An overview of anorthosite-bearing layered intrusions in the Archaean craton of southern West Greenland and the Superior Province of Canada: implications for Archaean tectonics and the origin of megacrystic plagioclase
Anorthosite-bearing layered intrusions are unique to the Archaean rock record and are abundant in the Archaean craton of southern West Greenland and the Superior Province of Canada. These layered intrusions consist mainly of ultramafic rocks, gabbros, leucogabbros and anorthosites, and typically con...
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Taylor & Francis
2018
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Online Access: | https://dx.doi.org/10.6084/m9.figshare.5797827.v1 https://tandf.figshare.com/articles/An_overview_of_anorthosite-bearing_layered_intrusions_in_the_Archaean_craton_of_southern_West_Greenland_and_the_Superior_Province_of_Canada_implications_for_Archaean_tectonics_and_the_origin_of_megacrystic_plagioclase/5797827/1 |
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ftdatacite:10.6084/m9.figshare.5797827.v1 2023-05-15T16:28:22+02:00 An overview of anorthosite-bearing layered intrusions in the Archaean craton of southern West Greenland and the Superior Province of Canada: implications for Archaean tectonics and the origin of megacrystic plagioclase Polat, Ali Longstaffe, Fred J. Frei, Robert 2018 https://dx.doi.org/10.6084/m9.figshare.5797827.v1 https://tandf.figshare.com/articles/An_overview_of_anorthosite-bearing_layered_intrusions_in_the_Archaean_craton_of_southern_West_Greenland_and_the_Superior_Province_of_Canada_implications_for_Archaean_tectonics_and_the_origin_of_megacrystic_plagioclase/5797827/1 unknown Taylor & Francis https://dx.doi.org/10.1080/09853111.2018.1427408 https://dx.doi.org/10.6084/m9.figshare.5797827 Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode cc-by-4.0 CC-BY Neuroscience 59999 Environmental Sciences not elsewhere classified FOS Earth and related environmental sciences Ecology FOS Biological sciences 69999 Biological Sciences not elsewhere classified Other CreativeWork Online resource article 2018 ftdatacite https://doi.org/10.6084/m9.figshare.5797827.v1 https://doi.org/10.1080/09853111.2018.1427408 https://doi.org/10.6084/m9.figshare.5797827 2021-11-05T12:55:41Z Anorthosite-bearing layered intrusions are unique to the Archaean rock record and are abundant in the Archaean craton of southern West Greenland and the Superior Province of Canada. These layered intrusions consist mainly of ultramafic rocks, gabbros, leucogabbros and anorthosites, and typically contain high-Ca (>An 70 ) megacrystic (2–30 cm in diameter) plagioclase in anorthosite and leucogabbro units. They are spatially and temporally associated with basalt-dominated greenstone belts and are intruded by syn-to post-tectonic granitoid rocks. The layered intrusions, greenstone belts and granitoids all share the geochemical characteristics of Phanerozoic subduction zone magmas, suggesting that they formed mainly in a suprasubduction zone setting. Archaean anorthosite-bearing layered intrusions and spatially associated greenstone belts are interpreted to be fragments of oceanic crust, representing dismembered subduction-related ophiolites. We suggest that large degrees of partial melting (25–35%) in the hotter (1500–1600 °C) Archaean upper mantle beneath rifting arcs and backarc basins produced shallow, kilometre-scale hydrous magma chambers. Field observations suggest that megacrystic anorthosites were generated at the top of the magma chambers, or in sills, dykes and pods in the oceanic crust. The absence of high-Ca megacrystic anorthosites in post-Archaean layered intrusions and oceanic crust reflects the decline of mantle temperatures resulting from secular cooling of the Earth. Article in Journal/Newspaper Greenland DataCite Metadata Store (German National Library of Science and Technology) Canada Greenland |
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DataCite Metadata Store (German National Library of Science and Technology) |
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language |
unknown |
topic |
Neuroscience 59999 Environmental Sciences not elsewhere classified FOS Earth and related environmental sciences Ecology FOS Biological sciences 69999 Biological Sciences not elsewhere classified |
spellingShingle |
Neuroscience 59999 Environmental Sciences not elsewhere classified FOS Earth and related environmental sciences Ecology FOS Biological sciences 69999 Biological Sciences not elsewhere classified Polat, Ali Longstaffe, Fred J. Frei, Robert An overview of anorthosite-bearing layered intrusions in the Archaean craton of southern West Greenland and the Superior Province of Canada: implications for Archaean tectonics and the origin of megacrystic plagioclase |
topic_facet |
Neuroscience 59999 Environmental Sciences not elsewhere classified FOS Earth and related environmental sciences Ecology FOS Biological sciences 69999 Biological Sciences not elsewhere classified |
description |
Anorthosite-bearing layered intrusions are unique to the Archaean rock record and are abundant in the Archaean craton of southern West Greenland and the Superior Province of Canada. These layered intrusions consist mainly of ultramafic rocks, gabbros, leucogabbros and anorthosites, and typically contain high-Ca (>An 70 ) megacrystic (2–30 cm in diameter) plagioclase in anorthosite and leucogabbro units. They are spatially and temporally associated with basalt-dominated greenstone belts and are intruded by syn-to post-tectonic granitoid rocks. The layered intrusions, greenstone belts and granitoids all share the geochemical characteristics of Phanerozoic subduction zone magmas, suggesting that they formed mainly in a suprasubduction zone setting. Archaean anorthosite-bearing layered intrusions and spatially associated greenstone belts are interpreted to be fragments of oceanic crust, representing dismembered subduction-related ophiolites. We suggest that large degrees of partial melting (25–35%) in the hotter (1500–1600 °C) Archaean upper mantle beneath rifting arcs and backarc basins produced shallow, kilometre-scale hydrous magma chambers. Field observations suggest that megacrystic anorthosites were generated at the top of the magma chambers, or in sills, dykes and pods in the oceanic crust. The absence of high-Ca megacrystic anorthosites in post-Archaean layered intrusions and oceanic crust reflects the decline of mantle temperatures resulting from secular cooling of the Earth. |
format |
Article in Journal/Newspaper |
author |
Polat, Ali Longstaffe, Fred J. Frei, Robert |
author_facet |
Polat, Ali Longstaffe, Fred J. Frei, Robert |
author_sort |
Polat, Ali |
title |
An overview of anorthosite-bearing layered intrusions in the Archaean craton of southern West Greenland and the Superior Province of Canada: implications for Archaean tectonics and the origin of megacrystic plagioclase |
title_short |
An overview of anorthosite-bearing layered intrusions in the Archaean craton of southern West Greenland and the Superior Province of Canada: implications for Archaean tectonics and the origin of megacrystic plagioclase |
title_full |
An overview of anorthosite-bearing layered intrusions in the Archaean craton of southern West Greenland and the Superior Province of Canada: implications for Archaean tectonics and the origin of megacrystic plagioclase |
title_fullStr |
An overview of anorthosite-bearing layered intrusions in the Archaean craton of southern West Greenland and the Superior Province of Canada: implications for Archaean tectonics and the origin of megacrystic plagioclase |
title_full_unstemmed |
An overview of anorthosite-bearing layered intrusions in the Archaean craton of southern West Greenland and the Superior Province of Canada: implications for Archaean tectonics and the origin of megacrystic plagioclase |
title_sort |
overview of anorthosite-bearing layered intrusions in the archaean craton of southern west greenland and the superior province of canada: implications for archaean tectonics and the origin of megacrystic plagioclase |
publisher |
Taylor & Francis |
publishDate |
2018 |
url |
https://dx.doi.org/10.6084/m9.figshare.5797827.v1 https://tandf.figshare.com/articles/An_overview_of_anorthosite-bearing_layered_intrusions_in_the_Archaean_craton_of_southern_West_Greenland_and_the_Superior_Province_of_Canada_implications_for_Archaean_tectonics_and_the_origin_of_megacrystic_plagioclase/5797827/1 |
geographic |
Canada Greenland |
geographic_facet |
Canada Greenland |
genre |
Greenland |
genre_facet |
Greenland |
op_relation |
https://dx.doi.org/10.1080/09853111.2018.1427408 https://dx.doi.org/10.6084/m9.figshare.5797827 |
op_rights |
Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode cc-by-4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.6084/m9.figshare.5797827.v1 https://doi.org/10.1080/09853111.2018.1427408 https://doi.org/10.6084/m9.figshare.5797827 |
_version_ |
1766018015257690112 |