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@article{1092118, author = {Galliski, Miguel and Florencia, MarquezandZavalia and Lira, Raul and Cempírek, Jan and Škoda, Radek}, article_location = {QUEBEC}, article_number = {4}, doi = {http://dx.doi.org/10.3749/canmin.50.4.873}, keywords = {granitic pegmatite; dumortierite; holtite; chrysoberyl; kyanite; tourmaline; Virorco; Argentina}, language = {eng}, issn = {0008-4476}, journal = {Canadian Mineralogist}, title = {MINERALOGY AND ORIGIN OF THE DUMORTIERITE-BEARING PEGMATITES OF VIRORCO, SAN LUIS, ARGENTINA}, volume = {50}, year = {2012} }
TY - JOUR ID - 1092118 AU - Galliski, Miguel - Florencia, Marquez-Zavalia - Lira, Raul - Cempírek, Jan - Škoda, Radek PY - 2012 TI - MINERALOGY AND ORIGIN OF THE DUMORTIERITE-BEARING PEGMATITES OF VIRORCO, SAN LUIS, ARGENTINA JF - Canadian Mineralogist VL - 50 IS - 4 SP - 873-894 EP - 873-894 PB - MINERALOGICAL ASSOC CANADA SN - 00084476 KW - granitic pegmatite KW - dumortierite KW - holtite KW - chrysoberyl KW - kyanite KW - tourmaline KW - Virorco KW - Argentina N2 - The Virorco dumortierite-bearing pegmatites, in Sierra de San Luis, Argentina, are a group of thin, steeply dipping dikes one to 10 cm thick. The pegmatits are symmetrically zoned, with quartz, albite, oligoclase, tourmaline- and dumortierite-group minerals, muscovite and kyanite as the major phases; the accessory and trace minerals include beryl, chrysoberyl, garnet, fluorapatite, columbite-(Mn) to tantalite-(Mn), pollucite, gahnite, zircon, uraninite and thorite. Holmquistite was found in the exocontact assemblage. Primary textures of magmatic origin were partially disrupted by partial replacements by later minerals and incipient to strong deformation. Five textural and compositional types of tourmaline-supergroup minerals were identified in the different pegmatitic zones, ranging from dravite-rich compositions to rossmanite, passing through schorl and Mn-rich elbaite. At least four generations of the dumortierite-holtite minerals are texturally and compositionally represented in these dikes: the earliest dumortierite replaces muscovite and tourmaline, locally together with a second generation that grades into As-poor holtite. The third generation is represented by overgrowths or individual crystals of As-poor and As-rich holtite; it is commonly overgrown by the last generation of dumortierite enriched in As. The chemical evolution of dumortierite-group minerals is characterized by an increase of Ta, Nb and minor As, followed by an extensive enrichment in As (+ Sb + Bi) along with gradual decrease in Ta + Nb. The initial stage comprises the magmatic crystallization of a highly evolved and boron-rich peraluminous melt. The second stage was a prograde medium-pressure metamorphism, with a fluid-phase-related episode of crystallization. The most likely source of the initial melt is an extraction of residual melt from an almost completely crystallized rare-element parental pegmatite. ER -
GALLISKI, Miguel, Marquez-Zavalia FLORENCIA, Raul LIRA, Jan CEMPÍREK a Radek ŠKODA. MINERALOGY AND ORIGIN OF THE DUMORTIERITE-BEARING PEGMATITES OF VIRORCO, SAN LUIS, ARGENTINA. \textit{Canadian Mineralogist}. QUEBEC: MINERALOGICAL ASSOC CANADA, 2012, roč.~50, č.~4, s.~873-894. ISSN~0008-4476. Dostupné z: https://dx.doi.org/10.3749/canmin.50.4.873.
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