Setting of the ~2560 Ma Qôrqut Granite Complex in the Archean crustal evolution of Southern West Greenland
The Archean gneiss complex of West Greenland contains packages of unrelated rocks created during relatively short periods of time in arc-like magmatic environments, and having similarities to rocks formed at Phanerozoic convergent plate boundaries. The terranes of new Archean crust were amalgamated...
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Online Access: | http://nora.nerc.ac.uk/id/eprint/14831/ https://nora.nerc.ac.uk/id/eprint/14831/1/Nutman-et-al-revised-complete.pdf http://www.ajsonline.org/ |
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ftnerc:oai:nora.nerc.ac.uk:14831 2023-05-15T16:27:18+02:00 Setting of the ~2560 Ma Qôrqut Granite Complex in the Archean crustal evolution of Southern West Greenland Nutman, Allan P. Friend, Clark R.L. Hiess, Joe 2011 text http://nora.nerc.ac.uk/id/eprint/14831/ https://nora.nerc.ac.uk/id/eprint/14831/1/Nutman-et-al-revised-complete.pdf http://www.ajsonline.org/ en eng https://nora.nerc.ac.uk/id/eprint/14831/1/Nutman-et-al-revised-complete.pdf Nutman, Allan P.; Friend, Clark R.L.; Hiess, Joe. 2011 Setting of the ~2560 Ma Qôrqut Granite Complex in the Archean crustal evolution of Southern West Greenland. American Journal of Science, 310 (9). 1081-1114. https://doi.org/10.2475/09.2010.12 <https://doi.org/10.2475/09.2010.12> Publication - Article PeerReviewed 2011 ftnerc https://doi.org/10.2475/09.2010.12 2023-02-04T19:29:27Z The Archean gneiss complex of West Greenland contains packages of unrelated rocks created during relatively short periods of time in arc-like magmatic environments, and having similarities to rocks formed at Phanerozoic convergent plate boundaries. The terranes of new Archean crust were amalgamated by collisional orogeny and then partitioned by post-assembly tectonic processes. Having summarized the origin of West Greenland Archean crust in arc-like environments, this paper then focuses on new data concerning the latest Neoarchean post terrane-assembly "intra-continental" tectonic and magmatic evolution of the region. Following the youngest documented high pressure metamorphism in a clockwise P-T-t loop at 2650 Ma, attributed to tectonic thickening of the crust, there is in West Greenland a 150 million year record of intermittent production of crustally-derived granite, shearing and folding under amphibolite facies conditions. This is exemplified by the SSW-NNE orientated Neoarchean Qôrqut Granite Complex (QGC) which forms a myriad of closely spaced coeval sheets NE of Nuuk town. SHRIMP U-Pb zircon dating of a homogeneous gray granite sheet gives a magmatic age of 2561±11 Ma, with 3800 to 3600 and 3070 to 2970 Ma zircon xenocrysts. The >40 km long Fjringehavn straight belt, a lower amphibolite-facies vertical shear zone, runs from the QGC's SE margin and contains strongly deformed granite sheets with a U-Pb zircon age of 2565±8 Ma but is cut by undeformed granite sheets dated at 2555±12 Ma. The >60 km long Ivisaartoq fault consisting of lowermost amphibolite-facies mylonite runs from the northwestern end of the main mass of granite. It formed post-2630 Ma, because granites of that age are truncated by it. Near the QGC's northeastern extent, 2559±3 Ma granitic lithons in a folded mylonite are cut by 2521±72 Ma granite sheets. At a deep structural level at the northern end of the QGC, deformed granitic neosomes give ages of 2567±9 and 2563±5 Ma. Therefore, at 2560 Ma, the ages within error for strongly ... Article in Journal/Newspaper Greenland Nuuk Natural Environment Research Council: NERC Open Research Archive Greenland Ivisaartoq ENVELOPE(-49.917,-49.917,64.767,64.767) Nuuk ENVELOPE(-52.150,-52.150,68.717,68.717) American Journal of Science 310 9 1081 1114 |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
The Archean gneiss complex of West Greenland contains packages of unrelated rocks created during relatively short periods of time in arc-like magmatic environments, and having similarities to rocks formed at Phanerozoic convergent plate boundaries. The terranes of new Archean crust were amalgamated by collisional orogeny and then partitioned by post-assembly tectonic processes. Having summarized the origin of West Greenland Archean crust in arc-like environments, this paper then focuses on new data concerning the latest Neoarchean post terrane-assembly "intra-continental" tectonic and magmatic evolution of the region. Following the youngest documented high pressure metamorphism in a clockwise P-T-t loop at 2650 Ma, attributed to tectonic thickening of the crust, there is in West Greenland a 150 million year record of intermittent production of crustally-derived granite, shearing and folding under amphibolite facies conditions. This is exemplified by the SSW-NNE orientated Neoarchean Qôrqut Granite Complex (QGC) which forms a myriad of closely spaced coeval sheets NE of Nuuk town. SHRIMP U-Pb zircon dating of a homogeneous gray granite sheet gives a magmatic age of 2561±11 Ma, with 3800 to 3600 and 3070 to 2970 Ma zircon xenocrysts. The >40 km long Fjringehavn straight belt, a lower amphibolite-facies vertical shear zone, runs from the QGC's SE margin and contains strongly deformed granite sheets with a U-Pb zircon age of 2565±8 Ma but is cut by undeformed granite sheets dated at 2555±12 Ma. The >60 km long Ivisaartoq fault consisting of lowermost amphibolite-facies mylonite runs from the northwestern end of the main mass of granite. It formed post-2630 Ma, because granites of that age are truncated by it. Near the QGC's northeastern extent, 2559±3 Ma granitic lithons in a folded mylonite are cut by 2521±72 Ma granite sheets. At a deep structural level at the northern end of the QGC, deformed granitic neosomes give ages of 2567±9 and 2563±5 Ma. Therefore, at 2560 Ma, the ages within error for strongly ... |
format |
Article in Journal/Newspaper |
author |
Nutman, Allan P. Friend, Clark R.L. Hiess, Joe |
spellingShingle |
Nutman, Allan P. Friend, Clark R.L. Hiess, Joe Setting of the ~2560 Ma Qôrqut Granite Complex in the Archean crustal evolution of Southern West Greenland |
author_facet |
Nutman, Allan P. Friend, Clark R.L. Hiess, Joe |
author_sort |
Nutman, Allan P. |
title |
Setting of the ~2560 Ma Qôrqut Granite Complex in the Archean crustal evolution of Southern West Greenland |
title_short |
Setting of the ~2560 Ma Qôrqut Granite Complex in the Archean crustal evolution of Southern West Greenland |
title_full |
Setting of the ~2560 Ma Qôrqut Granite Complex in the Archean crustal evolution of Southern West Greenland |
title_fullStr |
Setting of the ~2560 Ma Qôrqut Granite Complex in the Archean crustal evolution of Southern West Greenland |
title_full_unstemmed |
Setting of the ~2560 Ma Qôrqut Granite Complex in the Archean crustal evolution of Southern West Greenland |
title_sort |
setting of the ~2560 ma qôrqut granite complex in the archean crustal evolution of southern west greenland |
publishDate |
2011 |
url |
http://nora.nerc.ac.uk/id/eprint/14831/ https://nora.nerc.ac.uk/id/eprint/14831/1/Nutman-et-al-revised-complete.pdf http://www.ajsonline.org/ |
long_lat |
ENVELOPE(-49.917,-49.917,64.767,64.767) ENVELOPE(-52.150,-52.150,68.717,68.717) |
geographic |
Greenland Ivisaartoq Nuuk |
geographic_facet |
Greenland Ivisaartoq Nuuk |
genre |
Greenland Nuuk |
genre_facet |
Greenland Nuuk |
op_relation |
https://nora.nerc.ac.uk/id/eprint/14831/1/Nutman-et-al-revised-complete.pdf Nutman, Allan P.; Friend, Clark R.L.; Hiess, Joe. 2011 Setting of the ~2560 Ma Qôrqut Granite Complex in the Archean crustal evolution of Southern West Greenland. American Journal of Science, 310 (9). 1081-1114. https://doi.org/10.2475/09.2010.12 <https://doi.org/10.2475/09.2010.12> |
op_doi |
https://doi.org/10.2475/09.2010.12 |
container_title |
American Journal of Science |
container_volume |
310 |
container_issue |
9 |
container_start_page |
1081 |
op_container_end_page |
1114 |
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1766016443850162176 |