High-resolution dating of granite petrogenesis and deformation in a lower crustal shear zone: Athabasca granulite terrane, Western Canadian Shield
The Athabasca granulite terrane represents > 20,000 km2 of continental lower crust exposed in the hanging wall of the ca. 1.85 Ga thrust-sense Legs Lake shear zone in the western Canadian Shield. The terrane and the thrust zone are cut by the Grease River shear zone. The structure hosts a syn-tec...
Main Authors: | , , , , |
---|---|
Format: | Text |
Language: | unknown |
Published: |
SelectedWorks
2008
|
Subjects: | |
Online Access: | https://works.bepress.com/michael_williams/84 http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V5Y-4SHVSYF-4&_user=1516330&_coverDate=09%2F15%2F2008&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_searchStrId=1528884806&_rerunOrigin=google&_acct=C000053443&_version |
id |
ftunivmassamh:oai:works.bepress.com:michael_williams-1083 |
---|---|
record_format |
openpolar |
spelling |
ftunivmassamh:oai:works.bepress.com:michael_williams-1083 2023-05-15T16:23:06+02:00 High-resolution dating of granite petrogenesis and deformation in a lower crustal shear zone: Athabasca granulite terrane, Western Canadian Shield Dumond, G McLean, N Williams, ML Jercinovic, MJ Bowring, SA 2008-01-01T08:00:00Z https://works.bepress.com/michael_williams/84 http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V5Y-4SHVSYF-4&_user=1516330&_coverDate=09%2F15%2F2008&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_searchStrId=1528884806&_rerunOrigin=google&_acct=C000053443&_version unknown SelectedWorks https://works.bepress.com/michael_williams/84 http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V5Y-4SHVSYF-4&_user=1516330&_coverDate=09%2F15%2F2008&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_searchStrId=1528884806&_rerunOrigin=google&_acct=C000053443&_version Michael Williams monazite zircon granite continental crust shear zone transpression 2008 Earth Sciences text 2008 ftunivmassamh 2022-01-09T20:38:00Z The Athabasca granulite terrane represents > 20,000 km2 of continental lower crust exposed in the hanging wall of the ca. 1.85 Ga thrust-sense Legs Lake shear zone in the western Canadian Shield. The terrane and the thrust zone are cut by the Grease River shear zone. The structure hosts a syn-tectonic granite dike with a high-precision ID-TIMS zircon 207Pb/206Pb crystallization age of 1922.6 ± 0.4 Ma (MSWD = 3.1, 2[sigma]). Detailed textural analysis and in situ electron probe microanalysis (EPMA) of monazite in the dike indicate three discrete episodes of strain accumulation, each corresponding to syn-kinematic growth of monazite. The results provide evidence for a previously unrecognized > 100 m.y. episodic record of sub-horizontal NW-SE shortening and dextral shear strain along the Grease River shear zone. High-Ca domains in ca. 1.92-1.90 Ga monazite are linked to protracted high-T strain (ca. 650-700 °C) at lower crustal depths (ca. 1.0 GPa) and correlated with indentation of the Slave craton along the Great Slave Lake shear zone. Syn-kinematic overgrowths of low-Ca monazite + apatite are interpreted as products of deformation-enhanced dissolution and re-precipitation of monazite at 1846 ± 9 Ma (MSWD = 1.1, 2[sigma]). The third generation of syn-kinematic monazite yield ca. 1.8 Ga ages. The dataset constrains, for the first time, coeval movement along the strike-slip Grease River shear zone and the thrust-sense Legs Lake shear zone during ca. 1.85 Ga dextral transpression and uplift of continental lower crust to middle crustal levels (ca. 0.5 GPa). Circa 1.8 Ga syn-kinematic monazite domains in dynamically recrystallized feldspars support brittle-ductile reactivation along the Grease River shear zone at shallower crustal levels, coincident with intra-continental strike-slip strain during culmination of the Trans-Hudson orogeny. Text Great Slave Lake University of Massachusetts: ScholarWorks@UMass Amherst Grease River ENVELOPE(-106.802,-106.802,59.368,59.368) Great Slave Lake ENVELOPE(-114.001,-114.001,61.500,61.500) Hudson Legs Lake ENVELOPE(-105.067,-105.067,59.417,59.417) |
institution |
Open Polar |
collection |
University of Massachusetts: ScholarWorks@UMass Amherst |
op_collection_id |
ftunivmassamh |
language |
unknown |
topic |
monazite zircon granite continental crust shear zone transpression 2008 Earth Sciences |
spellingShingle |
monazite zircon granite continental crust shear zone transpression 2008 Earth Sciences Dumond, G McLean, N Williams, ML Jercinovic, MJ Bowring, SA High-resolution dating of granite petrogenesis and deformation in a lower crustal shear zone: Athabasca granulite terrane, Western Canadian Shield |
topic_facet |
monazite zircon granite continental crust shear zone transpression 2008 Earth Sciences |
description |
The Athabasca granulite terrane represents > 20,000 km2 of continental lower crust exposed in the hanging wall of the ca. 1.85 Ga thrust-sense Legs Lake shear zone in the western Canadian Shield. The terrane and the thrust zone are cut by the Grease River shear zone. The structure hosts a syn-tectonic granite dike with a high-precision ID-TIMS zircon 207Pb/206Pb crystallization age of 1922.6 ± 0.4 Ma (MSWD = 3.1, 2[sigma]). Detailed textural analysis and in situ electron probe microanalysis (EPMA) of monazite in the dike indicate three discrete episodes of strain accumulation, each corresponding to syn-kinematic growth of monazite. The results provide evidence for a previously unrecognized > 100 m.y. episodic record of sub-horizontal NW-SE shortening and dextral shear strain along the Grease River shear zone. High-Ca domains in ca. 1.92-1.90 Ga monazite are linked to protracted high-T strain (ca. 650-700 °C) at lower crustal depths (ca. 1.0 GPa) and correlated with indentation of the Slave craton along the Great Slave Lake shear zone. Syn-kinematic overgrowths of low-Ca monazite + apatite are interpreted as products of deformation-enhanced dissolution and re-precipitation of monazite at 1846 ± 9 Ma (MSWD = 1.1, 2[sigma]). The third generation of syn-kinematic monazite yield ca. 1.8 Ga ages. The dataset constrains, for the first time, coeval movement along the strike-slip Grease River shear zone and the thrust-sense Legs Lake shear zone during ca. 1.85 Ga dextral transpression and uplift of continental lower crust to middle crustal levels (ca. 0.5 GPa). Circa 1.8 Ga syn-kinematic monazite domains in dynamically recrystallized feldspars support brittle-ductile reactivation along the Grease River shear zone at shallower crustal levels, coincident with intra-continental strike-slip strain during culmination of the Trans-Hudson orogeny. |
format |
Text |
author |
Dumond, G McLean, N Williams, ML Jercinovic, MJ Bowring, SA |
author_facet |
Dumond, G McLean, N Williams, ML Jercinovic, MJ Bowring, SA |
author_sort |
Dumond, G |
title |
High-resolution dating of granite petrogenesis and deformation in a lower crustal shear zone: Athabasca granulite terrane, Western Canadian Shield |
title_short |
High-resolution dating of granite petrogenesis and deformation in a lower crustal shear zone: Athabasca granulite terrane, Western Canadian Shield |
title_full |
High-resolution dating of granite petrogenesis and deformation in a lower crustal shear zone: Athabasca granulite terrane, Western Canadian Shield |
title_fullStr |
High-resolution dating of granite petrogenesis and deformation in a lower crustal shear zone: Athabasca granulite terrane, Western Canadian Shield |
title_full_unstemmed |
High-resolution dating of granite petrogenesis and deformation in a lower crustal shear zone: Athabasca granulite terrane, Western Canadian Shield |
title_sort |
high-resolution dating of granite petrogenesis and deformation in a lower crustal shear zone: athabasca granulite terrane, western canadian shield |
publisher |
SelectedWorks |
publishDate |
2008 |
url |
https://works.bepress.com/michael_williams/84 http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V5Y-4SHVSYF-4&_user=1516330&_coverDate=09%2F15%2F2008&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_searchStrId=1528884806&_rerunOrigin=google&_acct=C000053443&_version |
long_lat |
ENVELOPE(-106.802,-106.802,59.368,59.368) ENVELOPE(-114.001,-114.001,61.500,61.500) ENVELOPE(-105.067,-105.067,59.417,59.417) |
geographic |
Grease River Great Slave Lake Hudson Legs Lake |
geographic_facet |
Grease River Great Slave Lake Hudson Legs Lake |
genre |
Great Slave Lake |
genre_facet |
Great Slave Lake |
op_source |
Michael Williams |
op_relation |
https://works.bepress.com/michael_williams/84 http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V5Y-4SHVSYF-4&_user=1516330&_coverDate=09%2F15%2F2008&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_searchStrId=1528884806&_rerunOrigin=google&_acct=C000053443&_version |
_version_ |
1766011291034451968 |