The Northern Termination of the Cache Creek Terrane in Yukon: Middle Triassic Arc Activity and Jurassic–Cretaceous Structural Imbrication
The northernmost part of the Cache Creek terrane lies in south-central Yukon and comprises metavolcanic rocks, hemipelagic chert and shale, newly identified volcaniclastic and clastic rocks (Michie formation, informal), pyroxenite and gabbro intrusive rocks with an arc to back-arc geochemical signat...
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ftboisestateu:oai:scholarworks.boisestate.edu:geo_facpubs-1508 2023-11-12T04:27:56+01:00 The Northern Termination of the Cache Creek Terrane in Yukon: Middle Triassic Arc Activity and Jurassic–Cretaceous Structural Imbrication Bickerton, Luke Colpron, Maurice Gibson, H. Daniel Thorkelson, Derek Crowley, James L. 2020-02-01T08:00:00Z https://scholarworks.boisestate.edu/geo_facpubs/504 https://doi.org/10.1139/cjes-2018-0262 unknown ScholarWorks https://scholarworks.boisestate.edu/geo_facpubs/504 https://doi.org/10.1139/cjes-2018-0262 Geosciences Faculty Publications and Presentations Cache Creek Kutcho Cordillera terrane accretion intra-oceanic arc Earth Sciences Geology Geophysics and Seismology text 2020 ftboisestateu https://doi.org/10.1139/cjes-2018-0262 2023-10-20T00:12:49Z The northernmost part of the Cache Creek terrane lies in south-central Yukon and comprises metavolcanic rocks, hemipelagic chert and shale, newly identified volcaniclastic and clastic rocks (Michie formation, informal), pyroxenite and gabbro intrusive rocks with an arc to back-arc geochemical signature, as well as tectonized and serpentinized ultramafic rocks. The proximally sourced Michie formation yielded zircon from two samples with unimodal peaks at 245.85 ± 0.07 and 244.64 ± 0.08 Ma. These dates are likely close to the depositional ages and compare favourably with those from the Kutcho assemblage of northern British Columbia. The Michie formation is exposed along the northwestern flank of Mount Michie and represents singular detrital input from a nearby eroding island-arc. The Cache Creek terrane rocks are imbricated with epiclastic and carbonate rocks of the Stikinia and Lower Jurassic siliciclastic rocks of the synorogenic Whitehorse trough. This imbrication records two compressional deformation phases in the region: (1) an initial phase of west-verging thrusting along the Judas Mountain fault that placed the Cache Creek terrane rocks over the arc and basinal rocks of Stikinia and Whitehorse trough; and (2) a second phase of east-verging thrusting along the Mount Michie fault that repositioned rocks of Stikinia and the Whitehorse trough structurally above those of the Cache Creek terrane. Deformation in the centre of the study area was followed by emplacement of a coarse-grained syenite that yielded 40Ar/39Ar biotite and muscovite cooling ages of 165–160 Ma. Text Whitehorse Yukon Boise State University: Scholar Works Judas ENVELOPE(-61.116,-61.116,-63.866,-63.866) Judas Mountain ENVELOPE(-134.183,-134.183,60.368,60.368) Mount Michie ENVELOPE(-134.099,-134.099,60.505,60.505) Yukon Canadian Journal of Earth Sciences 57 2 227 248 |
institution |
Open Polar |
collection |
Boise State University: Scholar Works |
op_collection_id |
ftboisestateu |
language |
unknown |
topic |
Cache Creek Kutcho Cordillera terrane accretion intra-oceanic arc Earth Sciences Geology Geophysics and Seismology |
spellingShingle |
Cache Creek Kutcho Cordillera terrane accretion intra-oceanic arc Earth Sciences Geology Geophysics and Seismology Bickerton, Luke Colpron, Maurice Gibson, H. Daniel Thorkelson, Derek Crowley, James L. The Northern Termination of the Cache Creek Terrane in Yukon: Middle Triassic Arc Activity and Jurassic–Cretaceous Structural Imbrication |
topic_facet |
Cache Creek Kutcho Cordillera terrane accretion intra-oceanic arc Earth Sciences Geology Geophysics and Seismology |
description |
The northernmost part of the Cache Creek terrane lies in south-central Yukon and comprises metavolcanic rocks, hemipelagic chert and shale, newly identified volcaniclastic and clastic rocks (Michie formation, informal), pyroxenite and gabbro intrusive rocks with an arc to back-arc geochemical signature, as well as tectonized and serpentinized ultramafic rocks. The proximally sourced Michie formation yielded zircon from two samples with unimodal peaks at 245.85 ± 0.07 and 244.64 ± 0.08 Ma. These dates are likely close to the depositional ages and compare favourably with those from the Kutcho assemblage of northern British Columbia. The Michie formation is exposed along the northwestern flank of Mount Michie and represents singular detrital input from a nearby eroding island-arc. The Cache Creek terrane rocks are imbricated with epiclastic and carbonate rocks of the Stikinia and Lower Jurassic siliciclastic rocks of the synorogenic Whitehorse trough. This imbrication records two compressional deformation phases in the region: (1) an initial phase of west-verging thrusting along the Judas Mountain fault that placed the Cache Creek terrane rocks over the arc and basinal rocks of Stikinia and Whitehorse trough; and (2) a second phase of east-verging thrusting along the Mount Michie fault that repositioned rocks of Stikinia and the Whitehorse trough structurally above those of the Cache Creek terrane. Deformation in the centre of the study area was followed by emplacement of a coarse-grained syenite that yielded 40Ar/39Ar biotite and muscovite cooling ages of 165–160 Ma. |
format |
Text |
author |
Bickerton, Luke Colpron, Maurice Gibson, H. Daniel Thorkelson, Derek Crowley, James L. |
author_facet |
Bickerton, Luke Colpron, Maurice Gibson, H. Daniel Thorkelson, Derek Crowley, James L. |
author_sort |
Bickerton, Luke |
title |
The Northern Termination of the Cache Creek Terrane in Yukon: Middle Triassic Arc Activity and Jurassic–Cretaceous Structural Imbrication |
title_short |
The Northern Termination of the Cache Creek Terrane in Yukon: Middle Triassic Arc Activity and Jurassic–Cretaceous Structural Imbrication |
title_full |
The Northern Termination of the Cache Creek Terrane in Yukon: Middle Triassic Arc Activity and Jurassic–Cretaceous Structural Imbrication |
title_fullStr |
The Northern Termination of the Cache Creek Terrane in Yukon: Middle Triassic Arc Activity and Jurassic–Cretaceous Structural Imbrication |
title_full_unstemmed |
The Northern Termination of the Cache Creek Terrane in Yukon: Middle Triassic Arc Activity and Jurassic–Cretaceous Structural Imbrication |
title_sort |
northern termination of the cache creek terrane in yukon: middle triassic arc activity and jurassic–cretaceous structural imbrication |
publisher |
ScholarWorks |
publishDate |
2020 |
url |
https://scholarworks.boisestate.edu/geo_facpubs/504 https://doi.org/10.1139/cjes-2018-0262 |
long_lat |
ENVELOPE(-61.116,-61.116,-63.866,-63.866) ENVELOPE(-134.183,-134.183,60.368,60.368) ENVELOPE(-134.099,-134.099,60.505,60.505) |
geographic |
Judas Judas Mountain Mount Michie Yukon |
geographic_facet |
Judas Judas Mountain Mount Michie Yukon |
genre |
Whitehorse Yukon |
genre_facet |
Whitehorse Yukon |
op_source |
Geosciences Faculty Publications and Presentations |
op_relation |
https://scholarworks.boisestate.edu/geo_facpubs/504 https://doi.org/10.1139/cjes-2018-0262 |
op_doi |
https://doi.org/10.1139/cjes-2018-0262 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
57 |
container_issue |
2 |
container_start_page |
227 |
op_container_end_page |
248 |
_version_ |
1782341356110217216 |