Long-lived (180 Myr) ductile flow within the Great Slave Lake shear zone
The Great Slave Lake shear zone (GSLsz) is a type example for deeply eroded continental transform boundaries located in the Northwest Territories, Canada. Formed during the oblique convergence of the Archean Rae and Slave cratons, the GSLsz has accommodated up to 700 km of dextral shear. Here we pre...
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Online Access: | http://dx.doi.org/10.22541/essoar.167160828.85653467/v1 |
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crwinnower:10.22541/essoar.167160828.85653467/v1 2024-06-02T08:07:10+00:00 Long-lived (180 Myr) ductile flow within the Great Slave Lake shear zone Šilerová, Dana Dyck, Brendan Cutts, Jamie A Larson, Kyle 2022 http://dx.doi.org/10.22541/essoar.167160828.85653467/v1 unknown Authorea, Inc. posted-content 2022 crwinnower https://doi.org/10.22541/essoar.167160828.85653467/v1 2024-05-07T14:19:27Z The Great Slave Lake shear zone (GSLsz) is a type example for deeply eroded continental transform boundaries located in the Northwest Territories, Canada. Formed during the oblique convergence of the Archean Rae and Slave cratons, the GSLsz has accommodated up to 700 km of dextral shear. Here we present the results of in situ U-Pb apatite and titanite geochronology from 11 samples that were collected across the strike of the shear zone. Both geochronometers record a near-continuous history of ductile shear during crustal cooling and exhumation that spans ca. 1920–1740 Ma. By integrating the geochronological data with structural and metamorphic observations across the structure, we propose a tectonic model for the shear zone that consists of three stages. The first stage (ca. 1920–1880 Ma) is characterized by strain accommodation along two coeval fault strands. During the second stage (ca. 1880–1800 Ma), ductile shear ceases along the northernmost fault strand and the locus of strain migrates southwards towards the hinterland of the Rae cratonic margin. In the third stage (ca. 1800–1740 Ma), ductile strain localizes back along the southern of the two original fault strands, after which the present-day surface level of the shear zone transitions to brittle shear. Our results highlight both the significance of the lateral migration of the zone of active deformation in major crustal shear zones as well as the localization of strain along existing crustal structures. Other/Unknown Material Great Slave Lake Northwest Territories The Winnower Canada Great Slave Lake ENVELOPE(-114.001,-114.001,61.500,61.500) Northwest Territories Rae ENVELOPE(-116.053,-116.053,62.834,62.834) |
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description |
The Great Slave Lake shear zone (GSLsz) is a type example for deeply eroded continental transform boundaries located in the Northwest Territories, Canada. Formed during the oblique convergence of the Archean Rae and Slave cratons, the GSLsz has accommodated up to 700 km of dextral shear. Here we present the results of in situ U-Pb apatite and titanite geochronology from 11 samples that were collected across the strike of the shear zone. Both geochronometers record a near-continuous history of ductile shear during crustal cooling and exhumation that spans ca. 1920–1740 Ma. By integrating the geochronological data with structural and metamorphic observations across the structure, we propose a tectonic model for the shear zone that consists of three stages. The first stage (ca. 1920–1880 Ma) is characterized by strain accommodation along two coeval fault strands. During the second stage (ca. 1880–1800 Ma), ductile shear ceases along the northernmost fault strand and the locus of strain migrates southwards towards the hinterland of the Rae cratonic margin. In the third stage (ca. 1800–1740 Ma), ductile strain localizes back along the southern of the two original fault strands, after which the present-day surface level of the shear zone transitions to brittle shear. Our results highlight both the significance of the lateral migration of the zone of active deformation in major crustal shear zones as well as the localization of strain along existing crustal structures. |
format |
Other/Unknown Material |
author |
Šilerová, Dana Dyck, Brendan Cutts, Jamie A Larson, Kyle |
spellingShingle |
Šilerová, Dana Dyck, Brendan Cutts, Jamie A Larson, Kyle Long-lived (180 Myr) ductile flow within the Great Slave Lake shear zone |
author_facet |
Šilerová, Dana Dyck, Brendan Cutts, Jamie A Larson, Kyle |
author_sort |
Šilerová, Dana |
title |
Long-lived (180 Myr) ductile flow within the Great Slave Lake shear zone |
title_short |
Long-lived (180 Myr) ductile flow within the Great Slave Lake shear zone |
title_full |
Long-lived (180 Myr) ductile flow within the Great Slave Lake shear zone |
title_fullStr |
Long-lived (180 Myr) ductile flow within the Great Slave Lake shear zone |
title_full_unstemmed |
Long-lived (180 Myr) ductile flow within the Great Slave Lake shear zone |
title_sort |
long-lived (180 myr) ductile flow within the great slave lake shear zone |
publisher |
Authorea, Inc. |
publishDate |
2022 |
url |
http://dx.doi.org/10.22541/essoar.167160828.85653467/v1 |
long_lat |
ENVELOPE(-114.001,-114.001,61.500,61.500) ENVELOPE(-116.053,-116.053,62.834,62.834) |
geographic |
Canada Great Slave Lake Northwest Territories Rae |
geographic_facet |
Canada Great Slave Lake Northwest Territories Rae |
genre |
Great Slave Lake Northwest Territories |
genre_facet |
Great Slave Lake Northwest Territories |
op_doi |
https://doi.org/10.22541/essoar.167160828.85653467/v1 |
_version_ |
1800752176091365376 |