Unreworked Archaean basement and Proterozoic supracrustal rocks from northeastern Disko Bugt, West Greenland: implications for the nature of Proterozoic mobile belts in Greenland
Whole-rock Rb–Sr and Pb–Pb and zircon U–Pb isotope data yield an age of approximately 2800 Ma for the Atâ granite from northeastern Disko Bugt, West Greenland. Field observations and isotope data suggest that the surrounding gneisses were formed by deformation and recrystallization of granitoid rock...
Published in: | Canadian Journal of Earth Sciences |
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1988
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crcansciencepubl:10.1139/e88-072 2023-12-17T10:29:25+01:00 Unreworked Archaean basement and Proterozoic supracrustal rocks from northeastern Disko Bugt, West Greenland: implications for the nature of Proterozoic mobile belts in Greenland Kalsbeek, F. Taylor, P. N. Pidgeon, R. T. 1988 http://dx.doi.org/10.1139/e88-072 http://www.nrcresearchpress.com/doi/pdf/10.1139/e88-072 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Journal of Earth Sciences volume 25, issue 5, page 773-782 ISSN 0008-4077 1480-3313 General Earth and Planetary Sciences journal-article 1988 crcansciencepubl https://doi.org/10.1139/e88-072 2023-11-19T13:38:15Z Whole-rock Rb–Sr and Pb–Pb and zircon U–Pb isotope data yield an age of approximately 2800 Ma for the Atâ granite from northeastern Disko Bugt, West Greenland. Field observations and isotope data suggest that the surrounding gneisses were formed by deformation and recrystallization of granitoid rocks similar to the Atâ granite some 100 Ma after the emplacement of the granite. Rb–Sr whole-rock data on siltstones at low metamorphic grade give an age of 1760 ± 185 Ma, which is interpreted as the time of closure of the isotope systems after metamorphism. The initial 87 Sr/ 86 Sr ratio demonstrates that the sediments were probably deposited during the early Proterozoic.Field observations and isotope data show that Proterozoic (Hudsonian s.l.) deformation and metamorphism were weak in the investigated area. The Archaean basement is well preserved, and the metasediments have well-preserved sedimentary structures. The area lies between the Proterozoic Nagssugtoqidian and Rinkian mobile belts of West Greenland, which are thus separated by an area of Archaean rocks little affected by mid-Proterozoic tectono-thermal events. Thus the two belts form separate tectonic units and do not constitute a single contiguous vast area of Archaean rocks reworked by Proterozoic deforma-tion and metamorphism. It is suggested that the Proterozoic mobile belts of West Greenland are orogenic zones of restricted width (a few hundreds of kilometres) that may be interpreted in terms of modern plate tectonic processes. Article in Journal/Newspaper Disko bugt Greenland Canadian Science Publishing (via Crossref) Greenland Canadian Journal of Earth Sciences 25 5 773 782 |
institution |
Open Polar |
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Canadian Science Publishing (via Crossref) |
op_collection_id |
crcansciencepubl |
language |
English |
topic |
General Earth and Planetary Sciences |
spellingShingle |
General Earth and Planetary Sciences Kalsbeek, F. Taylor, P. N. Pidgeon, R. T. Unreworked Archaean basement and Proterozoic supracrustal rocks from northeastern Disko Bugt, West Greenland: implications for the nature of Proterozoic mobile belts in Greenland |
topic_facet |
General Earth and Planetary Sciences |
description |
Whole-rock Rb–Sr and Pb–Pb and zircon U–Pb isotope data yield an age of approximately 2800 Ma for the Atâ granite from northeastern Disko Bugt, West Greenland. Field observations and isotope data suggest that the surrounding gneisses were formed by deformation and recrystallization of granitoid rocks similar to the Atâ granite some 100 Ma after the emplacement of the granite. Rb–Sr whole-rock data on siltstones at low metamorphic grade give an age of 1760 ± 185 Ma, which is interpreted as the time of closure of the isotope systems after metamorphism. The initial 87 Sr/ 86 Sr ratio demonstrates that the sediments were probably deposited during the early Proterozoic.Field observations and isotope data show that Proterozoic (Hudsonian s.l.) deformation and metamorphism were weak in the investigated area. The Archaean basement is well preserved, and the metasediments have well-preserved sedimentary structures. The area lies between the Proterozoic Nagssugtoqidian and Rinkian mobile belts of West Greenland, which are thus separated by an area of Archaean rocks little affected by mid-Proterozoic tectono-thermal events. Thus the two belts form separate tectonic units and do not constitute a single contiguous vast area of Archaean rocks reworked by Proterozoic deforma-tion and metamorphism. It is suggested that the Proterozoic mobile belts of West Greenland are orogenic zones of restricted width (a few hundreds of kilometres) that may be interpreted in terms of modern plate tectonic processes. |
format |
Article in Journal/Newspaper |
author |
Kalsbeek, F. Taylor, P. N. Pidgeon, R. T. |
author_facet |
Kalsbeek, F. Taylor, P. N. Pidgeon, R. T. |
author_sort |
Kalsbeek, F. |
title |
Unreworked Archaean basement and Proterozoic supracrustal rocks from northeastern Disko Bugt, West Greenland: implications for the nature of Proterozoic mobile belts in Greenland |
title_short |
Unreworked Archaean basement and Proterozoic supracrustal rocks from northeastern Disko Bugt, West Greenland: implications for the nature of Proterozoic mobile belts in Greenland |
title_full |
Unreworked Archaean basement and Proterozoic supracrustal rocks from northeastern Disko Bugt, West Greenland: implications for the nature of Proterozoic mobile belts in Greenland |
title_fullStr |
Unreworked Archaean basement and Proterozoic supracrustal rocks from northeastern Disko Bugt, West Greenland: implications for the nature of Proterozoic mobile belts in Greenland |
title_full_unstemmed |
Unreworked Archaean basement and Proterozoic supracrustal rocks from northeastern Disko Bugt, West Greenland: implications for the nature of Proterozoic mobile belts in Greenland |
title_sort |
unreworked archaean basement and proterozoic supracrustal rocks from northeastern disko bugt, west greenland: implications for the nature of proterozoic mobile belts in greenland |
publisher |
Canadian Science Publishing |
publishDate |
1988 |
url |
http://dx.doi.org/10.1139/e88-072 http://www.nrcresearchpress.com/doi/pdf/10.1139/e88-072 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Disko bugt Greenland |
genre_facet |
Disko bugt Greenland |
op_source |
Canadian Journal of Earth Sciences volume 25, issue 5, page 773-782 ISSN 0008-4077 1480-3313 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/e88-072 |
container_title |
Canadian Journal of Earth Sciences |
container_volume |
25 |
container_issue |
5 |
container_start_page |
773 |
op_container_end_page |
782 |
_version_ |
1785581795603906560 |