Relaciones de campo y geoquímica de las carbonatitas de Esquinzo-Agua Salada, NW de Fuerteventura, Islas Canarias

Abstract

Carbonatites are rather uncommon rocks, the origin of which still stands a subject of debate, especially regarding if they crystallize from primary carbonatitic melts from the mantle, or if they are generated, by some magmatic differentiation process, from an alkaline-silicate parent magma. The Esquinzo-Agua Salada carbonatites are associated, both in space and time, to an ensemble of alkaline silicate lithologies comprising, from ultramafic-mafic (perovskite-clinopyroxenites-ijolitic rocks) to felsic (nepheline-syenites) types. In this work, field relationships between both groups of lithologies as well as the main geochemical characteristics of the carbonatites, which are compared to those of the alkaline silicate rocks, are presented. Both aspects seem to indicate an origin for the carbonatites by liquid immiscibility, from a CO2-rich, alkaline silicate parental magma