Paleomagnetic and geobarometric study of the Late Cretaceous Mount Lorne stock, southern Yukon Territory
The ~75 Ma Mount Lorne monzodiorite stock has been studied paleomagnetically to estimate the tectonic motion of the northern Canadian Cordillera since the Late Cretaceous. The stock is one of several paleomagnetic studies currently underway at the University of Windsor Paleomagnetic Laboratory which...
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crcansciencepubl:10.1139/e99-026 2023-12-17T10:28:46+01:00 Paleomagnetic and geobarometric study of the Late Cretaceous Mount Lorne stock, southern Yukon Territory Harris, M J Symons, DTA Blackburn, W H Hart, CJR 1999 http://dx.doi.org/10.1139/e99-026 http://www.nrcresearchpress.com/doi/pdf/10.1139/e99-026 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 36, issue 6, page 905-915 ISSN 0008-4077 1480-3313 General Earth and Planetary Sciences journal-article 1999 crcansciencepubl https://doi.org/10.1139/e99-026 2023-11-19T13:38:33Z The ~75 Ma Mount Lorne monzodiorite stock has been studied paleomagnetically to estimate the tectonic motion of the northern Canadian Cordillera since the Late Cretaceous. The stock is one of several paleomagnetic studies currently underway at the University of Windsor Paleomagnetic Laboratory which are funded by the Lithoprobe - Slave northern Cordillera Lithospheric Evolution (SNORCLE) Project. Al-in-hornblende geobarometry and plagioclase-amphibole geothermometry data suggest that the stock has not been tilted since emplacement but does provide evidence that the stock has a normal fault trending north-south through its centre with the east side uplifted relatively by ~1000 m. Paleomagnetic measurements from 12 of 19 granitoid sites yield a well-defined characteristic remanent magnetization direction that is south-southwest and up, and a further six sites yield a direction that is north-northeast and down. Data from a mafic dike yield a negative contact test, suggesting that the dike is coeval with the stock. Combining the 18 granitic site mean characteristic remanent magnetization directions yields a paleopole at 69.1°W, 78.3°N (d p = 4.1°, d m = 4.5°) which suggests that the host Stikine Terrane has been translated poleward by 10.5 ± 3.5° (1170 ± 390 km) and rotated clockwise by 57 ± 11° relative to the North American craton between 75 and 50 Ma. Except for the estimate from the nearby coeval Carmacks Group volcanic rocks, the Mount Lorne estimate is consistent with all other paleomagnetic results within the Stikine Terrane. These latter estimates are also consistent with plate-tectonic models that suggest the Pacific oceanic plates had an increased velocity northwards during the Late Cretaceous. Article in Journal/Newspaper Carmacks Yukon Canadian Science Publishing (via Crossref) Yukon Pacific Stikine ENVELOPE(-131.803,-131.803,56.699,56.699) Carmacks ENVELOPE(-136.293,-136.293,62.088,62.088) Mount Lorne ENVELOPE(-134.861,-134.861,60.448,60.448) Canadian Journal of Earth Sciences 36 6 905 915 |
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 Harris, M J Symons, DTA Blackburn, W H Hart, CJR Paleomagnetic and geobarometric study of the Late Cretaceous Mount Lorne stock, southern Yukon Territory |
topic_facet |
General Earth and Planetary Sciences |
description |
The ~75 Ma Mount Lorne monzodiorite stock has been studied paleomagnetically to estimate the tectonic motion of the northern Canadian Cordillera since the Late Cretaceous. The stock is one of several paleomagnetic studies currently underway at the University of Windsor Paleomagnetic Laboratory which are funded by the Lithoprobe - Slave northern Cordillera Lithospheric Evolution (SNORCLE) Project. Al-in-hornblende geobarometry and plagioclase-amphibole geothermometry data suggest that the stock has not been tilted since emplacement but does provide evidence that the stock has a normal fault trending north-south through its centre with the east side uplifted relatively by ~1000 m. Paleomagnetic measurements from 12 of 19 granitoid sites yield a well-defined characteristic remanent magnetization direction that is south-southwest and up, and a further six sites yield a direction that is north-northeast and down. Data from a mafic dike yield a negative contact test, suggesting that the dike is coeval with the stock. Combining the 18 granitic site mean characteristic remanent magnetization directions yields a paleopole at 69.1°W, 78.3°N (d p = 4.1°, d m = 4.5°) which suggests that the host Stikine Terrane has been translated poleward by 10.5 ± 3.5° (1170 ± 390 km) and rotated clockwise by 57 ± 11° relative to the North American craton between 75 and 50 Ma. Except for the estimate from the nearby coeval Carmacks Group volcanic rocks, the Mount Lorne estimate is consistent with all other paleomagnetic results within the Stikine Terrane. These latter estimates are also consistent with plate-tectonic models that suggest the Pacific oceanic plates had an increased velocity northwards during the Late Cretaceous. |
format |
Article in Journal/Newspaper |
author |
Harris, M J Symons, DTA Blackburn, W H Hart, CJR |
author_facet |
Harris, M J Symons, DTA Blackburn, W H Hart, CJR |
author_sort |
Harris, M J |
title |
Paleomagnetic and geobarometric study of the Late Cretaceous Mount Lorne stock, southern Yukon Territory |
title_short |
Paleomagnetic and geobarometric study of the Late Cretaceous Mount Lorne stock, southern Yukon Territory |
title_full |
Paleomagnetic and geobarometric study of the Late Cretaceous Mount Lorne stock, southern Yukon Territory |
title_fullStr |
Paleomagnetic and geobarometric study of the Late Cretaceous Mount Lorne stock, southern Yukon Territory |
title_full_unstemmed |
Paleomagnetic and geobarometric study of the Late Cretaceous Mount Lorne stock, southern Yukon Territory |
title_sort |
paleomagnetic and geobarometric study of the late cretaceous mount lorne stock, southern yukon territory |
publisher |
Canadian Science Publishing |
publishDate |
1999 |
url |
http://dx.doi.org/10.1139/e99-026 http://www.nrcresearchpress.com/doi/pdf/10.1139/e99-026 |
long_lat |
ENVELOPE(-131.803,-131.803,56.699,56.699) ENVELOPE(-136.293,-136.293,62.088,62.088) ENVELOPE(-134.861,-134.861,60.448,60.448) |
geographic |
Yukon Pacific Stikine Carmacks Mount Lorne |
geographic_facet |
Yukon Pacific Stikine Carmacks Mount Lorne |
genre |
Carmacks Yukon |
genre_facet |
Carmacks Yukon |
op_source |
Canadian Journal of Earth Sciences volume 36, issue 6, page 905-915 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e99-026 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
36 |
container_issue |
6 |
container_start_page |
905 |
op_container_end_page |
915 |
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1785580957181411328 |