Show simple item record

dc.contributor.authorAlfonso Abella, María Pura
dc.contributor.authorHamid, Sarbast
dc.contributor.authorGarcía-Vallès, Maite
dc.contributor.authorLlorens González, Teresa
dc.contributor.authorLópez Moro, Francisco Javier
dc.contributor.authorTomasa Guix, Oriol
dc.contributor.authorCalvo Torralba, Daniel
dc.contributor.authorGuasch Cascallo, Eduard
dc.contributor.authorAnticoi Sudzuki, Hernán Francisco
dc.contributor.authorOliva Moncunill, Josep
dc.contributor.authorParcerisa Duocastella, David
dc.contributor.authorGarcía Polonio, Francisco
dc.contributor.otherUniversitat Politècnica de Catalunya. Departament d'Enginyeria Minera, Industrial i TIC
dc.coverage.spatialeast=-7.024306700000011; north=42.172831; name=32558 Penouta, Ourense, Espanya
dc.identifier.citationAlfonso, P., Hamid, S., García-Vallès, M., Llorens, T., López-Moro, J., Tomasa, O., Calvo, D., Guasch, E., Anticoi, H., Oliva, J., Parcerisa, D., García Polonio, F. Textural and mineral-chemistry constraints on columbite-group minerals in the Penouta deposit: evidence from magmatic and fluid-related processes. "Mineralogical magazine", Maig 2018, vol. 82, Supplement S1, p. S199-S222.
dc.description.abstractThe Penouta Sn-Ta deposit, in the northwest of Spain, is a greisenized granitic cupola where Ta minerals occur mainly as disseminations in a leucogranite body intruded in Precambrian–Lower Cambrian gneisses and mica-schists. This leucogranite is a medium- to fine-grained inequigranular rock consisting mainly of quartz, albite, K-feldspar and muscovite. Accessory minerals are mainly of spessartine, zircon, cassiterite, Nb-Ta oxides, monazite, xenotime, native bismuth and pyrite. The alteration processes were mainly albitization, muscovitization and kaolinitization. This leucogranite is peraluminous and P-poor, with 0.03–0.07 wt.% P2O5, 900–1500 ppm Rb, 30–65 ppm Cs, 120–533 ppm Li, 80–140 ppm Ta, 51–81 ppm Nb and up to 569 ppm of Sn. Mineralogical characterization of Nb-Ta oxide minerals was determined by X-ray diffraction, scanning electron microscopy, electron microprobe analysis and mineral liberation analysis. Mn-rich members of the columbite-group minerals (CGM) are the most common Ta-bearing phases, but microlite, wodginite, tapiolite and Ta-rich cassiterite occur also. CGM crystals are commonly zoned concentrically, with a Nb-rich core surrounded by a Ta-rich rim, with a sharp boundary between them. Convoluted zoning occurs also. Dissolution textures resulting from the corrosion of columbite and tantalite rims, in particular, are common. TheMn/(Mn + Fe) ratio varies between 0.33 and 0.97 and the Ta/(Ta + Nb) ratio between 0.07 and 0.93. Wodginite and microlite formed as late replacements of CGM and occur associated with tantalite and cassiterite. Subhedral to anhedral cassiterite crystals, usually up to 200 µmacross, occur in two generations: the earlier one is Nb,Ta-poor whereas in the later generation, the Ta content can reach >9 wt.%of Ta2O5 and 1.7 wt.%of Nb. The presence of a fluid phase in the apical zone of the granite, probably related to the separation of a fluid/vapour of the melt, could explain the sponge-like textures, the Ta enrichment associated with these textures, the occurrence of Taenriched mineral phases (microlite and wodginite) and their common interstitial character.
dc.rightsAttribution 4.0 International
dc.subjectÀrees temàtiques de la UPC::Enginyeria civil::Enginyeria de mines
dc.subjectÀrees temàtiques de la UPC::Enginyeria civil::Geologia::Mineralogia
dc.titleTextural and mineral-chemistry constraints on columbite-group minerals in the Penouta deposit: evidence from magmatic and fluid-related processes
dc.subject.lemacTàntal (Química inorgànica)
dc.contributor.groupUniversitat Politècnica de Catalunya. GREMS - Grup de Recerca en Mineria Sostenible
dc.description.peerreviewedPeer Reviewed
dc.rights.accessOpen Access
dc.description.versionPostprint (published version)
dc.relation.projectidinfo:eu-repo/grantAgreement/EC/H2020/642201/EU/Increasing yield on Tungsten and Tantalum ore production by means of advanced and flexible control on crushing, milling and separation process/OptimOre
upcommons.citation.authorAlfonso, P.; Hamid, S.; García-Vallès, M.; Llorens, T.; López-Moro, J.; Tomasa, O.; Calvo, D.; Guasch, E.; Anticoi, H.; Oliva, J.; Parcerisa, D.; García Polonio, F.
upcommons.citation.publicationNameMineralogical magazine
upcommons.citation.volume82, Supplement S1

Files in this item


This item appears in the following Collection(s)

Show simple item record

Except where otherwise noted, content on this work is licensed under a Creative Commons license: Attribution 4.0 Generic