Petrogénesis de los basaltos alcalinos de La Garrotxa, región volcánica del NE de España 28

• Autores: J. M. Gregorio López Ruiz, Eduardo Rodríguez Badiola, José-María Cebriá
• Localización: Geogaceta, ISSN 0213-683X, Nº. 1, 1986, págs. 28-31
• Idioma: español
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• Resumen

  • Compositional trends and trace elements abundance in leucite-basanites, nephelinebasanites and olivine basalts from La Garrotxa (NE Spain region), suggest that the parental magma were originated from an homogeneous lherzolite source, strongly enriched in incompatible elements (between x15-x4 the chondritic values for the highly incompatible elements and between x5-x2 for the moderately incompatible), in which neither kaersutite, phlogopite or apatite remained as residual phases. The leucite-basanite magmas were derived by lower degrees of melting (7-10%) than the basanite s.s. and the olivine basalt magmas (13-15%). Except sorne primary leucite-basanites, the lavas from La Garrotxa underwent a moderate fractionation (=20%) of ol + cpx + mg, in proportion that range between 75-40%, 55-10% and 15-0%, respectively.