 km thick) oceanic crust below the Arctic Ocean. The calculated gravity effects of the upper sedimentary section were stripped away from the observed gravity anomaly, and the residual anomalies were used to determine the boundaries between sediment and crystalline crust and between crust and mantle. Residual anomalies with short wavelength and steep gradients were used to modify the initial near-surface structural model and to identify zones of evaporite and mafic rocks within the sedimentary rock column.Some interesting results emerge from this analysis: (1) analysis of the gradients of the shelf and slope suggests that shelf subsidence is hinged about a line near the central axis of the Sverdrup Basin; (2) continental crystalline crust thins oceanward from 48 km to 8 km at the transition zone over a distance of 825 km and appears to have stretched from an original width of 543 km, for an apparent stretch factor of about 1.5; (3) sediment thickness is usually inversely related to the crystalline crustal thickness; (4) the mantle below the ocean appears to be less dense than below the continental crust, with an assumed significant vertical density boundary between the two below the continental shelf (transition zone); (5) this analysis supports the concept that evaporites occur along the axis of the Sverdrup Basin, and mafic rocks appear to be concentrated along the flanks of the Sverdrup Basin; and (6) seismicity usually occurs over areas of relatively positive gravity anomalies that are considered to be the result of uncompensated sedimentary loads or mafic igneous intrusions or are areas of uplifted and folded rocks. |
format |
Article in Journal/Newspaper |
author |
Sobczak, L. W. Mayr, U. Sweeney, J. F. |
spellingShingle |
Sobczak, L. W. Mayr, U. Sweeney, J. F. Crustal section across the polar continent–ocean transition in Canada |
author_facet |
Sobczak, L. W. Mayr, U. Sweeney, J. F. |
author_sort |
Sobczak, L. W. |
title |
Crustal section across the polar continent–ocean transition in Canada |
title_short |
Crustal section across the polar continent–ocean transition in Canada |
title_full |
Crustal section across the polar continent–ocean transition in Canada |
title_fullStr |
Crustal section across the polar continent–ocean transition in Canada |
title_full_unstemmed |
Crustal section across the polar continent–ocean transition in Canada |
title_sort |
crustal section across the polar continent–ocean transition in canada |
publisher |
Canadian Science Publishing |
publishDate |
1986 |
url |
http://dx.doi.org/10.1139/e86-063 http://www.nrcresearchpress.com/doi/pdf/10.1139/e86-063 |
genre |
Arctic Ocean canada basin sverdrup basin |
genre_facet |
Arctic Ocean canada basin sverdrup basin |
op_source |
Canadian Journal of Earth Sciences volume 23, issue 5, page 608-621 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e86-063 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
23 |
container_issue |
5 |
container_start_page |
608 |
op_container_end_page |
621 |
_version_ |
1810430521305464832 |