U-Pb zircon geochronology of selected Archaean migmatites in eastern Finland
U-Pb SIMS data on eight samples (four mesosome-leucosome pairs) from migmatites in gneiss complexes are presented from the western part of the Archaean Karelian craton, eastern Finland. Most zircon grains in the mesosomes yield ages between 2.84 Ga and 2.79 Ga, with cores of 2.94 Ga in one sample. A...
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ftdoajarticles:oai:doaj.org/article:6651d4c674a84af19020284ea85ce6b3 2023-05-15T17:00:05+02:00 U-Pb zircon geochronology of selected Archaean migmatites in eastern Finland A. Käpyaho P. Hölttä M.J. Whitehouse 2007-06-01T00:00:00Z https://doi.org/10.17741/bgsf/79.1.005 https://doaj.org/article/6651d4c674a84af19020284ea85ce6b3 EN eng Geological Society of Finland http://www.geologinenseura.fi/bulletin/Volume79/Kapyaho_etal_2007.pdf https://doaj.org/toc/0367-5211 https://doaj.org/toc/1799-4632 doi:10.17741/bgsf/79.1.005 0367-5211 1799-4632 https://doaj.org/article/6651d4c674a84af19020284ea85ce6b3 Bulletin of the Geological Society of Finland, Vol 79, Iss 1, Pp 95-115 (2007) migmatites metamorphism migmatization absolute age U/Pb zircon Archean Kuhmo Lieksa Finland Geology QE1-996.5 article 2007 ftdoajarticles https://doi.org/10.17741/bgsf/79.1.005 2022-12-30T22:18:55Z U-Pb SIMS data on eight samples (four mesosome-leucosome pairs) from migmatites in gneiss complexes are presented from the western part of the Archaean Karelian craton, eastern Finland. Most zircon grains in the mesosomes yield ages between 2.84 Ga and 2.79 Ga, with cores of 2.94 Ga in one sample. Age data imply that migmatite mesosome protoliths were generated at broadly the same time as metamorphosed volcanic rocks in the adjacent Kuhmo-Suomussalmi-Tipasjärvi greenstone belt, suggesting that at least some of the mesosomes may represent migmatised equivalents of the greenstone belt rocks. Two separate events of metamorphic zircon growth are recognised from different samples: the first occurred between 2.84 Ga and 2.81 Ga, and the second between 2.73 Ga and 2.70 Ga. The latter event is considered to have led up to a prolonged period of partial melting, as is suggested by the zircons dated from the leucosomes. Scattered age data, inheritance and the large number of discordant data prevented establishing accurate leucosome generation ages. Consequently, the age data are considered to support the previously proposed hypothesis that the Archaean Karelian craton was formed after accumulation of separate tectonic entities having variable ages. Article in Journal/Newspaper karelia* karelian Directory of Open Access Journals: DOAJ Articles Bulletin of the Geological Society of Finland 79 1 95 115 |
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Directory of Open Access Journals: DOAJ Articles |
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English |
topic |
migmatites metamorphism migmatization absolute age U/Pb zircon Archean Kuhmo Lieksa Finland Geology QE1-996.5 |
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migmatites metamorphism migmatization absolute age U/Pb zircon Archean Kuhmo Lieksa Finland Geology QE1-996.5 A. Käpyaho P. Hölttä M.J. Whitehouse U-Pb zircon geochronology of selected Archaean migmatites in eastern Finland |
topic_facet |
migmatites metamorphism migmatization absolute age U/Pb zircon Archean Kuhmo Lieksa Finland Geology QE1-996.5 |
description |
U-Pb SIMS data on eight samples (four mesosome-leucosome pairs) from migmatites in gneiss complexes are presented from the western part of the Archaean Karelian craton, eastern Finland. Most zircon grains in the mesosomes yield ages between 2.84 Ga and 2.79 Ga, with cores of 2.94 Ga in one sample. Age data imply that migmatite mesosome protoliths were generated at broadly the same time as metamorphosed volcanic rocks in the adjacent Kuhmo-Suomussalmi-Tipasjärvi greenstone belt, suggesting that at least some of the mesosomes may represent migmatised equivalents of the greenstone belt rocks. Two separate events of metamorphic zircon growth are recognised from different samples: the first occurred between 2.84 Ga and 2.81 Ga, and the second between 2.73 Ga and 2.70 Ga. The latter event is considered to have led up to a prolonged period of partial melting, as is suggested by the zircons dated from the leucosomes. Scattered age data, inheritance and the large number of discordant data prevented establishing accurate leucosome generation ages. Consequently, the age data are considered to support the previously proposed hypothesis that the Archaean Karelian craton was formed after accumulation of separate tectonic entities having variable ages. |
format |
Article in Journal/Newspaper |
author |
A. Käpyaho P. Hölttä M.J. Whitehouse |
author_facet |
A. Käpyaho P. Hölttä M.J. Whitehouse |
author_sort |
A. Käpyaho |
title |
U-Pb zircon geochronology of selected Archaean migmatites in eastern Finland |
title_short |
U-Pb zircon geochronology of selected Archaean migmatites in eastern Finland |
title_full |
U-Pb zircon geochronology of selected Archaean migmatites in eastern Finland |
title_fullStr |
U-Pb zircon geochronology of selected Archaean migmatites in eastern Finland |
title_full_unstemmed |
U-Pb zircon geochronology of selected Archaean migmatites in eastern Finland |
title_sort |
u-pb zircon geochronology of selected archaean migmatites in eastern finland |
publisher |
Geological Society of Finland |
publishDate |
2007 |
url |
https://doi.org/10.17741/bgsf/79.1.005 https://doaj.org/article/6651d4c674a84af19020284ea85ce6b3 |
genre |
karelia* karelian |
genre_facet |
karelia* karelian |
op_source |
Bulletin of the Geological Society of Finland, Vol 79, Iss 1, Pp 95-115 (2007) |
op_relation |
http://www.geologinenseura.fi/bulletin/Volume79/Kapyaho_etal_2007.pdf https://doaj.org/toc/0367-5211 https://doaj.org/toc/1799-4632 doi:10.17741/bgsf/79.1.005 0367-5211 1799-4632 https://doaj.org/article/6651d4c674a84af19020284ea85ce6b3 |
op_doi |
https://doi.org/10.17741/bgsf/79.1.005 |
container_title |
Bulletin of the Geological Society of Finland |
container_volume |
79 |
container_issue |
1 |
container_start_page |
95 |
op_container_end_page |
115 |
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1766052717152698368 |