Ti-Nb Mineralization of Late Carbonatites and Role of Fluids in Its Formation: Petyayan-Vara Rare-Earth Carbonatites (Vuoriyarvi Massif, Russia)
This article is devoted to the geology of titanium-rich varieties of the Petyayan-Vara rare-earth dolomitic carbonatites in Vuoriyarvi, Northwest Russia. Analogues of these varieties are present in many carbonatite complexes. The aim of this study was to investigate the behavior of high field streng...
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ftdoajarticles:oai:doaj.org/article:20a07cb7f2cb40d2a86cb2e534ae038a 2023-05-15T17:46:05+02:00 Ti-Nb Mineralization of Late Carbonatites and Role of Fluids in Its Formation: Petyayan-Vara Rare-Earth Carbonatites (Vuoriyarvi Massif, Russia) Evgeniy Kozlov Ekaterina Fomina Mikhail Sidorov Vladimir Shilovskikh 2018-07-01T00:00:00Z https://doi.org/10.3390/geosciences8080281 https://doaj.org/article/20a07cb7f2cb40d2a86cb2e534ae038a EN eng MDPI AG http://www.mdpi.com/2076-3263/8/8/281 https://doaj.org/toc/2076-3263 2076-3263 doi:10.3390/geosciences8080281 https://doaj.org/article/20a07cb7f2cb40d2a86cb2e534ae038a Geosciences, Vol 8, Iss 8, p 281 (2018) metasomatism brookite anatase pyrochlore niobium carbonatites Vuoriyarvi massif Geology QE1-996.5 article 2018 ftdoajarticles https://doi.org/10.3390/geosciences8080281 2022-12-31T16:24:07Z This article is devoted to the geology of titanium-rich varieties of the Petyayan-Vara rare-earth dolomitic carbonatites in Vuoriyarvi, Northwest Russia. Analogues of these varieties are present in many carbonatite complexes. The aim of this study was to investigate the behavior of high field strength elements during the late stages of carbonatite formation. We conducted a multilateral study of titanium- and niobium-bearing minerals, including a petrographic study, Raman spectroscopy, microprobe determination of chemical composition, and electron backscatter diffraction. Three TiO2-polymorphs (anatase, brookite and rutile) and three pyrochlore group members (hydroxycalcio-, fluorcalcio-, and kenoplumbopyrochlore) were found to coexist in the studied rocks. The formation of these minerals occurred in several stages. First, Nb-poor Ti-oxides were formed in the fluid-permeable zones. The overprinting of this assemblage by residual fluids led to the generation of Nb-rich brookite (the main niobium concentrator in the Petyayan-Vara) and minerals of the pyrochlore group. This process also caused niobium enrichment with of early generations of Ti oxides. Our results indicate abrupt changes in the physicochemical parameters at the late hydro (carbo) thermal stage of the carbonatite formation and high migration capacity of Ti and Nb under these conditions. The metasomatism was accompanied by the separation of these elements. Article in Journal/Newspaper Northwest Russia Directory of Open Access Journals: DOAJ Articles Geosciences 8 8 281 |
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metasomatism brookite anatase pyrochlore niobium carbonatites Vuoriyarvi massif Geology QE1-996.5 |
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metasomatism brookite anatase pyrochlore niobium carbonatites Vuoriyarvi massif Geology QE1-996.5 Evgeniy Kozlov Ekaterina Fomina Mikhail Sidorov Vladimir Shilovskikh Ti-Nb Mineralization of Late Carbonatites and Role of Fluids in Its Formation: Petyayan-Vara Rare-Earth Carbonatites (Vuoriyarvi Massif, Russia) |
topic_facet |
metasomatism brookite anatase pyrochlore niobium carbonatites Vuoriyarvi massif Geology QE1-996.5 |
description |
This article is devoted to the geology of titanium-rich varieties of the Petyayan-Vara rare-earth dolomitic carbonatites in Vuoriyarvi, Northwest Russia. Analogues of these varieties are present in many carbonatite complexes. The aim of this study was to investigate the behavior of high field strength elements during the late stages of carbonatite formation. We conducted a multilateral study of titanium- and niobium-bearing minerals, including a petrographic study, Raman spectroscopy, microprobe determination of chemical composition, and electron backscatter diffraction. Three TiO2-polymorphs (anatase, brookite and rutile) and three pyrochlore group members (hydroxycalcio-, fluorcalcio-, and kenoplumbopyrochlore) were found to coexist in the studied rocks. The formation of these minerals occurred in several stages. First, Nb-poor Ti-oxides were formed in the fluid-permeable zones. The overprinting of this assemblage by residual fluids led to the generation of Nb-rich brookite (the main niobium concentrator in the Petyayan-Vara) and minerals of the pyrochlore group. This process also caused niobium enrichment with of early generations of Ti oxides. Our results indicate abrupt changes in the physicochemical parameters at the late hydro (carbo) thermal stage of the carbonatite formation and high migration capacity of Ti and Nb under these conditions. The metasomatism was accompanied by the separation of these elements. |
format |
Article in Journal/Newspaper |
author |
Evgeniy Kozlov Ekaterina Fomina Mikhail Sidorov Vladimir Shilovskikh |
author_facet |
Evgeniy Kozlov Ekaterina Fomina Mikhail Sidorov Vladimir Shilovskikh |
author_sort |
Evgeniy Kozlov |
title |
Ti-Nb Mineralization of Late Carbonatites and Role of Fluids in Its Formation: Petyayan-Vara Rare-Earth Carbonatites (Vuoriyarvi Massif, Russia) |
title_short |
Ti-Nb Mineralization of Late Carbonatites and Role of Fluids in Its Formation: Petyayan-Vara Rare-Earth Carbonatites (Vuoriyarvi Massif, Russia) |
title_full |
Ti-Nb Mineralization of Late Carbonatites and Role of Fluids in Its Formation: Petyayan-Vara Rare-Earth Carbonatites (Vuoriyarvi Massif, Russia) |
title_fullStr |
Ti-Nb Mineralization of Late Carbonatites and Role of Fluids in Its Formation: Petyayan-Vara Rare-Earth Carbonatites (Vuoriyarvi Massif, Russia) |
title_full_unstemmed |
Ti-Nb Mineralization of Late Carbonatites and Role of Fluids in Its Formation: Petyayan-Vara Rare-Earth Carbonatites (Vuoriyarvi Massif, Russia) |
title_sort |
ti-nb mineralization of late carbonatites and role of fluids in its formation: petyayan-vara rare-earth carbonatites (vuoriyarvi massif, russia) |
publisher |
MDPI AG |
publishDate |
2018 |
url |
https://doi.org/10.3390/geosciences8080281 https://doaj.org/article/20a07cb7f2cb40d2a86cb2e534ae038a |
genre |
Northwest Russia |
genre_facet |
Northwest Russia |
op_source |
Geosciences, Vol 8, Iss 8, p 281 (2018) |
op_relation |
http://www.mdpi.com/2076-3263/8/8/281 https://doaj.org/toc/2076-3263 2076-3263 doi:10.3390/geosciences8080281 https://doaj.org/article/20a07cb7f2cb40d2a86cb2e534ae038a |
op_doi |
https://doi.org/10.3390/geosciences8080281 |
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Geosciences |
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8 |
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8 |
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281 |
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1766149445373657088 |