Feedback between deformation and magmatism in the Lloyds River Fault Zone : an example of episodic fault reactivation in an accretionary setting, Newfoundland Appalachians
Author Posting. © American Geophysical Union, 2006. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Tectonics 25 (2006): TC4004, doi:10.1029/2005TC001789. The Lloyds River Fault Zone is a 10–15...
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ftwhoas:oai:darchive.mblwhoilibrary.org:1912/3469 2023-05-15T17:22:53+02:00 Feedback between deformation and magmatism in the Lloyds River Fault Zone : an example of episodic fault reactivation in an accretionary setting, Newfoundland Appalachians Lissenberg, C. Johan van Staal, Cees R. 2006-07-08 application/pdf https://hdl.handle.net/1912/3469 en_US eng American Geophysical Union https://doi.org/10.1029/2005TC001789 Tectonics 25 (2006): TC4004 https://hdl.handle.net/1912/3469 doi:10.1029/2005TC001789 Tectonics 25 (2006): TC4004 doi:10.1029/2005TC001789 Shear zones Magmatism Appalachians Article 2006 ftwhoas https://doi.org/10.1029/2005TC001789 2022-05-28T22:57:58Z Author Posting. © American Geophysical Union, 2006. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Tectonics 25 (2006): TC4004, doi:10.1029/2005TC001789. The Lloyds River Fault Zone is a 10–15 km wide amphibolite-grade shear zone that formed during the Ordovician Taconic Orogeny. It separates ophiolites and arc–back-arc complexes formed in Iapetus from a peri-Laurentian microcontinent (Dashwoods microcontinent). The Lloyds River Fault Zone comprises three high-strain zones, dominantly composed of mylonitic amphibolites, separated by less deformed plutonic rocks. Structural, age and metamorphic data suggest the Lloyds River Fault Zone accommodated sinistral-oblique underthrusting of ophiolites underneath the Dashwoods microcontinent prior to 471 ± 5 Ma at 800°C and 6 kbar. Plutonic rocks within the Lloyds River Fault Zone comprise two suites dated at 464 ± 2 plus 462 ± 2 and 459 ± 3 Ma, respectively. The younger age of the plutons with respect to some of the amphibolites, evidence for magmatic deformation, and the elongate nature of the plutons parallel to the Lloyds River Fault Zone suggest they were emplaced within the fault zone during deformation. Both intrusive episodes triggered renewed deformation at high temperatures (770–750°C), illustrating the positive feedback between deformation and magmatism. Offshoots of the plutons intruded undeformed ophiolitic gabbros outside the Lloyds River Fault Zone. Deformation localized within the intrusive sheets, coeval with static contact metamorphism of the host gabbros, leading to the development of new, small-scale shear zones. This illustrates that channeling of plutons into shear zones and nucleation of shear zones in melt-rich zones may occur simultaneously within the same fault system. This research is funded by a scholarship from the Faculty of Graduate and Postdoctoral Studies, University of Ottawa, to C.J.L. and a NSERC grant to C.v.S in his position ... Article in Journal/Newspaper Newfoundland Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Tectonics 25 4 n/a n/a |
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Open Polar |
collection |
Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) |
op_collection_id |
ftwhoas |
language |
English |
topic |
Shear zones Magmatism Appalachians |
spellingShingle |
Shear zones Magmatism Appalachians Lissenberg, C. Johan van Staal, Cees R. Feedback between deformation and magmatism in the Lloyds River Fault Zone : an example of episodic fault reactivation in an accretionary setting, Newfoundland Appalachians |
topic_facet |
Shear zones Magmatism Appalachians |
description |
Author Posting. © American Geophysical Union, 2006. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Tectonics 25 (2006): TC4004, doi:10.1029/2005TC001789. The Lloyds River Fault Zone is a 10–15 km wide amphibolite-grade shear zone that formed during the Ordovician Taconic Orogeny. It separates ophiolites and arc–back-arc complexes formed in Iapetus from a peri-Laurentian microcontinent (Dashwoods microcontinent). The Lloyds River Fault Zone comprises three high-strain zones, dominantly composed of mylonitic amphibolites, separated by less deformed plutonic rocks. Structural, age and metamorphic data suggest the Lloyds River Fault Zone accommodated sinistral-oblique underthrusting of ophiolites underneath the Dashwoods microcontinent prior to 471 ± 5 Ma at 800°C and 6 kbar. Plutonic rocks within the Lloyds River Fault Zone comprise two suites dated at 464 ± 2 plus 462 ± 2 and 459 ± 3 Ma, respectively. The younger age of the plutons with respect to some of the amphibolites, evidence for magmatic deformation, and the elongate nature of the plutons parallel to the Lloyds River Fault Zone suggest they were emplaced within the fault zone during deformation. Both intrusive episodes triggered renewed deformation at high temperatures (770–750°C), illustrating the positive feedback between deformation and magmatism. Offshoots of the plutons intruded undeformed ophiolitic gabbros outside the Lloyds River Fault Zone. Deformation localized within the intrusive sheets, coeval with static contact metamorphism of the host gabbros, leading to the development of new, small-scale shear zones. This illustrates that channeling of plutons into shear zones and nucleation of shear zones in melt-rich zones may occur simultaneously within the same fault system. This research is funded by a scholarship from the Faculty of Graduate and Postdoctoral Studies, University of Ottawa, to C.J.L. and a NSERC grant to C.v.S in his position ... |
format |
Article in Journal/Newspaper |
author |
Lissenberg, C. Johan van Staal, Cees R. |
author_facet |
Lissenberg, C. Johan van Staal, Cees R. |
author_sort |
Lissenberg, C. Johan |
title |
Feedback between deformation and magmatism in the Lloyds River Fault Zone : an example of episodic fault reactivation in an accretionary setting, Newfoundland Appalachians |
title_short |
Feedback between deformation and magmatism in the Lloyds River Fault Zone : an example of episodic fault reactivation in an accretionary setting, Newfoundland Appalachians |
title_full |
Feedback between deformation and magmatism in the Lloyds River Fault Zone : an example of episodic fault reactivation in an accretionary setting, Newfoundland Appalachians |
title_fullStr |
Feedback between deformation and magmatism in the Lloyds River Fault Zone : an example of episodic fault reactivation in an accretionary setting, Newfoundland Appalachians |
title_full_unstemmed |
Feedback between deformation and magmatism in the Lloyds River Fault Zone : an example of episodic fault reactivation in an accretionary setting, Newfoundland Appalachians |
title_sort |
feedback between deformation and magmatism in the lloyds river fault zone : an example of episodic fault reactivation in an accretionary setting, newfoundland appalachians |
publisher |
American Geophysical Union |
publishDate |
2006 |
url |
https://hdl.handle.net/1912/3469 |
genre |
Newfoundland |
genre_facet |
Newfoundland |
op_source |
Tectonics 25 (2006): TC4004 doi:10.1029/2005TC001789 |
op_relation |
https://doi.org/10.1029/2005TC001789 Tectonics 25 (2006): TC4004 https://hdl.handle.net/1912/3469 doi:10.1029/2005TC001789 |
op_doi |
https://doi.org/10.1029/2005TC001789 |
container_title |
Tectonics |
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25 |
container_issue |
4 |
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1766109787918958592 |