Cross-strike potential-field anomalies in the Canadian Cordillera
Application of bandpass and directional filtering to potential-field maps of western Canada has led to the discovery of regionally extensive anomalies crossing the northwest strike of Cordilleran structures. The most prominent of these, the SteamboatFraser trend, is a northsouth-striking feature t...
Published in: | Canadian Journal of Earth Sciences |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Canadian Science Publishing
2003
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1139/e02-100 http://www.nrcresearchpress.com/doi/pdf/10.1139/e02-100 |
id |
crcansciencepubl:10.1139/e02-100 |
---|---|
record_format |
openpolar |
spelling |
crcansciencepubl:10.1139/e02-100 2023-12-17T10:33:15+01:00 Cross-strike potential-field anomalies in the Canadian Cordillera Cook, Frederick A Lynn, C Elissa Hall, Kevin W 2003 http://dx.doi.org/10.1139/e02-100 http://www.nrcresearchpress.com/doi/pdf/10.1139/e02-100 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 40, issue 1, page 1-11 ISSN 0008-4077 1480-3313 General Earth and Planetary Sciences journal-article 2003 crcansciencepubl https://doi.org/10.1139/e02-100 2023-11-19T13:39:20Z Application of bandpass and directional filtering to potential-field maps of western Canada has led to the discovery of regionally extensive anomalies crossing the northwest strike of Cordilleran structures. The most prominent of these, the SteamboatFraser trend, is a northsouth-striking feature that projects from the foreland belt in northeastern British Columbia, where it becomes subparallel to anomalies east of the Mackenzie Mountains, southward to the northern limit of the Fraser River strike-slip fault, a distance of about 600 km. Within the hinterland of the Cordillera, the trend appears to spatially correlate with the margins of some Tertiary volcanics. The northeasternmost, and thus most cratonward, Tertiary volcanics are located on the northern projection of the trend. The trend may thus be interpreted as either late, post-orogenic intrusives (e.g., dikes and related volcanic rocks) that are only partially exposed, as pre-orogenic (pre-Mesozoic) features (e.g., faults, dikes) in the crust that were overridden by the Cordilleran thrust sheets, or a combination of these. Although it is not possible to determine which of these (pre- or post-orogenic) is appropriate for the trend, the eventual choice has important implications for the structure and evolution of this part of the Cordillera. If the source of the anomalies is pre-orogenic, a major implication is that Precambrian Shield rocks would be present at depth beneath the southern Canadian Cordillera as far west as the Fraser River fault. Alternatively, if the source is post-orogenic, it represents an anomalously linear feature that has no obvious expression on the surface other than a poorly defined spatial correlation with the margins of some Tertiary volcanics. Article in Journal/Newspaper Mackenzie mountains Canadian Science Publishing (via Crossref) Canada British Columbia ENVELOPE(-125.003,-125.003,54.000,54.000) Steamboat ENVELOPE(-123.720,-123.720,58.683,58.683) Fraser River ENVELOPE(-62.243,-62.243,56.619,56.619) Canadian Journal of Earth Sciences 40 1 1 11 |
institution |
Open Polar |
collection |
Canadian Science Publishing (via Crossref) |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
General Earth and Planetary Sciences |
spellingShingle |
General Earth and Planetary Sciences Cook, Frederick A Lynn, C Elissa Hall, Kevin W Cross-strike potential-field anomalies in the Canadian Cordillera |
topic_facet |
General Earth and Planetary Sciences |
description |
Application of bandpass and directional filtering to potential-field maps of western Canada has led to the discovery of regionally extensive anomalies crossing the northwest strike of Cordilleran structures. The most prominent of these, the SteamboatFraser trend, is a northsouth-striking feature that projects from the foreland belt in northeastern British Columbia, where it becomes subparallel to anomalies east of the Mackenzie Mountains, southward to the northern limit of the Fraser River strike-slip fault, a distance of about 600 km. Within the hinterland of the Cordillera, the trend appears to spatially correlate with the margins of some Tertiary volcanics. The northeasternmost, and thus most cratonward, Tertiary volcanics are located on the northern projection of the trend. The trend may thus be interpreted as either late, post-orogenic intrusives (e.g., dikes and related volcanic rocks) that are only partially exposed, as pre-orogenic (pre-Mesozoic) features (e.g., faults, dikes) in the crust that were overridden by the Cordilleran thrust sheets, or a combination of these. Although it is not possible to determine which of these (pre- or post-orogenic) is appropriate for the trend, the eventual choice has important implications for the structure and evolution of this part of the Cordillera. If the source of the anomalies is pre-orogenic, a major implication is that Precambrian Shield rocks would be present at depth beneath the southern Canadian Cordillera as far west as the Fraser River fault. Alternatively, if the source is post-orogenic, it represents an anomalously linear feature that has no obvious expression on the surface other than a poorly defined spatial correlation with the margins of some Tertiary volcanics. |
format |
Article in Journal/Newspaper |
author |
Cook, Frederick A Lynn, C Elissa Hall, Kevin W |
author_facet |
Cook, Frederick A Lynn, C Elissa Hall, Kevin W |
author_sort |
Cook, Frederick A |
title |
Cross-strike potential-field anomalies in the Canadian Cordillera |
title_short |
Cross-strike potential-field anomalies in the Canadian Cordillera |
title_full |
Cross-strike potential-field anomalies in the Canadian Cordillera |
title_fullStr |
Cross-strike potential-field anomalies in the Canadian Cordillera |
title_full_unstemmed |
Cross-strike potential-field anomalies in the Canadian Cordillera |
title_sort |
cross-strike potential-field anomalies in the canadian cordillera |
publisher |
Canadian Science Publishing |
publishDate |
2003 |
url |
http://dx.doi.org/10.1139/e02-100 http://www.nrcresearchpress.com/doi/pdf/10.1139/e02-100 |
long_lat |
ENVELOPE(-125.003,-125.003,54.000,54.000) ENVELOPE(-123.720,-123.720,58.683,58.683) ENVELOPE(-62.243,-62.243,56.619,56.619) |
geographic |
Canada British Columbia Steamboat Fraser River |
geographic_facet |
Canada British Columbia Steamboat Fraser River |
genre |
Mackenzie mountains |
genre_facet |
Mackenzie mountains |
op_source |
Canadian Journal of Earth Sciences volume 40, issue 1, page 1-11 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e02-100 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
40 |
container_issue |
1 |
container_start_page |
1 |
op_container_end_page |
11 |
_version_ |
1785587188158693376 |