The volcanic rocks of the Submarine Edifice of La Gomera island. compositional features

摘要

The Submarine Edifice rocks are the oldest rocks in La Gomera. This edifice is made up of submarine lavaand breccias, with marine sediments associated, all of which is transverse by a very dense network ofdiques. This essay shows the first geochemical and mineralogical submarine volcanic rocks data. Theserocks are intensely altered and have an alkaline chemical affinity. Compositions vary between alkalinebasalts and trachyandesites, and all of them show typical Within Plate and Ocean Island basalts immobileelements contents. The latter Subaerial Edifice volcanic rocks are similar in composition, although they areslightly less alkaline and they have less evolved types