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dc.contributor.author
Colombo, Fernando
dc.contributor.author
Lira, Raul
dc.contributor.author
Dorais, Michael J.
dc.date.available
2018-08-16T18:12:02Z
dc.date.issued
2010-03
dc.identifier.citation
Colombo, Fernando; Lira, Raul; Dorais, Michael J.; Mineralogy and crystal chemistry of micas from the A-type El Portezuelo Granite and related pegmatites, Catamarca (NW Argentina); Czech Geological Society; Journal of Geosciences; 55; 1; 3-2010; 43-56
dc.identifier.issn
1802-6222
dc.identifier.uri
http://hdl.handle.net/11336/55962
dc.description.abstract
The A-type El Portezuelo Pluton (Catamarca, NW Argentina) is parental to an intragranitic suite of pegmatites of NYF-type affiliation (miarolitic class, miarolitic-rare earth element subclass, with features more similar to those reported for the gadolinite-fergusonite type). This study was performed on samples from the host granite and several zones of pegmatites, including crystals growing in miarolitic cavities and fine-grained overgrowths. Micas from the granite and massive pegmatites are rather homogeneous, but crystals coming from miarolitic cavities are usually sharply zoned with monocrystalline trioctahedral inner zones overgrown by polycrystalline dioctahedral rims. Dioctahedral micas are always paragenetically later. Micas from the granite are intermediate members of the annite-siderophyllite series. From the outer pegmatite zones inwards the substitution (SiLi)([4]AlFe)-1 in trioctahedral micas leads to compositions intermediate between siderophyllite and polylithionite, up to the composition KLiFe2+Al(AlSi3)O10(F,OH)2 (formerly called zinnwaldite). Dioctahedral micas also show a trend from near end-member muscovite to (Fe, Mg, Li)-rich muscovite (phengite), according to the substitution (R2+Si)([4]Al[6]Al)-1, where R2+ = Fe, Mg, Mn; there is a compositional gap between dioctahedral and trioctahedral micas. Zoned individual crystals have trioctahedral cores enriched in Fe, Mn and F; Na, Li and Ti are usually also enriched in the cores, whereas Mg is usually depleted compared with the dioctahedral rims. Micas in El Portezuelo are the most important F-bearing species (for their elevated F contents and their modal abundance) and they also have a major role in the distribution of Li and Rb. The overall evolutionary trend is very similar to that found at the Pikes Peak Batholith (Colorado USA) and is characteristic of NYF-type granite-miarolitic pegmatite systems.
dc.format
application/pdf
dc.language.iso
eng
dc.publisher
Czech Geological Society
dc.rights
info:eu-repo/semantics/openAccess
dc.rights.uri
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
dc.subject
Chemical Evolution
dc.subject
Fluorine
dc.subject
Lithium
dc.subject
Nyf-Type Pegmatites
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Siderophyllite
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Zinnwaldite
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Meteorología y Ciencias Atmosféricas
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Ciencias de la Tierra y relacionadas con el Medio Ambiente
dc.subject.classification
CIENCIAS NATURALES Y EXACTAS
dc.title
Mineralogy and crystal chemistry of micas from the A-type El Portezuelo Granite and related pegmatites, Catamarca (NW Argentina)
dc.type
info:eu-repo/semantics/article
dc.type
info:ar-repo/semantics/artículo
dc.type
info:eu-repo/semantics/publishedVersion
dc.date.updated
2018-08-13T17:16:39Z
dc.identifier.eissn
1803-1943
dc.journal.volume
55
dc.journal.number
1
dc.journal.pagination
43-56
dc.journal.pais
República Checa
dc.journal.ciudad
Praga
dc.description.fil
Fil: Colombo, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Ciencias de la Tierra. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones en Ciencias de la Tierra; Argentina
dc.description.fil
Fil: Lira, Raul. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Museo de Paleontología; Argentina
dc.description.fil
Fil: Dorais, Michael J.. University Brigham Young; Estados Unidos
dc.journal.title
Journal of Geosciences
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/doi/http://dx.doi.org/10.3190/jgeosci.058
dc.relation.alternativeid
info:eu-repo/semantics/altIdentifier/url/http://www.jgeosci.org/detail/jgeosci.058
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