Break-up related 2170–2120 Ma mafic dykes across the North Atlantic craton : Final dismembering of a North Atlantic-Dharwar craton connection?
Progress with supercontinental reconstructions relies on accurate age determinations for continental geological units such as mafic dyke swarms. Here we present zircon and baddeleyite U-Pb ID-TIMS isotope data of six mafic dykes from the Archean North Atlantic craton in present-day southern West and...
Published in: | Precambrian Research |
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Format: | Article in Journal/Newspaper |
Language: | English |
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Online Access: | https://lup.lub.lu.se/record/d79e83e6-c629-43e9-8983-47507cb102aa https://doi.org/10.1016/j.precamres.2018.12.028 |
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ftulundlup:oai:lup.lub.lu.se:d79e83e6-c629-43e9-8983-47507cb102aa 2023-05-15T16:03:42+02:00 Break-up related 2170–2120 Ma mafic dykes across the North Atlantic craton : Final dismembering of a North Atlantic-Dharwar craton connection? Nilsson, Mimmi K.M. Klausen, Martin B. Petersson, Andreas 2019 https://lup.lub.lu.se/record/d79e83e6-c629-43e9-8983-47507cb102aa https://doi.org/10.1016/j.precamres.2018.12.028 eng eng Elsevier https://lup.lub.lu.se/record/d79e83e6-c629-43e9-8983-47507cb102aa http://dx.doi.org/10.1016/j.precamres.2018.12.028 scopus:85059347344 Precambrian Research; 329, pp 70-87 (2019) ISSN: 0301-9268 Geology contributiontojournal/article info:eu-repo/semantics/article text 2019 ftulundlup https://doi.org/10.1016/j.precamres.2018.12.028 2023-02-01T23:36:44Z Progress with supercontinental reconstructions relies on accurate age determinations for continental geological units such as mafic dyke swarms. Here we present zircon and baddeleyite U-Pb ID-TIMS isotope data of six mafic dykes from the Archean North Atlantic craton in present-day southern West and South-East Greenland. Two dykes in southern West Greenland yield crystallization ages of 2021 ± 4 Ma, for the NE-trending Hamborgersund dyke, and 2125 ± 9 Ma, for the E-trending Angissunguaq dyke. Additional age determinations of mafic dykes from South-East Greenland are 2166 ± 8 Ma and 2158 ± 8 Ma for two E–W trending dykes, herein named the Skjoldungen dykes, and 2137 ± 11 and 2124 ± 11 for two ENE and NE trending dykes, respectively. The name Ruinnæsset dykes is proposed for this slightly younger, ca. 2137–2124 Ma, generation of dykes in SE Greenland, and Nuuk dykes for coeval ca. 2125 Ma dykes in SW Greenland. The Skjoldungen and the Ruinnæsset dykes have primordial mantle geochemical signatures, with only minor LILE-enrichments. These signatures differ from other, more ‘lithospheric’ Proterozoic dykes within the region, and may reflect highly attenuated lithospheric extension during their emplacement. Coeval mafic magmatism in North Atlantic and Dharwar cratons suggests that these two fragments coexisted within a common Paleoproterozoic supercraton. A lack of younger age-matches further argue for ca. 2170–2140 Ma rifting and subsequent break-up of this Dharwar-North Atlantic connection, prior to the 2137–2124 Ma emplacement of the Ruinnæsset dykes. Other global age correlations are discussed and a likely paleogeographic reconstruction of North Atlantic craton together with the Dharwar and Superior cratons within a Paleoproterozoic supercraton is presented. Article in Journal/Newspaper East Greenland Greenland North Atlantic Nuuk Lund University Publications (LUP) Greenland Hamborgersund ENVELOPE(-53.050,-53.050,65.650,65.650) Nuuk ENVELOPE(-52.150,-52.150,68.717,68.717) Skjoldungen ENVELOPE(-41.403,-41.403,63.220,63.220) Precambrian Research 329 70 87 |
institution |
Open Polar |
collection |
Lund University Publications (LUP) |
op_collection_id |
ftulundlup |
language |
English |
topic |
Geology |
spellingShingle |
Geology Nilsson, Mimmi K.M. Klausen, Martin B. Petersson, Andreas Break-up related 2170–2120 Ma mafic dykes across the North Atlantic craton : Final dismembering of a North Atlantic-Dharwar craton connection? |
topic_facet |
Geology |
description |
Progress with supercontinental reconstructions relies on accurate age determinations for continental geological units such as mafic dyke swarms. Here we present zircon and baddeleyite U-Pb ID-TIMS isotope data of six mafic dykes from the Archean North Atlantic craton in present-day southern West and South-East Greenland. Two dykes in southern West Greenland yield crystallization ages of 2021 ± 4 Ma, for the NE-trending Hamborgersund dyke, and 2125 ± 9 Ma, for the E-trending Angissunguaq dyke. Additional age determinations of mafic dykes from South-East Greenland are 2166 ± 8 Ma and 2158 ± 8 Ma for two E–W trending dykes, herein named the Skjoldungen dykes, and 2137 ± 11 and 2124 ± 11 for two ENE and NE trending dykes, respectively. The name Ruinnæsset dykes is proposed for this slightly younger, ca. 2137–2124 Ma, generation of dykes in SE Greenland, and Nuuk dykes for coeval ca. 2125 Ma dykes in SW Greenland. The Skjoldungen and the Ruinnæsset dykes have primordial mantle geochemical signatures, with only minor LILE-enrichments. These signatures differ from other, more ‘lithospheric’ Proterozoic dykes within the region, and may reflect highly attenuated lithospheric extension during their emplacement. Coeval mafic magmatism in North Atlantic and Dharwar cratons suggests that these two fragments coexisted within a common Paleoproterozoic supercraton. A lack of younger age-matches further argue for ca. 2170–2140 Ma rifting and subsequent break-up of this Dharwar-North Atlantic connection, prior to the 2137–2124 Ma emplacement of the Ruinnæsset dykes. Other global age correlations are discussed and a likely paleogeographic reconstruction of North Atlantic craton together with the Dharwar and Superior cratons within a Paleoproterozoic supercraton is presented. |
format |
Article in Journal/Newspaper |
author |
Nilsson, Mimmi K.M. Klausen, Martin B. Petersson, Andreas |
author_facet |
Nilsson, Mimmi K.M. Klausen, Martin B. Petersson, Andreas |
author_sort |
Nilsson, Mimmi K.M. |
title |
Break-up related 2170–2120 Ma mafic dykes across the North Atlantic craton : Final dismembering of a North Atlantic-Dharwar craton connection? |
title_short |
Break-up related 2170–2120 Ma mafic dykes across the North Atlantic craton : Final dismembering of a North Atlantic-Dharwar craton connection? |
title_full |
Break-up related 2170–2120 Ma mafic dykes across the North Atlantic craton : Final dismembering of a North Atlantic-Dharwar craton connection? |
title_fullStr |
Break-up related 2170–2120 Ma mafic dykes across the North Atlantic craton : Final dismembering of a North Atlantic-Dharwar craton connection? |
title_full_unstemmed |
Break-up related 2170–2120 Ma mafic dykes across the North Atlantic craton : Final dismembering of a North Atlantic-Dharwar craton connection? |
title_sort |
break-up related 2170–2120 ma mafic dykes across the north atlantic craton : final dismembering of a north atlantic-dharwar craton connection? |
publisher |
Elsevier |
publishDate |
2019 |
url |
https://lup.lub.lu.se/record/d79e83e6-c629-43e9-8983-47507cb102aa https://doi.org/10.1016/j.precamres.2018.12.028 |
long_lat |
ENVELOPE(-53.050,-53.050,65.650,65.650) ENVELOPE(-52.150,-52.150,68.717,68.717) ENVELOPE(-41.403,-41.403,63.220,63.220) |
geographic |
Greenland Hamborgersund Nuuk Skjoldungen |
geographic_facet |
Greenland Hamborgersund Nuuk Skjoldungen |
genre |
East Greenland Greenland North Atlantic Nuuk |
genre_facet |
East Greenland Greenland North Atlantic Nuuk |
op_source |
Precambrian Research; 329, pp 70-87 (2019) ISSN: 0301-9268 |
op_relation |
https://lup.lub.lu.se/record/d79e83e6-c629-43e9-8983-47507cb102aa http://dx.doi.org/10.1016/j.precamres.2018.12.028 scopus:85059347344 |
op_doi |
https://doi.org/10.1016/j.precamres.2018.12.028 |
container_title |
Precambrian Research |
container_volume |
329 |
container_start_page |
70 |
op_container_end_page |
87 |
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1766399392059752448 |