Evolución contrastada de elementos trazas (Th-U-Y-HREE) entre granitos fraccionados de tipo-l y tipo-S de la Sierra de Guadarramareflejo en la química de minerales accesorios
- C. Villaseca
- C. Pérez-Soba
- J. González del Táñago
ISSN: 1576-5172
Año de publicación: 2004
Título del ejemplar: IV Congreso Geológico de España (Zaragoza, 12-15 julio, 2004)
Número: 6
Páginas: 141-144
Tipo: Artículo
Otras publicaciones en: Geotemas (Madrid)
Resumen
I- and S-type granites from the Sierra de Guadarrama (Spanish Central System) display contrasting evolutionary patterns for Th, Y and REE. This chemical contrast is controlled by the behaviour of accessory phases. In felsic ¡-type granites the low fractionation of some phosphates (xenotime, monazite) permits the enrichment in the HESE hosted in those accessories. Moreover, contrasts in trace element contents in accessory phases (zircon, xenotime, monazite) appear between I- and S-type granites. Th, Y and HREE contents in monazite and xenotime are lower in S-type granites compared to those in less peraluminous ones. This is reflected in lower Th/U ratios in monazites and xenotimes from S-type granites