RELICTS OF THE PRIMARY MAGMATIC ACCESSORY SPINELS IN THE ARCHEAN KOMATIITES OF THE EASTERN FENNOSCANDIA
The article presents the results of a complex study of the relicts of the primary magmatic spinels from the Archean (3.0-2.7 Ga) komatiitic series of the greenstone structures of the eastern Fennoscandian Shield. The accessory minerals of the massive and mesocumulate zones of differentiated komatiit...
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ftdoajarticles:oai:doaj.org/article:b9fd302c676a4b15b7c32c90c54a7dc1 2023-05-15T16:11:56+02:00 RELICTS OF THE PRIMARY MAGMATIC ACCESSORY SPINELS IN THE ARCHEAN KOMATIITES OF THE EASTERN FENNOSCANDIA Зоя Павловна Рыбникова Zoya Rybnikova 2015-06-01T00:00:00Z https://doi.org/10.17076/geo141 https://doaj.org/article/b9fd302c676a4b15b7c32c90c54a7dc1 EN RU eng rus Karelian Research Centre of the Russian Academy of Sciences http://journals.krc.karelia.ru/index.php/precambrian/article/view/141 https://doaj.org/toc/1997-3217 https://doaj.org/toc/2312-4504 1997-3217 2312-4504 doi:10.17076/geo141 https://doaj.org/article/b9fd302c676a4b15b7c32c90c54a7dc1 Transactions of the Karelian Research Centre of the Russian Academy of Sciences, Vol 0, Iss 7, Pp 149-163 (2015) хромиты коматииты архей Science Q article 2015 ftdoajarticles https://doi.org/10.17076/geo141 2022-12-31T15:44:18Z The article presents the results of a complex study of the relicts of the primary magmatic spinels from the Archean (3.0-2.7 Ga) komatiitic series of the greenstone structures of the eastern Fennoscandian Shield. The accessory minerals of the massive and mesocumulate zones of differentiated komatiite flows (containing 24-30 wt. % MgO) are analyzed. The coexistence of several generations of spinels including relicts of the primary magmatic chromite-alumochromite (Cr 2 O 3 44.64-51.80, AI 2 O 3 9.39-13.74, #Cr 68.97-78.52, #Mg 3.98-12.14, #Fe <12), which is an equilibrium mineral phase in komatiitic melts crystallizing in the temperature range of 1340-1370 °C after the extraction of olivine, is established in the komatiites. The identified geochemical zoning in the primary spinels is the result of the equilibrium crystallization of komatiitic melt with a gradual decrease in temperature, which leads to the formation of alumochromite-subferrialumochromite solid solutions. It is shown that the metamorphic transformation of rocks at pressure > 5 kbar and temperatures > 500 °C leads to a complete recrystallization of the primary spinels. Article in Journal/Newspaper Fennoscandia Fennoscandian Directory of Open Access Journals: DOAJ Articles Proceedings of the Karelian Research Centre of the Russian Academy of Sciences 7 149 |
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Directory of Open Access Journals: DOAJ Articles |
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хромиты коматииты архей Science Q |
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хромиты коматииты архей Science Q Зоя Павловна Рыбникова Zoya Rybnikova RELICTS OF THE PRIMARY MAGMATIC ACCESSORY SPINELS IN THE ARCHEAN KOMATIITES OF THE EASTERN FENNOSCANDIA |
topic_facet |
хромиты коматииты архей Science Q |
description |
The article presents the results of a complex study of the relicts of the primary magmatic spinels from the Archean (3.0-2.7 Ga) komatiitic series of the greenstone structures of the eastern Fennoscandian Shield. The accessory minerals of the massive and mesocumulate zones of differentiated komatiite flows (containing 24-30 wt. % MgO) are analyzed. The coexistence of several generations of spinels including relicts of the primary magmatic chromite-alumochromite (Cr 2 O 3 44.64-51.80, AI 2 O 3 9.39-13.74, #Cr 68.97-78.52, #Mg 3.98-12.14, #Fe <12), which is an equilibrium mineral phase in komatiitic melts crystallizing in the temperature range of 1340-1370 °C after the extraction of olivine, is established in the komatiites. The identified geochemical zoning in the primary spinels is the result of the equilibrium crystallization of komatiitic melt with a gradual decrease in temperature, which leads to the formation of alumochromite-subferrialumochromite solid solutions. It is shown that the metamorphic transformation of rocks at pressure > 5 kbar and temperatures > 500 °C leads to a complete recrystallization of the primary spinels. |
format |
Article in Journal/Newspaper |
author |
Зоя Павловна Рыбникова Zoya Rybnikova |
author_facet |
Зоя Павловна Рыбникова Zoya Rybnikova |
author_sort |
Зоя Павловна Рыбникова |
title |
RELICTS OF THE PRIMARY MAGMATIC ACCESSORY SPINELS IN THE ARCHEAN KOMATIITES OF THE EASTERN FENNOSCANDIA |
title_short |
RELICTS OF THE PRIMARY MAGMATIC ACCESSORY SPINELS IN THE ARCHEAN KOMATIITES OF THE EASTERN FENNOSCANDIA |
title_full |
RELICTS OF THE PRIMARY MAGMATIC ACCESSORY SPINELS IN THE ARCHEAN KOMATIITES OF THE EASTERN FENNOSCANDIA |
title_fullStr |
RELICTS OF THE PRIMARY MAGMATIC ACCESSORY SPINELS IN THE ARCHEAN KOMATIITES OF THE EASTERN FENNOSCANDIA |
title_full_unstemmed |
RELICTS OF THE PRIMARY MAGMATIC ACCESSORY SPINELS IN THE ARCHEAN KOMATIITES OF THE EASTERN FENNOSCANDIA |
title_sort |
relicts of the primary magmatic accessory spinels in the archean komatiites of the eastern fennoscandia |
publisher |
Karelian Research Centre of the Russian Academy of Sciences |
publishDate |
2015 |
url |
https://doi.org/10.17076/geo141 https://doaj.org/article/b9fd302c676a4b15b7c32c90c54a7dc1 |
genre |
Fennoscandia Fennoscandian |
genre_facet |
Fennoscandia Fennoscandian |
op_source |
Transactions of the Karelian Research Centre of the Russian Academy of Sciences, Vol 0, Iss 7, Pp 149-163 (2015) |
op_relation |
http://journals.krc.karelia.ru/index.php/precambrian/article/view/141 https://doaj.org/toc/1997-3217 https://doaj.org/toc/2312-4504 1997-3217 2312-4504 doi:10.17076/geo141 https://doaj.org/article/b9fd302c676a4b15b7c32c90c54a7dc1 |
op_doi |
https://doi.org/10.17076/geo141 |
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Proceedings of the Karelian Research Centre of the Russian Academy of Sciences |
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