Esquinzo ultra-alkaline complex, Fuerteventura Basal Complex, Fuerteventura, Las Palmas Province, Canary Islands, Spaini

Regional Level Types
Esquinzo ultra-alkaline complex	Complex
Fuerteventura Basal Complex	Complex
Fuerteventura	Island Council
Las Palmas Province	Province
Canary Islands	Group of Autonomous Communities
Spain	Group of Countries

Calciocarbonatites appear in the Basal Complex as veins, breccias, and shear bands.

In the northern part of the island of Fuerteventura there is a series of outcrops belonging to the Ultra-alkaline series and are particularly interesting because of the complexity of its lithology and how good their outcrops.

We can distinguish three zones:

— Massif of "Barranco de Agua Salada" located in a small ravine tributary of Esquinzo;

— Massif of "Los Jablitos";

— Massif of "The Montañetas".

The latter two are both situated in the ravine of "Los Encantados", also a tributary of Esquinzo.

In these outcrops a great variety of rocks such as Ijolites, Syenites, Nepheline Syenite, Nephelinites, Carbonatites (Sovites-Alvikites) are found with pegmatitic zones and zones of brecciation, and complex processes of metasomatism and recrystallization.

A major 100 m-wide anastomosing normal-dextral shear zone divides the Esquinzo ultra-alkaline complex into two blocks showing important different lithological features:

— In the southwestern block, perovskite-bearing pyroxenites and perovskite-bearing melteigite-ijolite rocks cut by late nephelinite and phonolitic nephelinite dykes are predominant, while carbonatites occur in limited amounts.

- In contrast, in the northeastern block, there are no nephelinite or phonolitic nephelinite dykes, but carbonatites, nepheline syenites and pegmatite ijolites are very abundant. Cross-cutting relationships between the different lithologies are shown in an E–W geological cross-section.

Other Regions, Features and Areas containing this locality

References