Garnet and zircon geochronology of the Paleoproterozoic Kuru-Vaara eclogites, northern Belomorian Province, Fennoscandian Shield
The Belomorian Province of the Fennoscandian Shield exposes numerous Precambrian eclogites, which makes it significant for the study of early tectonic processes. The age of these eclogites has been discussed for more than 15 years and regarded as either Archean or Paleoproterozoic. In the Kuru-Vaara...
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ftdatacite:10.48350/149541 2023-05-15T16:12:54+02:00 Garnet and zircon geochronology of the Paleoproterozoic Kuru-Vaara eclogites, northern Belomorian Province, Fennoscandian Shield Melnik, A Skublov, S. Rubatto, Daniela Müller, D. Li, Xian-Hua Li, Qiuli Berezin, A. V. Herwartz, Daniel Machevariani, M. 2021 https://dx.doi.org/10.48350/149541 https://boris.unibe.ch/149541/ unknown Elsevier embargoed access Creative Commons Attribution Non Commercial No Derivatives 4.0 International https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode cc-by-nc-nd-4.0 publisher holds copyright http://purl.org/coar/access_right/c_f1cf CC-BY-NC-ND 550 Earth sciences & geology Text article-journal journal article ScholarlyArticle 2021 ftdatacite https://doi.org/10.48350/149541 2021-11-05T12:55:41Z The Belomorian Province of the Fennoscandian Shield exposes numerous Precambrian eclogites, which makes it significant for the study of early tectonic processes. The age of these eclogites has been discussed for more than 15 years and regarded as either Archean or Paleoproterozoic. In the Kuru-Vaara quarry within the northern Belomorian Province, the eclogitic assemblage is preserved in concordant mafic boudins in felsic gneisses and a partially eclogitized gabbro-norite dike cutting discordantly through the gneiss fabric. Both eclogite types pre-serve zircon cores with a magmatic geochemical signature that yield protolith ages of ca. 2.88 Ga for a mafic boudin and ca. 2.44 Ga for the eclogitized gabbro-norite. Ca. 1.9 Ga zircon rims and grains from the eclogites show low Th/U ratio and HREE depletion, reflecting the growth of metamorphic zircon in equilibrium with garnet. In the eclogite boudin, the Archean zircon cores yield δ18O =5.1–5.9‰ typical of mantle melts; the oxygen isotope composition of garnet (δ18O =4.0–5.0‰) is in equilibrium with that of the 1.9 Ga zircon (δ18O =4.5–5.4‰). Garnet Lu-Hf geochronology coupled with U-Pb zircon geochronology constrains prograde meta-morphism for the Kuru-Vaara eclogites at 1.92–1.89 Ga. Mineral inclusions of garnet, zoisite, plagioclase, kyanite, amphibole, quartz, and low-Na clinopyroxene in ca. 1.9 Ga zircon from the eclogite boudin imply epidote–amphibolite/amphibolite facies conditions for the prograde metamorphism. All data point to a Paleo-proterozoic age of the eclogite facies metamorphism Text Fennoscandian DataCite Metadata Store (German National Library of Science and Technology) Vaara ENVELOPE(24.886,24.886,67.360,67.360) |
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550 Earth sciences & geology |
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550 Earth sciences & geology Melnik, A Skublov, S. Rubatto, Daniela Müller, D. Li, Xian-Hua Li, Qiuli Berezin, A. V. Herwartz, Daniel Machevariani, M. Garnet and zircon geochronology of the Paleoproterozoic Kuru-Vaara eclogites, northern Belomorian Province, Fennoscandian Shield |
topic_facet |
550 Earth sciences & geology |
description |
The Belomorian Province of the Fennoscandian Shield exposes numerous Precambrian eclogites, which makes it significant for the study of early tectonic processes. The age of these eclogites has been discussed for more than 15 years and regarded as either Archean or Paleoproterozoic. In the Kuru-Vaara quarry within the northern Belomorian Province, the eclogitic assemblage is preserved in concordant mafic boudins in felsic gneisses and a partially eclogitized gabbro-norite dike cutting discordantly through the gneiss fabric. Both eclogite types pre-serve zircon cores with a magmatic geochemical signature that yield protolith ages of ca. 2.88 Ga for a mafic boudin and ca. 2.44 Ga for the eclogitized gabbro-norite. Ca. 1.9 Ga zircon rims and grains from the eclogites show low Th/U ratio and HREE depletion, reflecting the growth of metamorphic zircon in equilibrium with garnet. In the eclogite boudin, the Archean zircon cores yield δ18O =5.1–5.9‰ typical of mantle melts; the oxygen isotope composition of garnet (δ18O =4.0–5.0‰) is in equilibrium with that of the 1.9 Ga zircon (δ18O =4.5–5.4‰). Garnet Lu-Hf geochronology coupled with U-Pb zircon geochronology constrains prograde meta-morphism for the Kuru-Vaara eclogites at 1.92–1.89 Ga. Mineral inclusions of garnet, zoisite, plagioclase, kyanite, amphibole, quartz, and low-Na clinopyroxene in ca. 1.9 Ga zircon from the eclogite boudin imply epidote–amphibolite/amphibolite facies conditions for the prograde metamorphism. All data point to a Paleo-proterozoic age of the eclogite facies metamorphism |
format |
Text |
author |
Melnik, A Skublov, S. Rubatto, Daniela Müller, D. Li, Xian-Hua Li, Qiuli Berezin, A. V. Herwartz, Daniel Machevariani, M. |
author_facet |
Melnik, A Skublov, S. Rubatto, Daniela Müller, D. Li, Xian-Hua Li, Qiuli Berezin, A. V. Herwartz, Daniel Machevariani, M. |
author_sort |
Melnik, A |
title |
Garnet and zircon geochronology of the Paleoproterozoic Kuru-Vaara eclogites, northern Belomorian Province, Fennoscandian Shield |
title_short |
Garnet and zircon geochronology of the Paleoproterozoic Kuru-Vaara eclogites, northern Belomorian Province, Fennoscandian Shield |
title_full |
Garnet and zircon geochronology of the Paleoproterozoic Kuru-Vaara eclogites, northern Belomorian Province, Fennoscandian Shield |
title_fullStr |
Garnet and zircon geochronology of the Paleoproterozoic Kuru-Vaara eclogites, northern Belomorian Province, Fennoscandian Shield |
title_full_unstemmed |
Garnet and zircon geochronology of the Paleoproterozoic Kuru-Vaara eclogites, northern Belomorian Province, Fennoscandian Shield |
title_sort |
garnet and zircon geochronology of the paleoproterozoic kuru-vaara eclogites, northern belomorian province, fennoscandian shield |
publisher |
Elsevier |
publishDate |
2021 |
url |
https://dx.doi.org/10.48350/149541 https://boris.unibe.ch/149541/ |
long_lat |
ENVELOPE(24.886,24.886,67.360,67.360) |
geographic |
Vaara |
geographic_facet |
Vaara |
genre |
Fennoscandian |
genre_facet |
Fennoscandian |
op_rights |
embargoed access Creative Commons Attribution Non Commercial No Derivatives 4.0 International https://creativecommons.org/licenses/by-nc-nd/4.0/legalcode cc-by-nc-nd-4.0 publisher holds copyright http://purl.org/coar/access_right/c_f1cf |
op_rightsnorm |
CC-BY-NC-ND |
op_doi |
https://doi.org/10.48350/149541 |
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1765998512763305984 |