Minerales de tierras raras en las carbonatitas del Complejo Basal de Fuerteventura (Islas Canarias)

Abstract

The Fuerteventura carbonatites appear in the Complejo Basal as veins, breccias and shear bands in the coastline between Puerto de la Pena and Cueva de Lobos, and in the Esquinzo ravine zone. These carbonatites are formed by calcite mainly and apatite, aegirine-augite, albite, orthoclase-sanidine, biotite, epidote and ore minerals occur in lower amounts, and as accessory minerals titanite, zircon, garnet, celestite, barite, brithdlite, allanite, pyrochlore and monazite. Geochemical analysis o f these carbonatites show high values] of REE between 511 and 7,372 ppm, with high relation LREE/HREE. Microprobe studies show that these elements mainly are associated with phosphates (britholite, monazite and apatite), silicates (allanite and titanite), oxides (pyrochlore), carbonates (bastnaesite) and sulphates (barite). The carbonatites have been generated in the last magmatic-hydrothermal crystallization phases of the alkaline intrusive complexes of Fuerteventura