The 3-D inverse modelling of a magnetic anomaly measured over the NW submarine edifice of the
volcanic island of Gran Canaria revealed a large, reversely-magnetized, elongated structure following
an ENE-WSW direction, which we interpreted as a sill-like magmatic intrusion emplaced during the
submarine growth of this volcanic island, with a volume that could represent up to about 20% of the
whole island. The elongated shape of this body suggests the existence of a major crustal fracture in the
central part of the Canary Archipelago which would have favoured the rapid ascent and emplacement of
magmas during a time span from 0.5 to 1.9 My during a reverse polarity chron of the Earth’s magnetic
field prior to 16 Ma. The agreement of our results with those of previous gravimetric, seismological and
geodynamical studies strongly supports the idea that the genesis of the Canary Islands was conditioned
by a strike-slip tectonic framework probably related to Atlas tectonic features in Africa. These results do
not contradict the hotspot theory for the origin of the Canary magmatism, but they do introduce the
essential role of regional crustal tectonics to explain where and how those magmas both reached the
surface and built the volcanic edifices.
