Remnants of arc-related Mesoarchaean oceanic crust in the Tartoq Group of SW Greenland
The Tartoq Group, located in SW Greenland, consists of supracrustal rocks of mainly tholeiitic basaltic composition, including pillow lavas, sills/dykes and gabbros, as well as ultramafic rocks. Metamorphic grade ranges from greenschist fades to granulite facies. The Tartoq Group crops out as a seri...
Published in: | Gondwana Research |
---|---|
Main Authors: | , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Elsevier
2013
|
Subjects: | |
Online Access: | https://lup.lub.lu.se/record/3671509 https://doi.org/10.1016/j.gr.2011.11.006 |
id |
ftulundlup:oai:lup.lub.lu.se:fffbd9de-cae1-47cf-95ee-c1464448a392 |
---|---|
record_format |
openpolar |
spelling |
ftulundlup:oai:lup.lub.lu.se:fffbd9de-cae1-47cf-95ee-c1464448a392 2023-05-15T16:27:48+02:00 Remnants of arc-related Mesoarchaean oceanic crust in the Tartoq Group of SW Greenland Szilas, Kristoffer Van Hinsberg, Vincent J. Kisters, Alex. F. M. Hoffmann, J. Elis Windley, Brian F. Kokfelt, Thomas F. Scherstén, Anders Frei, Robert Rosing, Minik T. Muenker, Carsten 2013 https://lup.lub.lu.se/record/3671509 https://doi.org/10.1016/j.gr.2011.11.006 eng eng Elsevier https://lup.lub.lu.se/record/3671509 http://dx.doi.org/10.1016/j.gr.2011.11.006 wos:000315078500005 scopus:84871935469 Gondwana Research; 23(2), pp 436-451 (2013) ISSN: 1342-937X Geology Archaean Greenland Tartoq Group Geochronology Supracrustal belt Oceanic crust contributiontojournal/article info:eu-repo/semantics/article text 2013 ftulundlup https://doi.org/10.1016/j.gr.2011.11.006 2023-02-01T23:33:06Z The Tartoq Group, located in SW Greenland, consists of supracrustal rocks of mainly tholeiitic basaltic composition, including pillow lavas, sills/dykes and gabbros, as well as ultramafic rocks. Metamorphic grade ranges from greenschist fades to granulite facies. The Tartoq Group crops out as a series of blocks and slivers that are imbricated with originally intrusive Mesoarchaean TTG orthogneisses. The supracrustal rocks form part of a SE vergent fold and thrust belt consistent with the imbrication of TTG gneisses and supracrustal rocks along a convergent margin. LA-ICP-MS U-Pb zircon dating of an intrusive TTG sheet yields a minimum age of 2986 +/- 4 Ma for the Tartoq Group. This age is consistent with MC-ICP-MS Lu-Hf and Sm-Nd isotopic whole-rock data for mafic samples from different blocks of the Tartoq Group, which yield errorchron ages of 3189 +/- 65 Ma and 3068 +/- 220 Ma, respectively. The mafic supracrustal rocks of the Tartoq Group have chondrite-normalized REE patterns with La-CN/Sm-CN of 0.67-1.96 and rather flat primitive mantle-normalized multi-element patterns, except for scattered LILE contents, and generally negative Nb-anomalies with Nb/Nb* of 0.26-1.31. Th/Yb varies between 0.06 and 0.47 and Nb/Yb between 0.45 and 4.4 indicative of an arc affinity when compared to rocks from modern settings. The similar geochemistry of the different lithological units, together with their coeval formation, as evident from trace element geochemical trends, supports a co-magmatic origin for the rock assemblage and their formation as imbricated relics of oceanic crust Accordingly, we propose that the Tartoq Group represents remnants of Mesoarchaean oceanic crust, which formed in a suprasubduction zone geodynamic environment (C) 2011 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved. Article in Journal/Newspaper Greenland Lund University Publications (LUP) Greenland Gondwana Research 23 2 436 451 |
institution |
Open Polar |
collection |
Lund University Publications (LUP) |
op_collection_id |
ftulundlup |
language |
English |
topic |
Geology Archaean Greenland Tartoq Group Geochronology Supracrustal belt Oceanic crust |
spellingShingle |
Geology Archaean Greenland Tartoq Group Geochronology Supracrustal belt Oceanic crust Szilas, Kristoffer Van Hinsberg, Vincent J. Kisters, Alex. F. M. Hoffmann, J. Elis Windley, Brian F. Kokfelt, Thomas F. Scherstén, Anders Frei, Robert Rosing, Minik T. Muenker, Carsten Remnants of arc-related Mesoarchaean oceanic crust in the Tartoq Group of SW Greenland |
topic_facet |
Geology Archaean Greenland Tartoq Group Geochronology Supracrustal belt Oceanic crust |
description |
The Tartoq Group, located in SW Greenland, consists of supracrustal rocks of mainly tholeiitic basaltic composition, including pillow lavas, sills/dykes and gabbros, as well as ultramafic rocks. Metamorphic grade ranges from greenschist fades to granulite facies. The Tartoq Group crops out as a series of blocks and slivers that are imbricated with originally intrusive Mesoarchaean TTG orthogneisses. The supracrustal rocks form part of a SE vergent fold and thrust belt consistent with the imbrication of TTG gneisses and supracrustal rocks along a convergent margin. LA-ICP-MS U-Pb zircon dating of an intrusive TTG sheet yields a minimum age of 2986 +/- 4 Ma for the Tartoq Group. This age is consistent with MC-ICP-MS Lu-Hf and Sm-Nd isotopic whole-rock data for mafic samples from different blocks of the Tartoq Group, which yield errorchron ages of 3189 +/- 65 Ma and 3068 +/- 220 Ma, respectively. The mafic supracrustal rocks of the Tartoq Group have chondrite-normalized REE patterns with La-CN/Sm-CN of 0.67-1.96 and rather flat primitive mantle-normalized multi-element patterns, except for scattered LILE contents, and generally negative Nb-anomalies with Nb/Nb* of 0.26-1.31. Th/Yb varies between 0.06 and 0.47 and Nb/Yb between 0.45 and 4.4 indicative of an arc affinity when compared to rocks from modern settings. The similar geochemistry of the different lithological units, together with their coeval formation, as evident from trace element geochemical trends, supports a co-magmatic origin for the rock assemblage and their formation as imbricated relics of oceanic crust Accordingly, we propose that the Tartoq Group represents remnants of Mesoarchaean oceanic crust, which formed in a suprasubduction zone geodynamic environment (C) 2011 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved. |
format |
Article in Journal/Newspaper |
author |
Szilas, Kristoffer Van Hinsberg, Vincent J. Kisters, Alex. F. M. Hoffmann, J. Elis Windley, Brian F. Kokfelt, Thomas F. Scherstén, Anders Frei, Robert Rosing, Minik T. Muenker, Carsten |
author_facet |
Szilas, Kristoffer Van Hinsberg, Vincent J. Kisters, Alex. F. M. Hoffmann, J. Elis Windley, Brian F. Kokfelt, Thomas F. Scherstén, Anders Frei, Robert Rosing, Minik T. Muenker, Carsten |
author_sort |
Szilas, Kristoffer |
title |
Remnants of arc-related Mesoarchaean oceanic crust in the Tartoq Group of SW Greenland |
title_short |
Remnants of arc-related Mesoarchaean oceanic crust in the Tartoq Group of SW Greenland |
title_full |
Remnants of arc-related Mesoarchaean oceanic crust in the Tartoq Group of SW Greenland |
title_fullStr |
Remnants of arc-related Mesoarchaean oceanic crust in the Tartoq Group of SW Greenland |
title_full_unstemmed |
Remnants of arc-related Mesoarchaean oceanic crust in the Tartoq Group of SW Greenland |
title_sort |
remnants of arc-related mesoarchaean oceanic crust in the tartoq group of sw greenland |
publisher |
Elsevier |
publishDate |
2013 |
url |
https://lup.lub.lu.se/record/3671509 https://doi.org/10.1016/j.gr.2011.11.006 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland |
genre_facet |
Greenland |
op_source |
Gondwana Research; 23(2), pp 436-451 (2013) ISSN: 1342-937X |
op_relation |
https://lup.lub.lu.se/record/3671509 http://dx.doi.org/10.1016/j.gr.2011.11.006 wos:000315078500005 scopus:84871935469 |
op_doi |
https://doi.org/10.1016/j.gr.2011.11.006 |
container_title |
Gondwana Research |
container_volume |
23 |
container_issue |
2 |
container_start_page |
436 |
op_container_end_page |
451 |
_version_ |
1766017309487398912 |