Petrogénesis de los diques alcalinos de Errigoiti (magmatismo de edad Cretácico superior en la Cuenca Vasco-Cantábrica)
- Fernando Sarrionandia Eguidazu 1
- Manuel Carracedo Sánchez 1
- Jon Errandonea-Martin 1
- Luis Eguiluz Alarcón 1
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1
Universidad del País Vasco/Euskal Herriko Unibertsitatea
info
Universidad del País Vasco/Euskal Herriko Unibertsitatea
Lejona, España
ISSN: 0213-683X
Año de publicación: 2017
Número: 61
Páginas: 107-110
Tipo: Artículo
Otras publicaciones en: Geogaceta
Resumen
In the basque village of Errigoiti (Biscay) outcrops a series of dikes emplaced into the Upper Cretaceous volcanosedimentary sequence. These dikes, constituted by alkali rocks, exhibit a wide compositional range (SiO2=48.78-61.92%), which includes alkali basalts, trachy-andesites and tephri-phonolites. The most basic terms have similar geochemical characteristics to those of the OIB-type basalt s. None of the samples represents a primary melt, nevertheless their elemental ratios Dy/Yb (2.1-2.3), La/Yb (20-28) and Ce/Y (3.2-3.5) suggest that the melts which fed these dikes where generated by low degrees of partial melting (1.6-1.9%) of an enriched asthenospheric mantle at ca. 70 km in depth. The lithological variety observed would be the result of olivine and clinopyroxene fractionation from an original basic magma.