Merino Martínez, EnriqueVillaseca González, CarlosPérez-Soba Aguilar, Cecilia MaríaLópez García, José Ángel2023-06-202023-06-2020080213-683Xhttps://hdl.handle.net/20.500.14352/49609The Montes de Toledo Batholith comprises several felsic peraluminous granitic plutons characterized by the presence of two Al2SiO5 polymorphous: andalusite and sillimanite (as fibrolitic variety). Textural features indicate an igneous origin for andalusite, variably replaced by muscovite and fibrolite around it. We propose a combination of factors to explain this probable magmatic reaction: the decrease in minor element contents of andalusite (Fe, Mg, Mn, Ti) and the increase of volatiles in the melt (B, P, F, H2O) along its cooling. This chemical variation influences the stability of both polymorphs, crystallizing initially igneous andalusite and, when the Fe content decreases, the sillimanite, in relation with muscovite, in a restricted P-T space close to the granite solidus conditions.spajournal articlehttp://www.sociedadgeologica.es/publicaciones_geogaceta.htmlopen access552.3(234.1)Peraluminous granitesAluminum silicate stabilityMineral chemistryIberian Hercynian BeltPetrología