New reflections on the structure and evolution of the Makkovikian - Ketilidian Orogen in Labrador and southern Greenland
Marine seismic reflection profiles across the Early Proterozoic Makkovikian - Ketilidian Orogen in the Labrador Sea region suggest that it is a doubly vergent, asymmetric orogenic belt, comparable in width to younger collisional orogens. A southeast dipping reflector package is correlated with on-la...
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Format: | Article in Journal/Newspaper |
Language: | English |
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American Geophysical Union
1997
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Online Access: | https://research.library.mun.ca/1736/ https://research.library.mun.ca/1736/1/New_reflections_on_the_structure_and_evolution_of_the_Makkovikian_-_Ketilidian_Orogen_in_Labrador_and_southern_Greenland.pdf https://research.library.mun.ca/1736/3/New_reflections_on_the_structure_and_evolution_of_the_Makkovikian_-_Ketilidian_Orogen_in_Labrador_and_southern_Greenland.pdf https://doi.org/10.1029/97TC02286 |
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ftmemorialuniv:oai:research.library.mun.ca:1736 2023-10-01T03:56:20+02:00 New reflections on the structure and evolution of the Makkovikian - Ketilidian Orogen in Labrador and southern Greenland Kerr, Andrew Hall, Jeremy Wardle, Richard J. Gower, Charles F. Ryan, Bruce 1997-12 application/pdf https://research.library.mun.ca/1736/ https://research.library.mun.ca/1736/1/New_reflections_on_the_structure_and_evolution_of_the_Makkovikian_-_Ketilidian_Orogen_in_Labrador_and_southern_Greenland.pdf https://research.library.mun.ca/1736/3/New_reflections_on_the_structure_and_evolution_of_the_Makkovikian_-_Ketilidian_Orogen_in_Labrador_and_southern_Greenland.pdf https://doi.org/10.1029/97TC02286 en eng American Geophysical Union https://research.library.mun.ca/1736/1/New_reflections_on_the_structure_and_evolution_of_the_Makkovikian_-_Ketilidian_Orogen_in_Labrador_and_southern_Greenland.pdf https://research.library.mun.ca/1736/3/New_reflections_on_the_structure_and_evolution_of_the_Makkovikian_-_Ketilidian_Orogen_in_Labrador_and_southern_Greenland.pdf Kerr, Andrew <https://research.library.mun.ca/view/creator_az/Kerr=3AAndrew=3A=3A.html> and Hall, Jeremy <https://research.library.mun.ca/view/creator_az/Hall=3AJeremy=3A=3A.html> and Wardle, Richard J. <https://research.library.mun.ca/view/creator_az/Wardle=3ARichard_J=2E=3A=3A.html> and Gower, Charles F. <https://research.library.mun.ca/view/creator_az/Gower=3ACharles_F=2E=3A=3A.html> and Ryan, Bruce <https://research.library.mun.ca/view/creator_az/Ryan=3ABruce=3A=3A.html> (1997) New reflections on the structure and evolution of the Makkovikian - Ketilidian Orogen in Labrador and southern Greenland. Tectonics, 16 (6). pp. 942-965. ISSN 1944-9194 cc_by_nc Q Science (General) Article PeerReviewed 1997 ftmemorialuniv https://doi.org/10.1029/97TC02286 2023-09-03T06:44:31Z Marine seismic reflection profiles across the Early Proterozoic Makkovikian - Ketilidian Orogen in the Labrador Sea region suggest that it is a doubly vergent, asymmetric orogenic belt, comparable in width to younger collisional orogens. A southeast dipping reflector package is correlated with on-land shear zones that mark the southeastern limit of exposed reworked Archean crust and is also associated with a cryptic isotopic boundary in granites, which documents a transition from “ancient” to “juvenile” basement. This boundary is interpreted as a suture, along which juvenile Proterozoic crust has been juxtaposed over (thrust over ?) the Archean craton. A major synorogenic to postorogenic plutonic terrane to the southeast has a poorly reflective upper crust but shows strong subhorizontal reflectivity in the lower crust and Moho regions. The southeastern part of the profile correlates with metasedimentary terranes of the Ketilidian Belt in Greenland and contains low-angle, northwest dipping, reflector packages suggestive of large-scale crustal imbrication by thrusting. At least two broad zones of reflectivity at mantle depths (up to 16 s) are also recognized. One dips northwest below the Archean craton, but the most widespread mantle reflectivity is southeast dipping in opposition to the dominant fabric in the overlying crust. These contrasting crustal and subcrustal reflectivity patterns define a geometric “focus” beneath the orogenic belt and may provide information about subduction polarity during its development. The doubly vergent reflectivity pattern resembles images from possibly correlative Precambrian orogenic belts such as the Penokean and Svecofennian and also younger “small collisional orogens” such as the Appalachian and Pyrenean belts. It also broadly resembles some results of geodynamic crustal deformation models based on detachment and underthrusting of mantle lithosphere following collision and the squeezing of “weak” zones between rigid bounding blocks. A speculative multistage model for the belt ... Article in Journal/Newspaper Greenland Labrador Sea Memorial University of Newfoundland: Research Repository Greenland Tectonics 16 6 942 965 |
institution |
Open Polar |
collection |
Memorial University of Newfoundland: Research Repository |
op_collection_id |
ftmemorialuniv |
language |
English |
topic |
Q Science (General) |
spellingShingle |
Q Science (General) Kerr, Andrew Hall, Jeremy Wardle, Richard J. Gower, Charles F. Ryan, Bruce New reflections on the structure and evolution of the Makkovikian - Ketilidian Orogen in Labrador and southern Greenland |
topic_facet |
Q Science (General) |
description |
Marine seismic reflection profiles across the Early Proterozoic Makkovikian - Ketilidian Orogen in the Labrador Sea region suggest that it is a doubly vergent, asymmetric orogenic belt, comparable in width to younger collisional orogens. A southeast dipping reflector package is correlated with on-land shear zones that mark the southeastern limit of exposed reworked Archean crust and is also associated with a cryptic isotopic boundary in granites, which documents a transition from “ancient” to “juvenile” basement. This boundary is interpreted as a suture, along which juvenile Proterozoic crust has been juxtaposed over (thrust over ?) the Archean craton. A major synorogenic to postorogenic plutonic terrane to the southeast has a poorly reflective upper crust but shows strong subhorizontal reflectivity in the lower crust and Moho regions. The southeastern part of the profile correlates with metasedimentary terranes of the Ketilidian Belt in Greenland and contains low-angle, northwest dipping, reflector packages suggestive of large-scale crustal imbrication by thrusting. At least two broad zones of reflectivity at mantle depths (up to 16 s) are also recognized. One dips northwest below the Archean craton, but the most widespread mantle reflectivity is southeast dipping in opposition to the dominant fabric in the overlying crust. These contrasting crustal and subcrustal reflectivity patterns define a geometric “focus” beneath the orogenic belt and may provide information about subduction polarity during its development. The doubly vergent reflectivity pattern resembles images from possibly correlative Precambrian orogenic belts such as the Penokean and Svecofennian and also younger “small collisional orogens” such as the Appalachian and Pyrenean belts. It also broadly resembles some results of geodynamic crustal deformation models based on detachment and underthrusting of mantle lithosphere following collision and the squeezing of “weak” zones between rigid bounding blocks. A speculative multistage model for the belt ... |
format |
Article in Journal/Newspaper |
author |
Kerr, Andrew Hall, Jeremy Wardle, Richard J. Gower, Charles F. Ryan, Bruce |
author_facet |
Kerr, Andrew Hall, Jeremy Wardle, Richard J. Gower, Charles F. Ryan, Bruce |
author_sort |
Kerr, Andrew |
title |
New reflections on the structure and evolution of the Makkovikian - Ketilidian Orogen in Labrador and southern Greenland |
title_short |
New reflections on the structure and evolution of the Makkovikian - Ketilidian Orogen in Labrador and southern Greenland |
title_full |
New reflections on the structure and evolution of the Makkovikian - Ketilidian Orogen in Labrador and southern Greenland |
title_fullStr |
New reflections on the structure and evolution of the Makkovikian - Ketilidian Orogen in Labrador and southern Greenland |
title_full_unstemmed |
New reflections on the structure and evolution of the Makkovikian - Ketilidian Orogen in Labrador and southern Greenland |
title_sort |
new reflections on the structure and evolution of the makkovikian - ketilidian orogen in labrador and southern greenland |
publisher |
American Geophysical Union |
publishDate |
1997 |
url |
https://research.library.mun.ca/1736/ https://research.library.mun.ca/1736/1/New_reflections_on_the_structure_and_evolution_of_the_Makkovikian_-_Ketilidian_Orogen_in_Labrador_and_southern_Greenland.pdf https://research.library.mun.ca/1736/3/New_reflections_on_the_structure_and_evolution_of_the_Makkovikian_-_Ketilidian_Orogen_in_Labrador_and_southern_Greenland.pdf https://doi.org/10.1029/97TC02286 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Labrador Sea |
genre_facet |
Greenland Labrador Sea |
op_relation |
https://research.library.mun.ca/1736/1/New_reflections_on_the_structure_and_evolution_of_the_Makkovikian_-_Ketilidian_Orogen_in_Labrador_and_southern_Greenland.pdf https://research.library.mun.ca/1736/3/New_reflections_on_the_structure_and_evolution_of_the_Makkovikian_-_Ketilidian_Orogen_in_Labrador_and_southern_Greenland.pdf Kerr, Andrew <https://research.library.mun.ca/view/creator_az/Kerr=3AAndrew=3A=3A.html> and Hall, Jeremy <https://research.library.mun.ca/view/creator_az/Hall=3AJeremy=3A=3A.html> and Wardle, Richard J. <https://research.library.mun.ca/view/creator_az/Wardle=3ARichard_J=2E=3A=3A.html> and Gower, Charles F. <https://research.library.mun.ca/view/creator_az/Gower=3ACharles_F=2E=3A=3A.html> and Ryan, Bruce <https://research.library.mun.ca/view/creator_az/Ryan=3ABruce=3A=3A.html> (1997) New reflections on the structure and evolution of the Makkovikian - Ketilidian Orogen in Labrador and southern Greenland. Tectonics, 16 (6). pp. 942-965. ISSN 1944-9194 |
op_rights |
cc_by_nc |
op_doi |
https://doi.org/10.1029/97TC02286 |
container_title |
Tectonics |
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16 |
container_issue |
6 |
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942 |
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965 |
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