The distribution of rare metals in the LCT pegmatites from the Giraúl Field, Angola

The Giraúl granitic pegmatite field in Angola is composed of five pegmatite types, the most evolved belong to the beryl-columbite, beryl-columbite-phosphate and spodumene types. Pegmatites are concentrically zoned with increased grain size toward a quartz core; the most evolved pegmatites have well-...

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Autores: Gonçalves, Antonio Olimpio, Melgarejo i Draper, Joan-Carles, Alfonso Abella, María Pura, Amores Casals, Sandra, Paniagua, Andrés, Neto, André Buta, Alves Morais, Eduardo, Camprubí, Antoni
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2019
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/158762
Acceso en línea:https://hdl.handle.net/2445/158762
Access Level:acceso abierto
Palabra clave:Pegmatites
Minerals
Cendres volcàniques
Angola
Volcanic ash
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spelling The distribution of rare metals in the LCT pegmatites from the Giraúl Field, AngolaGonçalves, Antonio OlimpioMelgarejo i Draper, Joan-CarlesAlfonso Abella, María PuraAmores Casals, SandraPaniagua, AndrésNeto, André ButaAlves Morais, EduardoCamprubí, AntoniPegmatitesMineralsCendres volcàniquesAngolaPegmatitesMineralsVolcanic ashAngolaThe Giraúl granitic pegmatite field in Angola is composed of five pegmatite types, the most evolved belong to the beryl-columbite, beryl-columbite-phosphate and spodumene types. Pegmatites are concentrically zoned with increased grain size toward a quartz core; the most evolved pegmatites have well-developed replacement units. These pegmatites are rich in Nb-Ta oxide minerals and the field has a moderate interest for critical elements such as Ta and Hf. Tourmaline, garnet and micas occur as accessory minerals. The abundance of Zr and Nb-Ta minerals increases with the evolution of the pegmatites, as well as the proportions of beryl and Li-rich minerals. The Ta/(Ta + Nb) ratio in Nb-Ta oxide minerals and the Hf/(Hf + Zr) ratio in zircon also increase with the evolution of the pegmatites and within each pegmatite body from border to inner zones, and especially in the late veins and subsolidus replacements. Textural patterns and occurrence of late veins with Ta-rich minerals suggest that Nb and especially Ta can be enriched in late hydrothermal fluids exsolved from the magma, along with Hf and other incompatible elements as Sn, U, Pb, Sb and Bi.MDPI2019info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://hdl.handle.net/2445/158762Articles publicats en revistes (Mineralogia, Petrologia i Geologia Aplicada)reponame:Dipòsit Digital de la UBinstname:Universidad de BarcelonaInglésReproducció del document publicat a: https://doi.org/10.3390/min9100580Minerals, 2019, vol. 9, num. 10, p. 580-https://doi.org/10.3390/min9100580cc-by (c) Gonçalves, Antonio Olimpio et al., 2019http://creativecommons.org/licenses/by/3.0/esinfo:eu-repo/semantics/openAccessoai:diposit.ub.edu:2445/1587622026-05-27T06:46:51Z
dc.title.none.fl_str_mv The distribution of rare metals in the LCT pegmatites from the Giraúl Field, Angola
title The distribution of rare metals in the LCT pegmatites from the Giraúl Field, Angola
spellingShingle The distribution of rare metals in the LCT pegmatites from the Giraúl Field, Angola
Gonçalves, Antonio Olimpio
Pegmatites
Minerals
Cendres volcàniques
Angola
Pegmatites
Minerals
Volcanic ash
Angola
title_short The distribution of rare metals in the LCT pegmatites from the Giraúl Field, Angola
title_full The distribution of rare metals in the LCT pegmatites from the Giraúl Field, Angola
title_fullStr The distribution of rare metals in the LCT pegmatites from the Giraúl Field, Angola
title_full_unstemmed The distribution of rare metals in the LCT pegmatites from the Giraúl Field, Angola
title_sort The distribution of rare metals in the LCT pegmatites from the Giraúl Field, Angola
dc.creator.none.fl_str_mv Gonçalves, Antonio Olimpio
Melgarejo i Draper, Joan-Carles
Alfonso Abella, María Pura
Amores Casals, Sandra
Paniagua, Andrés
Neto, André Buta
Alves Morais, Eduardo
Camprubí, Antoni
author Gonçalves, Antonio Olimpio
author_facet Gonçalves, Antonio Olimpio
Melgarejo i Draper, Joan-Carles
Alfonso Abella, María Pura
Amores Casals, Sandra
Paniagua, Andrés
Neto, André Buta
Alves Morais, Eduardo
Camprubí, Antoni
author_role author
author2 Melgarejo i Draper, Joan-Carles
Alfonso Abella, María Pura
Amores Casals, Sandra
Paniagua, Andrés
Neto, André Buta
Alves Morais, Eduardo
Camprubí, Antoni
author2_role author
author
author
author
author
author
author
dc.subject.none.fl_str_mv Pegmatites
Minerals
Cendres volcàniques
Angola
Pegmatites
Minerals
Volcanic ash
Angola
topic Pegmatites
Minerals
Cendres volcàniques
Angola
Pegmatites
Minerals
Volcanic ash
Angola
description The Giraúl granitic pegmatite field in Angola is composed of five pegmatite types, the most evolved belong to the beryl-columbite, beryl-columbite-phosphate and spodumene types. Pegmatites are concentrically zoned with increased grain size toward a quartz core; the most evolved pegmatites have well-developed replacement units. These pegmatites are rich in Nb-Ta oxide minerals and the field has a moderate interest for critical elements such as Ta and Hf. Tourmaline, garnet and micas occur as accessory minerals. The abundance of Zr and Nb-Ta minerals increases with the evolution of the pegmatites, as well as the proportions of beryl and Li-rich minerals. The Ta/(Ta + Nb) ratio in Nb-Ta oxide minerals and the Hf/(Hf + Zr) ratio in zircon also increase with the evolution of the pegmatites and within each pegmatite body from border to inner zones, and especially in the late veins and subsolidus replacements. Textural patterns and occurrence of late veins with Ta-rich minerals suggest that Nb and especially Ta can be enriched in late hydrothermal fluids exsolved from the magma, along with Hf and other incompatible elements as Sn, U, Pb, Sb and Bi.
publishDate 2019
dc.date.none.fl_str_mv 2019
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv https://hdl.handle.net/2445/158762
url https://hdl.handle.net/2445/158762
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv Reproducció del document publicat a: https://doi.org/10.3390/min9100580
Minerals, 2019, vol. 9, num. 10, p. 580-
https://doi.org/10.3390/min9100580
dc.rights.none.fl_str_mv cc-by (c) Gonçalves, Antonio Olimpio et al., 2019
http://creativecommons.org/licenses/by/3.0/es
info:eu-repo/semantics/openAccess
rights_invalid_str_mv cc-by (c) Gonçalves, Antonio Olimpio et al., 2019
http://creativecommons.org/licenses/by/3.0/es
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv MDPI
publisher.none.fl_str_mv MDPI
dc.source.none.fl_str_mv Articles publicats en revistes (Mineralogia, Petrologia i Geologia Aplicada)
reponame:Dipòsit Digital de la UB
instname:Universidad de Barcelona
instname_str Universidad de Barcelona
reponame_str Dipòsit Digital de la UB
collection Dipòsit Digital de la UB
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15,300724

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