Search results for "Fuerteventura"
showing 5 items of 5 documents
An overview of the geochemical characteristics of oceanic carbonatites: New insights from Fuerteventura carbonatites (Canary islands)
2021
The occurrence of carbonatites in oceanic settings is very rare if compared with their continental counterpart, having been reported only in Cape Verde and Canary Islands. This paper provides an overview of the main geochemical characteristics of oceanic carbonatites, around which many debates still exist regarding their petrogenesis. We present new data on trace elements in minerals and whole-rock, together with the first noble gases isotopic study (He, Ne, Ar) in apatite, calcite, and clinopyroxene from Fuerteventura carbonatites (Canary Islands). Trace elements show a similar trend as Cape Verde carbonatites, almost tracing the same patterns on multi-element and REE abundance diagrams. 3…
Trace elements and noble gases (He, Ne, Ar) isotopic study of Fuerteventura carbonatites: implications for their mantle source
Procesos hidrotermales con enriquecimiento en REE en las carbonatitas de Fuerteventura: evidencias en minerales accesorios
2021
Carbonatitic dykes that crop out in the central western part of Fuerteventura Basal Complex (Ajuy, Punta de la Nao), were affected by the Miocene intrusive event responsible for contact metamorphism and partial melting of part of the alkaline-carbonatitic complex. Textural characteristics, monazite enriched in LREE (La, Ce, Nd) formation processes in microfractures that affect zircon crystals, show carbonatite interactions with hydrothermal fluids and partial REE remobilization. Pyrochlore is the main mineral carrier of rare earth elements (sum REE=216694 ppm), with high LREE (LaN=185816 and CeN=165209) with respect to HREE (YbN=2589 and LuN=1814) with a rather steep pattern (La/Yb)N=72 in …
Hydrothermal processes with REE enrichment in Fuerteventura carbonatites: evidences in accessory minerals
2021
Los diques carbonatíticos que afloran en la parte centro-occidental del Complejo Basal de Fuerteventura (Ajuy, Punta de la Nao), fueron afectados por el evento intrusivo mioceno responsable del metamorfismo de contacto y fusión parcial de parte del complejo alcalino-carbonatítico. Las características texturales, los procesos de formación de monacita enriquecida en LREE (La, Ce, Nd) en microfracturas que afectan a los cristales de zircón, evidencian interacciones de las carbonatitas con fluidos hidrotermales y removilización parcial de REE. El pirocloro es el principal mineral reservorio de tierras raras (suma REE=216694 ppm), con valores elevados de LREE (LaN=185816 y CeN=165209) respecto a…
Microthermometry of fluid inclusions in calcite from Fuerteventura carbonatites: composition and formation conditions
2022
The petrographic analysis in calcite minerals in carbonatitic dykes from Fuerteventura Basal Complex (Ajuy, Punta de la Nao) shows the presence of isolated primary fluid inclusions, corroborating their magmatic origin instead of a late-stage origin. Micro-thermometric studies in calcite show a restricted range of apparent eutectic temperature (Te*= -21.7 – -21.0 °C) and final ice melting temperatures (Tim= -3.2 – -2.1. °C). Homogenization temperatures and pressures are in the range of 140-210 °C and 4-16 bars respectively. Our results suggest the binary NaCl-H2O system as a characterizing chemical system in studied fluid inclusions, with the presence of low salinity fluids (≈ 5 wt. % NaCleq…